Veterinary Advice Online: Dog Spaying (Spaying a Female Dog).

Dog spaying (bitch spaying procedure) - otherwise known as female neutering, dog sterilisation, "fixing", desexing, ovary and uterine ablation, uterus removal or by the medical term: ovariohysterectomy - is the surgical removal of a female dog's ovaries and uterus for the purposes of canine population control, medical health benefit, genetic-disease control and behavioral modification. Considered to be a basic component of responsible female dog ownership, the spaying of female dogs is a simple and common surgical procedure that is performed by veterinary clinics all over the world. This page contains everything you, the pet owner, need to know about dog spaying (female dog desexing). Dog spaying topics are covered in the following order:



1. What is spaying?

2. Canine spaying pros and cons - the reasons for and against spaying a dog.
2a. The benefits of dog spaying (the pros of dog spaying) - reasons for spaying your dog.
2b. The disadvantages of desexing (the cons of dog spaying) - why some people choose not to spay their female dogs.

3. Information about dog spaying age: when to spay a dog.
3a. Current dog desexing age recommendations.
3b. Spaying a puppy - information about the early spay and neuter of young puppies.

4. Canine spaying procedure (dog spay operation) - a step by step pictorial guide to dog spay surgery.

5. Dog Spaying After Care - all you need to know about caring for your female dog after spaying surgery.
Includes information on feeding, bathing, exercising, wound care, pain relief and stopping dogs from licking surgical wounds.

6. Post Spay Complications - Possible surgical and post-surgical (post-op) complications and side effects of spaying a dog.
6a. Pain after dog spaying surgery (e.g. dog walking stiffly, not wanting to sit down and so on).
6b. A large 'lump' or 'swelling' at the dog spay operation site (hernias and seromas).
6c. Wound break-down - partial or complete break down of the skin stitches.
6d. Wound infection.
6e. Suture-site reactions - swollen, red skin around sutures or stitches.
6f. Excessive wound hemorrhage (excessive bleeding during or after dog spaying surgery).
6g. Failure to ligate (tie off) the ovarian or uterine (uterus) blood vessels adequately.
6h. Peritonitis.
6i. Ureter laceration.
6j. Post-operative renal failure (kidney failure).
6k. Anaesthetic death.

7. Late complications or problems associated with spaying female dogs.
7a. Weight gain after dog spaying.
7b. Ovarian remnants (incomplete dog spay) - the spayed dog goes into heat after dog spaying surgery.
7c. Incontinence after dog spaying.

8. Frequently asked questions (FAQs) and myths about spaying female dogs:
8a. Myth 1 - All desexed bitches gain weight (get fat).
8b. Myth 2 - Without her reproductive organs, a female dog (bitch) won't "feel like a woman".
8c. Myth 3 - Female dogs need to have sex before being desexed.
8d. Myth 4 - Female dogs should be allowed to give birth to a litter before being spayed.
8e. Myth 5 - Vets just advise neutering for the money not for my dog's health.
8f. FAQ 1 - Why won't my veterinarian clean my dog's teeth at the same time as spaying her?
8g. FAQ 2 - Why shouldn't my vet vaccinate my dog whilst she is under anaesthetic?
8h. FAQ 3 - Can my dog be spayed whilst she is in heat?
8i. FAQ 4 - Spaying a pregnant dog - can my pregnant dog be spayed?
8j. FAQ 5 - My pregnant dog needed a caesarean (C-section) - can she be spayed at the same time?
8k. FAQ 6 - Incontinence after dog spaying - will spaying make my dog incontinent?
8l. FAQ 7 - Is dog spaying safe? It's just a routine procedure isn't it?
8m. FAQ 8 - My veterinarian offered to perform a pre-anaesthetic blood screening test - is this necessary?
8n. FAQ 9 - When is canine spaying surgery high-risk or not safe to perform?

9. The cost (price) of spaying female dogs:
9a. The typical cost of spaying a female dog at a veterinary clinic.
9b. Where and how to source discount and low cost spaying.
9c. Free canine spaying.

10. Alternatives to spaying your dog:
10a. Dog birth control method 1 - separate the male dog from the female and prevent her from roaming.
10b. Dog birth control method 2 - neuter your male dog and keep your female dog inside.
10c. Dog birth control method 3 - "the contraceptive pill" and hormonal female oestrus (heat) suppression.
10d. Dog birth control method 4 - "male pill" - fertility suppressing implants (contraceptives) for male dogs.
10e. Canine birth control method 5 - male canine vasectomy.



WARNING - IN THE INTERESTS OF PROVIDING YOU WITH COMPLETE AND DETAILED INFORMATION, THIS SITE DOES CONTAIN MEDICAL AND SURGICAL IMAGES THAT MAY DISTURB SENSITIVE READERS.







1. What is spaying?

Dog spaying or desexing is the surgical removal of a female (bitch) dog's internal reproductive structures including her ovaries (the site of ova/egg production), Fallopian tubes, uterine horns (the two long tubes of uterus where the fetal puppies develop and grow) and a section of her uterine body (the part of the uterus where the uterine horns merge and become one body). The picture on the right shows a dog uterus that has been removed by dog spaying surgery - it is labeled to give you a clear illustration of the reproductive structures that are removed during surgery.

Basically, the parts of the female reproductive tract that get removed are those which are responsible for egg (ova) production, embryo and fetus development and the secretion of the major female reproductive hormones (oestrogen and progesterone being the main female reproductive hormones). Removal of these structures plays a huge role in canine population control (without eggs, the female dog can not produce young; without a uterus, there is nowhere for the unborn puppies to develop); canine genetic disease control (female dogs with genetic disorders can not pass on their inheritable disease conditions to any young if they can not breed); the prevention and/or treatment of various medical disorders (spaying prevents and/or treats a number of ovarian and uterine diseases as well as various hormone-enhanced medical conditions) and female dog behavioral modification (e.g. estrogen is responsible for many female dog behavioral traits that some owners find problematic - e.g. roaming, blood spotting during proestrus, attractiveness and attraction to male dogs - and dog spaying, by removing the ovarian source of female hormones, may help to resolve these issues).







2. Canine spaying pros and cons - reasons for and against spaying a dog.

2a. Benefits of spaying (pros of spaying) - reasons for spaying your dog.

There are many reasons why veterinarians and pet advocacy groups recommend the desexing of entire female dogs. Many of these reasons are listed below, however the list is by no means exhaustive.

1. The prevention of unwanted litters:
Pet overpopulation and the dumping of unwanted litters of puppies (and kittens) is an all-too-common side effect of irresponsible pet ownership. Every year, thousands of unwanted puppies and older dogs are surrendered to shelters and pounds for rehoming or dumped on the street (street-dumped animals ultimately end up dying from starvation, predation or transmissible canine diseases or finding their way into pounds and shelters that may or may not be able to find homes for them). Many of these animals do not ever get adopted from the pounds and shelters that take them in and those that don't get adopted often end up being euthanased. This sad waste of healthy life can be reduced by not letting pet dogs breed indiscriminately and the best way of preventing any accidental, unwanted breeding from occurring is through the routine neutering of all non-stud (non-breeder) female dogs (and male dogs too, but this is another page).

Author's note: The deliberate breeding of family dogs should never be considered an easy way to make a quick buck. A lot of cost and effort and expertise goes into producing a quality litter of puppies for profitable sale. And that's only if nothing goes wrong! If your bitch needs a caesarean section at one in the morning or develops a severe infection after whelping (e.g. metritis, mastitis), then all of your much planned profits will rapidly turn into financial losses (the vet fees for these kinds of treatments are high). On top of that, if you fail to do your homework and you breed poor quality puppies or poorly socialized pups that won't sell, then you've just condemned some of those young animals to a miserable life of being dumped in shelters or on the streets.

2. The reduction of stray and feral dog populations:
By having companion dogs spayed at young ages, they are unable to become pregnant. This results in fewer litters of unwanted puppies being born which, in return, benefits not just those unwanted pups (dumped or shelter-surrendered pups can often lead a tough, neglected life), but also society and the environment in general. A proportion of the unwanted puppies that are dumped into the environment (e.g. the Australian bush) do survive and grow up to become feral dogs, which in turn reproduce to produce more feral dogs. Feral and stray dog populations pose a significant risk of predation to native wildlife; they account for many thousands of dollars in stock and farming losses (livestock killing - see image opposite); they carry diseases that may affect humans (e.g. rabies, worms, dog-bites) and their pets (e.g. rabies, parasites, parvo virus, distemper); they fight with domestic pets, inflicting nasty dog-fight wounds and abscesses; they kill smaller domestic pets (e.g. pet cats, small dogs, rabbits and livestock); they steal the food of domestic pets and they place a huge financial and emotional burden on the pounds, shelters and animal rescue groups which have to deal with them.

3. To reduce the spread of inferior genetic traits, genetic diseases and congenital deformities:
Dog breeding is not merely the production of puppies, it is the transferral of genes and genetic traits from one generation to the next in a breed population. Pet owners and breeders should desex female dogs that have conformational, coloring and temperamental traits, which are unfavorable or faulty to the breed as a whole, to reduce the spread of these defects further down the generations. Female dogs with heritable genetic diseases and congenital defects/deformities should also be desexed to reduce the spread of these genetic diseases to their offspring.

Some examples of proven-heritable or suspect-heritable diseases that we select against when choosing to spay dogs include: hip and elbow dysplasia, polycystic kidney disease (PKD), cryptorchidism, collie eye anomaly, lysosomal storage diseases, amyloidosis and dilated cardiomyopathy. There are many others.


Picture: This is a close up image of the vulva of a bitch (?) with hermaphrodism (canine hermaphrodite). Her clitoris is massively enlarged, forming a miniature penis that protrudes from the vulva. Animals with hermaphrodism are of poor breeding quality (they are often, but not always, infertile) and many may even have significant sex-chromosome defects (e.g. XX/XY chimeras). These animals should be desexed and not bred from.


Dog uterus images: These photos show a female dog uterus that has one normal uterine horn (the horn on the left side) and one non-existent, undeveloped uterine horn (the uterus horn on the right side). This dog was born with this defect (it was found by accident during dog spaying surgery). Because the undeveloped right uterine horn can not produce any puppies, this defect would naturally result in a greatly reduced fecundity (fecundity refers to the number of pups born per litter) for this particular bitch, were she to be used as a breeding dog. Any female with such a significant reproductive tract birth defect should never be chosen as a breeding animal because, should the defective uterine condition be found to be heritable, then the generations succeeding her could be afflicted with a similar genetic tendency towards poor litter sizes (never a desirable trait in a breeding population).

4. The prevention and/or treatment of ovarian and uterine diseases:
It is difficult to contract an ovarian or uterine disease if you have no ovaries or uterus. Early dog spaying prevents female dogs from contracting a range of ovarian and uterine diseases and disorders including: uterine cancer, ovarian cancer, polycystic ovaries, metritis or endometritis (severe uterine or uterine wall inflammation, often with bacterial infection, usually seen after whelping), mucometra (a uterus full of glandular mucus), cystic endometrial hyperplasia (large cysts in the wall of the uterus that predispose dogs to pyometra), pyometra or pyometron (infection and abscessation of the uterus that is similar to metritis and endometritis, but not usually associated with pregnancy and whelping), ectopic pregnancy (pregnancy outside of the uterus), uterine prolapse and uterine torsion.


Image 1: This is an ultrasound image of a large ovarian cancer (4-5cm in diameter) that was taken from a 5kg dog. The black spaces/holes that you can see throughout the mass are mutated 'ovarian follicles' (fluid-filled cystic structures akin to those "true ovarian follicles" which produce the ova/eggs in a normally-functioning ovary) that the cancerous ovarian follicular cells have produced in an attempt to mimic their normal function within the ovary.
Image 2: This is a photographic image of a post-mortem performed on a dog who died from pyometra (infection of the uterus). The dog's uterus (which looks like an enormous number "3" laying on its side) was massively enlarged and completely full of infection and pus - a classic case of canine pyometra. The dog died because bacteria from the infected uterus invaded the dog's blood stream, causing septicaemia and blood poisoning. The condition could have been prevented by desexing surgery.


Image 3: This is a rabbit uterus with two major problems, both of which could have been prevented by early rabbit spaying surgery. The uterus contains a large (2cm diam) uterine cancer. It also contains a uterine intussusception. A uterine intussusception is a condition whereby one section of a uterine horn telescopes into another section of the uterine horn. The telescoped uterine horn becomes strangled inside the other section of uterine horn (as seen in this image), causing it to die and rot and become necrotic (decaying tissue). You can see the dead telescoped section of uterus in this image - it is green in color and gangrenous.

5. The prevention or reduction of hormone-induced diseases:
It is well known that entire female dogs do suffer from a range of diseases and medical conditions that are directly associated with high blood estrogen and/or progesterone levels (the hormones produced by the ovaries). These conditions include: vaginal hyperplasia (a large swelling of the roof of the vaginal passage, which results in a large red or pink ball of flesh protruding from the bitch's vulva - see image below); mammary neoplasia (breast cancer in dogs is greatly influenced by hormones and bitches spayed prior to their first season almost never develop the condition); mammary enlargement; cystic endometrial hyperplasia; pyometron (the development of uterine conditions favorable to the development of uterine infection or pyometra is greatly reliant on seasonal ovarian reproductive hormone fluctuations); pseudopregnancy (false pregnancy or phantom pregnancy with accompanied signs of 'expecting' including: nesting behaviours, abdominal enlargement, breast enlargement and even lactation) and certain desexing-responsive skin disorders (e.g. estrogen-induced dermatoses).

Some entire bitches develop follicular cysts on their ovaries (also termed polycystic ovaries - ovaries with too many actively-secreting ovarian follicles), which produce excessive amounts of oestrogen, well above the quantities usually seen in a normal entire bitch. Excessive estrogen is termed hyperestrogenism and it can result in a number of estrogen-induced behavioral problems manifesting (e.g. nymphomania, excessive libido, mounting toys) as well as a range of potentially life-threatening medical problems including: bone marrow suppression (oestrogen toxicity shuts down the bone marrow, causing complete failure of production of red blood cells, white blood cells and platelets), blackening of the skin (hyperpigmentation), hairloss and/or poor coat quality and abnormally increased mammary development.

High levels of ovary-derived reproductive hormones (e.g. progesterone) can also interfere with the management of other medical conditions. Diabetes mellitus is a good example of this. Progesterone inhibits the action of insulin on the body cells' insulin receptors, producing a condition called 'insulin resistance' or Type 2 diabetes (similar to parturient diabetes or 'pregnancy diabetes' seen in women). What essentially happens is that any insulin (e.g. Caninsulin, Actrapid and others) given to the pet to manage its diabetes does not work as effectively in the presence of progesterone. This can make the animal's diabetes very difficult to control every time it has a season and it is one of the main reasons why vets recommend the desexing of diabetic dogs as part of the management of the disease. Other diseases whose severity or management can also be adversely affected by high reproductive hormone levels include acromegaly, epilepsy, Cushing's disease (Hyperadrenocorticism) and generalised Demodex mites.

Desexing removes the main source of oestrogen and progesterone from the animal's body (the ovaries), which not only prevents the onset of these diseases or conditions, but can even help to control or manage these diseases if they are already present.


Photograph: This is an image of the vulva of a bitch with vaginal hyperplasia, also called vaginal prolapse (some people, incorrectly, term this condition uterine prolapse, however, uterine prolapse is a different condition altogether). The red or pink swelling protruding from the vulval opening is the roof of the dog's vagina. This condition is hormonal and can usually be resolved through dog spaying surgery.


Picture: Whilst not exactly a disease per se, many owners elect to get their female dogs spayed so that they will cease displaying all of the annoying signs of pro-estrus and oestrus (heat), in particular vulval enlargement and blood spotting (dog "period") in the house. The image above shows the vulva of a dog in pro-estrus (early season). The vulva is swollen and a blood-tinged discharge is coming from the vulval opening.

6. The prevention or reduction of hormone-mediated behavioural problems:
The ovaries are responsible for producing estrogen and progesterone: the hormones that make female animals look and act like female animals. It is the ovaries that make female dogs exhibit the kinds of "female" hormone-dependent behaviors normally attributed to the entire animal. Entire female dogs are more likely to exhibit sexualised behaviors including: aroused interest in males of their own species; nymphomania (excessive sexual and mating drive) and excessive affection and sexual interest towards their owners (in-heat dogs can often drive their owners nuts by constantly putting their bottoms in their owners' faces, rubbing up against them and mounting toys and legs). Pre-heat dogs just coming into season can sometimes be moody and unpredictable (PMS?) and they may threaten or bite owners and other household pets who get too close to them or touch them on the rump. Some of the more dominant cycling females will even display unwanted dominance and territorial behaviors such the marking of territory with urine (although much more commonly exhibited by entire male dogs, some dominant females will also exhibit urine marking in the house) and the guarding of food, nesting sites and other resources. Additionally, entire, in-heat female dogs are much more likely than neutered animals are to leave their yards and roam the countryside looking for males and trouble. Roaming is a troublesome habit because it puts other animals (wildlife and other pets) and humans at risk of harm from your canine pet and it puts the roaming pet at risk from all manner of dangers including: predation by other animals, attacks by other dogs, cruelty by humans, poisoning, envenomation (e.g. snake bite) and motor vehicle strikes. The spaying of entire female dogs may help to reduce some of these problematic hormone-mediated behaviours.

Author's note: Fighting between dogs, even dogs living within the same house-hold, is more common when dogs are left entire and undesexed. Although fighting is much more common between entire male dogs, fighting can also occur between male and female dogs when a male attempts to mate with a female who is not yet receptive to his advances. Such advances can result in the female dog attacking the male and receiving wounds in return. Fighting can also occur between entire bitches in the same household when one of the bitches (particularly a subordinate female) comes into heat. The onset of estrus (heat or season) affects the in-season-subordinate's smell and, consequently, her perceived standing within the bitch hierarchy (in wild dog society, only the alpha or top female is permitted to cycle and breed), which, if taken as a threat by the dominant females in the house-hold, can result in very aggressive fighting and severe injury. Owners of fighting dogs often spend hundreds to thousands of dollars treating their pets for fight wounds and dog-fight abscesses. By reducing their attractiveness to male dogs and also their perceived threat/challenge towards other intact female dogs, dog spaying reduces the incidence of fighting and its secondary complications (clawed and lacerated eyes, dog-fight abscesses and so on).

Important author's note: Whilst desexing or neutering is usually valuable in reducing many forms of aggression in entire male dogs, some forms of aggression in female dogs can actually become worse after desexing surgery. This is thought to occur because of the loss of progesterone that occurs as a result of ovary removal. Progesterone hormone has a calming, mood-quietening effect on many female animals and the loss of it can result in mood-alteration and an increased tendency towards certain forms of aggression. If your bitch is already aggressive and you are considering having her desexed, I recommend that you consult with your vet or an animal behaviouralist before dog spaying surgery is performed in order to determine whether this surgery is appropriate for her at this current time.

7. The reduction of male dog attraction:
When a female dog comes into heat, she releases pheromones and hormones in her urine that notify male dogs of her increased fertility. These hormones and pheromones can be detected by male dogs from many miles away. It is, therefore, not uncommon for the owners of undesexed, in-heat female dogs to have male dogs constantly coming into their yards at all times of the day and night.

This is a problem for many reasons. Firstly, the wandering dogs will fight amongst themselves, producing a lot of ruckus and injury in the middle of the night. Secondly, the trespassing dogs will fight with the house owner's dogs, resulting in injuries and costly dog fight abscesses and, potentially, the spread of diseases like rabies. The roaming dogs may also predate upon the house-owner's other pets, including any small domesticated pets (cats, rabbits, poultry etc.) and livestock. Thirdly, the roaming dogs will void urine and feces in the female-dog owner's yard, which kills the plants and grass and leaves behind a pungent and noxious odor. Sometimes, the male dogs will even venture into the female-dog owner's house (they certainly will if there is a pet flap), where they will steal food and mate with the in-heat female in question. If the female dog does escape the house, she is almost certain to be mated and to fall pregnant. If the female dog is living outside in a backyard, even a seemingly-well-fenced yard, then she is also highly likely to become pregnant (male dogs will climb and scale great heights and dig under fences and push through heavy gates to access and mate with a female dog on heat).

By spaying all of the female dogs in your household, there will be nothing to attract the male dogs into your yard and, consequently, the problem of trespassing stray dogs will be solved.



2b. The disadvantages of desexing dogs (the cons of spaying dogs) - why some people choose not to spay their female dogs.

There are many reasons why some individuals, breeders and pet groups choose not to advocate the sterilization of entire female dogs. Many of these reasons have been listed below, however the list is by no means exhaustive.

1. The dog may become overweight or obese:
Studies have shown that spayed and neutered animals probably require around 25% fewer calories to maintain a healthy bodyweight than entire female animals of the same size do. This is because a neutered animal has a lower metabolic rate than an entire animal does (it therefore needs fewer calories to maintain its bodyweight). Because of this, what tends to happen is that most owners, unaware of this fact, continue to feed their spayed dogs the same amount of food calories after the surgery that they did prior to the surgery, with the result that their canine pets become fat. Consequently, the myth of automatic post-desexing obesity has become perpetuated and, as a result, many owners simply will not consider desexing their female dogs because of the fear of them gaining weight and developing weight-related problems.

Author's note: The fact of the matter is that dogs will not become obese simply because they have been desexed. They will only become obese if the post-dog-spaying drop in their metabolic rate is not taken into account and they are fed the same amount of food calories as an entire animal.

Author's note: Those of you who care about your finances might even be able to see the benefits of desexing here. A spayed dog potentially costs less to feed than an entire animal of the same weight does and, therefore, neutering your animal may well save you money in the long run.

2. Desexing equates to a loss of breeding potential and valuable genetics:
There is no denying this. If a dog or cat or horse or other animal is the 'last of its line' (i.e. the last puppy in a long line of pedigree breeding dogs), a breeder or pet owner's choice to desex that animal and, therefore, not pass on its valuable breed genetics will essentially spell the end for that breeding lineage.

Author's opinion point: of all the reasons given here that argue against the desexing of female dogs, this is probably the only one that has any real merit. Desexing does equate to a loss of breeding potential. In an era where many unscrupulous breeders and pet owners ("backyard breeders" we call them) will breed any low-quality dog, regardless of breed traits and temperament, to make a quick buck, the good genes for breed soundness, breed traits and good temperament are needed more than ever. Desexing a purebred female dog with good breed characteristics, good temperament and no genetically heritable defects/diseases will count as a loss for that breed's quality in general, particularly if there are a lot of subquality females around saturating the breeding circles.

3. Loss of estrogen or underexposure to estrogen as a result of desexing (especially early age dog spaying) may result in the underdevelopment of feminine characteristics, the retention of immature juvenile behaviours and cause urinary incontinence:
The ovaries are responsible for producing progesterone and estrogen: the hormones that make mature female animals look and act like female animals. It is the hormones produced by the ovaries that cause female animals to develop the distinctive body characteristics normally attributed to the entire female animal. These include: increased vulval size and development; mature breast (mammary) development and enlargement; increased maturity and emotional development; increased sex drive and libido and, controversially, improved bladder control and continence.

Desexing, particularly early age desexing (prior to the first season), may limit the development of mature feminine features such that they remain immature and juvenile-looking throughout life (i.e. the mammaries remain tiny and the vulva remains tiny). In overweight individuals (see image opposite) underdevelopment of the vulva as a result of early-age desexing (termed vulval hypoplasia), can result in the tiny vulva being 'swallowed up' within the roll of fat that borders the vulval region. Encased within this fat roll, the vulva and perivulval skin (skin surrounding the vulva) will tend to become scalded with urine and prone to retaining moisture, both of which will tend to result in vulval dermatitis, vaginal yeast infections, vulval itchiness and, potentially, an increased risk of ascending urinary tract infections.

Early desexing may also cause the spayed pet to remain emotionally and mentally immature well into adulthood (i.e. the animal retains many of its juvenile, puppyish behavioural characteristics). Not that this is always a problem. Emotionally immature dogs retain a lot of the playfulness and curiosity of their puppy-hood: cute traits that most dog-loving owners are all too keen to keep hold of. The only time that this inappropriate immaturity can become an issue is when the pet in question is meeting other adult dogs. A fully grown dog with overly-playful puppy qualities pouncing up to another adult dog is likely to be misread by that other dog and bitten.

The incontinence issue is still a matter of debate (see FAQ 6, section 8, for more info). It has long been said that estrogen plays a significant role in the development and maturation of bladder sphincter tone (basically, how 'tight' and resistant to urine leakage the bladder neck is) and that early age spaying can result in a weakness of this bladder tone, such that the animal is prone to incontinence and urine leakage (i.e. dribbling urine involuntarily, particularly during sleep). Certainly, the once-common use of oestrogen products (e.g Stilbestrol) in the management of female dog incontinence problems does support this idea as does the fact that most of our incontinent pets (esp. dogs) are desexed females. As will be discussed in FAQ 6, however, although there is much merit to the desexing-causing-incontinence idea (particularly in the case of dogs and early-age spaying), there is still some controversy about whether it is the loss of oestrogen per se that produces the problem or whether it is the spay technique itself (i.e. changing spay techniques may alleviate the risk).

Either way, regardless of the underlying causative mechanism, when it does occur, post-desexing incontinence and urine soiling can be a major problem for the animal and its owner. This is particularly so if the animal lives indoors (wetting on the bed or carpet is unhygienic and poorly tolerated) or in a place with high blowfly populations (urine soiled bottoms are prone to flystrike). The risk of the condition happening is certainly a significant reason why many owners (in particular, dog owners) might decide against having their female animals desexed.

4. As an elective procedure, dog spaying is risky:
Certainly, female dog desexing is a more risky and invasive procedure to perform than male dog desexing is. Having said that, the incidence of major complications associated with routine (i.e. non-pregnant, non-diseased uterus) dog spaying procedures is still very low and, therefore, no reason to avoid having a dog spayed. See sections 6 and 7 for more on spay complications.

5. As an elective procedure, dog spaying costs too much:
The high cost of veterinary services, including desexing, is another big reason why some pet owners choose not to get their pets desexed. See section 9 for more on the costs of dog spaying.

Author's note: Having said this, the costs of canine caesarian section or having a pregnant dog desexed are significantly higher than the costs of a routine dog spay.

6. The dog will "no longer be a woman" without her ovaries and uterus:
It sounds silly, but it is a very common reason why many owners refuse to get their female dogs spayed. See myth 2 (section 8b) for more.







3. Information about dog spaying age: when to spay a dog.

The following two subsections discuss desexing age recommendations and how they have been established as well as the pros and cons of early age (8-16 weeks) dog spaying (spaying a puppy).

3a. Current dog spaying age recommendations.

In Australia and throughout much of the world, it has always been recommended that female dogs be spayed at around 5-7 months of age and older. As far as the "older" goes, the closer to the 5-7 months of age mark the better - there is less chance of a female dog becoming pregnant or developing a ovarian or uterine disorder or a hormone-mediated medical condition if she is desexed at a younger age. In addition to this, it has always been advised that it is best if a female dog is desexed prior to the onset of her first season as this will greatly reduce the risks of the animal developing mammary cancer (breast cancer) in the future.

The reasoning behind this 5-7 month age specification is mostly one of anaesthetic safety for elective procedures.

When asked by owners why it is that a dog needs to wait until 5-7 months of age to be spayed, most veterinarians will simply say that it is much safer for them to wait until this age before undergoing a general anaesthetic procedure. The theory is that the liver and kidneys of very young animals are much less mature than those of older animals and therefore less capable of tolerating the effects of anaesthetic drugs and less effective at metabolizing them and breaking them down and excreting them from the body. Younger animals are therefore expected to have prolonged recovery times and an increased risk of suffering from severe side effects, in particular liver and kidney damage, as a result of general anaesthesia. Consequently, in order to avoid such problems, many vets will choose not to anesthetize a young puppy until at least 5 months of age for any elective procedure, including dog spaying.

The debate:
Whether this 5-7 month age specification for general anaesthesia and desexing is valid nowadays (2008 onwards), however, is much less clear and is currently the subject of debate. The reason for the current desexing-age debate is that the 5-7 month age specification was determined ages ago, way back in the days when animal anaesthesia was nowhere near as safe as it is now and relied heavily upon drugs that were more cardiovascularly depressant than modern drugs (e.g. put more strain on the kidneys and liver) and required a fully-functioning, almost-adult liver and kidney to metabolize and excrete them from the body. Because modern animal anaesthetic drugs are so much safer on young animals than the old drugs used to be, there is increasing push to drop the age of desexing in veterinary practices. This puts us onto the topic of early age dog spaying (see next section - 3b).

Are there any disadvantages to desexing at the normal time of 5-7 months of age?
Just as there are disadvantages associated with desexing an animal at a very young age (see section 3b), there are also some disadvantages associated with spaying at the usually-stated age of 5-7 months:

• Some people find it inconvenient to wait until 5-7 months of age to desex.
  
• There is the chance that an early-maturing female dog may be able to mate and produce unwanted puppies before this age. This is not only bad for the underage mother dog (a mother dog allowed to have pups at under 5-7 months is not physically or emotionally mature enough to have puppies - she is still a baby herself), but it potentially adds to the number of unwanted litters being destroyed and/or dumped.
  
• For people who choose to have their pets microchipped during anaesthesia, there is an inconvenient wait of 5-7 months before this can be done. If the animal gets lost prior to this age, the unchipped dog may fail to find its way home.
  
• Some of the behavioural issues commonly associated with entire female animals may become manifest before the time of the desexing age recommendations (e.g. urine marking, dog aggression, roaming). These behavioural problems, once established, may persist and remain problematic even after the animal is sterilized.

3b. Spaying a puppy - information about the early spay and neuter of young puppies.

As modern pet anesthetics have become a lot safer, with fewer side effects, the debate about the recommended age of canine spaying has been reopened in the veterinary world with some vets now allowing their clients to opt for an early-age spay or neuter, provided they appreciate that there are greater, albeit minimal, anaesthetic risks to the very young pet when compared to the more mature pet. In these situations, dog owners can now opt to have their male and female pets desexed as young as 8-9 weeks of age (the vet chooses anaesthetic drugs that are not as cardiovascularly depressant and which do not rely as heavily upon extensive liver and kidney metabolism and excretion).

Powerful supporters of the early spay and neuter - in 1993, the AVMA (American Veterinary Medical Association) advised that it supported the early spay and neuter of young cats and dogs, recommending that puppies and kittens be spayed or neutered as early as 8-16 weeks of age.

IMPORTANT - because of the rising problems of pet and feral animal overpopulation, it is now the law in many states (e.g. Canberra, Australian Capital Territory) for cats to be desexed prior to 12 weeks of age. In the case of Canberra dogs, the law (as of 2009) specifies that all male and female dogs now be desexed unless their owner is in possession of a breeder's licence. No canine desexing age has yet been specified, so dog owners can still opt to desex their pets earlier (from 8 weeks) or at puberty (5-7 months), depending on their own personal preferences. This dog spaying law may soon change, however, in line with cat spaying laws, making it compulsory for dog owners to have their pets desexed before a certain age. In some countries, states and territories, age specifications may already be in place for the spaying of dogs. Owners of dogs (and cats) need to check their local state laws on pet neutering ages - it may be compulsory in your area for your pet to undergo early age desexing regardless of any minor increases in anaesthetic risk that might be incurred.

The advantages of the early spay and neuter of young dogs:
Certainly, there are some obvious advantages to choosing to desex an animal earlier rather than later. These include the following:

• People do not have to wait 5-7 months to spay their pets. The procedure can be over and done with earlier.
  
• Dogs spayed very early will not attain sexual maturity and will therefore be unable to fall pregnant and give birth to any puppies. This role in canine population control is why most shelters choose to neuter early.
  
• Dogs spayed very early will not attain sexual maturity and will therefore be unable to fall pregnant. Consequently, owners of female dogs will not have to deal with the dilemma of having an 'accidentally' pregnant pet and all of the ethical issues this problem poses (e.g. What do I do with the pups? It is right to desex a pregnant animal before the puppies are born? Is it right to give a dog an abortion? ... and so on). Likewise, veterinary staff also benefit from not having to perform dog desexing surgery on pregnant animals, a procedure that many staff find very confronting.
  
• It makes it possible for young puppies (6-12 weeks old) to be sold by breeders and pet-shops already desexed. This again helps to reduce the incidence of irresponsible breeding - dogs sold already desexed cannot reproduce.
  
• For owners who choose to get their pets microchipped during anaesthesia, there is no inconvenient wait of 5-7 months before this can be done.
  
• Some of the behavioural problems and concerns commonly associated with entire female animals may be prevented altogether if the puppy is desexed well before achieving sexual maturity (e.g. marking territory, roaming, estrus blood spotting, in-heat aggression).
  
• Some of the medical problems and concerns commonly associated with entire female animals may be prevented altogether if the puppy is desexed well before achieving sexual maturity. In particular, breast cancer (mammary cancer) in dogs is almost non-existent in animals that are desexed prior to their first season.
  
• From a veterinary anaesthesia and surgery perspective, the duration of dog spaying surgery and anaesthesia is much shorter for a smaller, younger animal than it is for a fully grown, mature animal. I take about 5-10 minutes to neuter a female puppy of about 9 weeks of age compared to about 15-25 minutes for an older female and even longer if she is large-breed, obese, in-heat or pregnant.
  
• The post-anaesthetic recovery time is quicker and there is less bleeding associated with an early spay or neuter procedure.


• From a veterinary business perspective, the shorter duration of surgery and anaesthesia time is good for business. More early age dog spays can be performed in a day than mature dog spays and less anaesthetic is used on each individual, thereby saving the practice money per procedure.
  
• Routine, across-the-board, early spay and neuter by shelters avoids the need for a sterilization contract to be signed between the shelter and the prospective dog owner. A sterilization contract is a legal document signed by people who adopt young, non-desexed puppies and kittens, which declares that they will return to the shelter to have that dog or cat desexed when it has reached the recommended sterilization age of 5-7 months. The problem with these sterilisation contracts is that, very often, people do not obey them (particularly if the animal seems to be "purebred"); they are rarely enforced by law and, consequently, the adopted animal is often left undesexed and able to breed and the cycle of pet reproduction and dumped litters continues.

The disadvantages associated with the early spay and neuter of young puppies:
There are also several disadvantages associated with choosing to desex an animal earlier rather than later. Many of these disadvantages were outlined in the previous section (3a) when the reasons for establishing the 5-7 month desexing age were discussed and include:

• Early age anaesthesia and desexing is never going to be as safe as performing the procedure on an older and more mature dog. Regardless of how safe modern anaesthetics have become, the liver and kidneys of younger animals are considered to be less mature than those of older animals and therefore less capable of tolerating the effects of anaesthetic drugs and less effective at metabolizing them and breaking them down and excreting them from the body. Even though it is very uncommon, there will always be the occasional early age animal that suffers from potentially life-threatening side effects, in particular liver and kidney damage, as a result of young age anaesthesia. Having said that, the anaesthesia time is heaps quicker and blood loss is greatly reduced, so maybe it all balances out ...
  
• There is an increased risk of severe hypothermia (cold body temperatures) and hypoglycemia (low blood sugar) occurring when young animals are anesthetized. This hypothermia predisposition is caused by the young puppy's increased body surface area (larger area for heat to be lost), reduced ability to shiver and reduced body fat covering (fat insulates against heat loss). The predisposition towards hypoglycemia is the result of a reduced liver ability to produce glucose from stores of glycogen and body fat, as well as the fact that these stores of fat and glycogen are smaller in the young animal.


• Loss of sex hormone production at a very early age, as a result of desexing, may result in extremely immature development of feminine body characteristics. In particular, the animal's vulva and mammaries will remain very small and immature. Vulval hypoplasia (a small, juvenile vulva) may become a problem in overweight animals as they will often develop a roll of fat over their vulva which can predispose them to vulval dermatitis, urine scalding and vulval skin infections (+/- urinary tract infections).
  
• Early neutering may result in retained juvenile behaviours inappropriate to the animal's age later on. A fully grown dog with overly-playful puppy qualities pouncing up to another adult dog is likely to be misread by that other dog and bitten.


• Early neutering may result in urinary incontinence later on (but so can later neutering too).


• Early age neutering prevents dog breeders from being able to accurately determine which puppies will be valuable stud animals in the future (i.e. it is too early to tell when they are only pups). Because desexing equates to a loss of breeding potential and valuable genetics, many breeders choose to only desex their dogs after they have had some time to grow (after all, it is not possible to look at a tiny puppy and determine whether or not it will have the right color, conformation and temperament traits to be a breeding and showing dog). This allows the breeder time to determine whether or not the animal in question will be a valuable stud animal or not.
  
• Early spaying and neutering will not 100% reduce pet overpopulation and dumping problems when a large proportion of dumped animals are not merely unwanted litters, but purpose-bought, older pets that owners have grown tired of, can't manage, can't train and so on. Those people, having divested themselves of a problem pet, then go and buy a new animal, thereby keeping the breeders of dogs in good business and promoting the ongoing over-breeding of animals.

Author's note: at the time of this writing (2009), I was working as a veterinarian in a high output animal shelter in Australia. Because shelter policy was not to add to the numbers of litters being born irresponsibly by selling entire animals, all dogs, including puppies, were required to be desexed prior to sale. Consequently, it was not unusual for us to desex male and female puppies and kittens at early ages (anywhere from 8 weeks of age upwards). Hundreds of puppies and kittens passed under the surgeon's knife every year on their way to good homes and I must say from experience that the incidence of intra- and post-operative complications that were a direct result of underage neutering was exceedingly low.

4. Dog spaying procedure (dog spay operation) - a step by step pictorial guide to dog spaying surgery.

As stated in the opening section, dog spaying is the surgical removal of a female dog's internal reproductive organs. During the procedure, each of the female dog's ovaries and uterine horns are removed along with a section of the dog's uterine body. And, to be quite honest, from a general pet owner's perspective, this is probably all of the information that you really need to know about the surgical process of desexing a female dog.



Desexing basically converts this ...


Image: This is a preoperative picture of an anesthetized female cat, already clipped, just prior to cat spaying surgery (our apologies for having a feline image on a dog page - Pet Informed will replace this image when a clipped dog photo is available). The belly of a female dog just prior to dog spaying surgery would look similar after pre-surgical clipping.



... into this ...


Image: This is a photo of the same cat after her reproductive organs have been removed surgically. All you can see from the outside is a small suture in the middle of her belly. Similar stitches appear in the belly skin of female dogs after they have been desexed.



... by removing these.


Image: This is a picture of a canine reproductive tract, which has been removed by sterilisation surgery. You can clearly see the ovaries, uterine horns and uterine body: these are the main sites of hormone production, ova/egg production and puppy development in the female animal.

For those of you readers just dying to know how it is all done, the following section contains a step by step guide to the pre-surgical and surgical process of desexing a female dog (ovariohysterectomy procedure). There are many surgical desexing techniques available for use by veterinarians, however, I have chosen to demonstrate the very commonly-used "midline incision approach" of dog spaying. Diagrammatical images are provided to illustrate the process and I have included links to my photographic step-by-step pages on cat spaying procedure (similar to dog spaying procedure) and pregnant cat spaying procedure.

Once again, Pet Informed apologizes for the use of feline spay surgery photographs in this section on dog spaying surgery. We will replace these images once dog spaying photos become available. The use of these cat spay images to illustrate the points being made should not interfere with your understanding of dog spaying procedure as the two spay procedures are almost identical in appearance.



DOG SPAYING PROCEDURE STEP 1:
Preparation of the animal prior to entering the veterinary clinic.

Preparation of an animal for any surgical procedure begins in the home.

Your animal should be fasted (not fed any food) the night before a surgery so that she has no food in her stomach on the day of surgery. This is important because dogs that receive a general anaesthetic may vomit if they have a full stomach of food and this could lead to potentially fatal complications. The dog could choke on the vomited food particles or inhale them into its lungs resulting in severe bacterial or chemical pneumonia (severe fluid and infection build-up within the air spaces of the lungs).

The dog should be fed a small meal the night before surgery (e.g. 6-8pm at night) and then not fed after this. Any food that the animal fails to consume by bedtime should be taken away to prevent it from snacking throughout the night.

Young puppies and kittens (8-16 weeks) should not be fasted for more than 8 hours prior to surgery.

Water should not be withheld - it is fine for your canine pet to drink water before admission into the vet clinic.

Please note that certain animal species should not be fasted prior to surgery or, if they are fasted, not fasted for very long. For example, rabbits and guinea pigs are not generally fasted prior to surgery because they run the risk of potentially fatal intestinal paralysis (gut immotility) from the combined effects of not eating and receiving anaesthetic drugs. Ferrets have a rapid intestinal transit time (the time taken for food to go from the stomach to the colon) and are generally fasted for only 4 hours prior to surgery.

If you are going to want to bath your female dog, do this before the surgery because you will not be able to bath her for 2 weeks immediately after the surgery (we don't want the healing spay wounds to get wet). Your vet will also thank you for giving him/her a nice clean animal to operate on.



DOG SPAYING PROCEDURE STEP 2:
The dog is admitted into the veterinary clinic.
When an animal is admitted into a veterinary clinic for desexing surgery, a number of things will happen:

• 1) You should arrive at the vet clinic with your fasted dog in the morning. Vet clinics usually tell owners what time they should bring their pet in for surgical admission and it is important that you abide by these admission times and not be late. If you are going to be late, do at least ring your vet to let him know. Vet clinics need to plan their day around which pets arrive and do not arrive for surgery in the morning. A pet turning up late throws all of the day's planning out the window. Do remember that your vet has the right to refuse to admit your pet for dog spaying surgery if you arrive late.
• 2) The animal will be examined by a veterinarian to ensure that she is healthy for dog spaying surgery. Her gum color will be assessed, her heart and chest listened to and her temperature taken to ensure that she is fit to operate on. Some clinics will even take your pet's blood pressure. This pre-surgical examination is especially important if your pet is old (greater than 7-8 years). In addition to the routine health check, your dog will also be examined in order to determine whether or not she is in-heat or pregnant. If she is, the vet will discuss the added costs and risks of the dog spaying procedure with you and you can decide whether you want to continue with the operation or post-pone it.
  
• 3) You will be given the option of having a pre-anaesthetic blood panel done. This is a simple blood test that is often performed in-house by your vet in order to assess your dog's basic liver and kidney function. It may help your vet to detect underlying liver or kidney disease that might make it unsafe for your dog to have an anaesthetic procedure. Better to know that there is a problem before the pet has an anaesthetic than during one! Old dogs (>8 yrs) in particular should have a pre-anaesthetic blood panel performed (many clinics insist upon it), but cautious owners can elect to have young pets tested too.
  
• 4) The dangers and risks of having a general anaesthetic procedure will be explained to you. Please remember that even though dog spaying is a "routine" surgery for most vet clinics, animals can still die from surgical and/or anaesthetic complications. Animals can have sudden, fatal allergic reactions to the drugs used by the vet; they can have an underlying disease that no-one is aware of, which makes them unsafe to operate on; they can vomit whilst under anaesthesia and choke and so on. Things happen (very rarely, but they do) and you need to be aware of this before signing an anaesthetic consent form. Remember that the risks are greater with large-breed, obese, in-heat and pregnant animals.
  
• 5) You will be given a quote for the surgery. Remember that the costs of dog spaying surgery will increase if your dog is in heat (in season) or pregnant.
  
• 6) You will be asked to sign an anaesthetic consent form. As with human medicine, it is becoming more and more common these days for pet owners to sue vets for alleged malpractice. Vets today require clients to sign a consent form before any anaesthetic procedure is performed so that owners can not come back to them and say that they were not informed of the risks of anaesthesia, should there be an adverse event.
  
• 7) Make sure that you provide accurate contact details and leave your mobile phone on so that your vet can get in contact with you during the day! Vets may need to call owners if a spaying complication occurs, if an extra procedure needs to be performed on the pet or if the pet has to stay in overnight.
  
• 8) Your dog will be admitted into surgery and you will be given a time to return and pick it up. It is often best if you ring the veterinary clinic before picking your pet up just in case it can not go home at the time expected (e.g. if surgery ran late).

DOG SPAYING PROCEDURE STEP 3:
The dog will receive a sedative premedication drug (premed) and, once sedated, it will be given a general anaesthetic and clipped and scrubbed for surgery.

The female dog is normally given a sedative-containing premedication drug before surgery, which is designed to fulfill many purposes. The sedative calms the dog, making it slip into anaesthesia more peacefully; the sedative often contains a pain relief drug (analgesic), which reduces pain during and after surgery and the sedative action results in lower quantities of anaesthetic drug being needed to keep the animal asleep. Depending upon the premedication drug cocktail given, other specific effects may also be achieved including: reduction of saliva production and airway secretions (this reduces drooling and the risk that saliva and respiratory secretions may be inhaled into the lungs during surgery); improved blood pressure; airway dilation (making it easier to breathe) and so on.

General anaesthesia is normally achieved by giving the dog an intravenous injection of an anaesthetic drug, which is then followed up with and maintained using the same injectable drug or, more commonly, an anaesthetic inhalational gas. The female dog has a tube inserted down its throat during the surgery to help it to breathe better; to stop it from inhaling any saliva or vomitus and to facilitate the administration of any anaesthetic gases.

The skin over the animal's belly is shaved and scrubbed with an antiseptic solution prior to surgery.


Image: This is a picture of a cat's belly being scrubbed and cleaned with an antiseptic scrub in preparation for cat spay surgery. A bitch being prepared for dog spaying surgery would have her belly scrubbed in a similar fashion.


The surgery:
In order for you to properly understand the process of dog spaying surgery, I have to take a second to explain the anatomy of the female dog's reproductive organs.


Image: This is a diagram of the reproductive anatomy of a female dog as it appears when the abdomen is incised and entered from the abdominal midline. I have not drawn in the canine intestines or bladder (aside from the stump of the bladder neck - bottom), which would normally overlie the animal's reproductive structures when the animal is positioned on its back (the reproductive organs occupy the roof of the abdomen, near the animal's spine and kidneys).

Of particular importance, when it comes to canine spay surgery, are the fatty ovarian pedicles (the tubes of dense fat and connective tissue containing the ovarian arteries and veins) and the uterine body, just ahead of the animal's cervix. These are highly vascular sites that must be tied off securely with sutures (so that they do not bleed) and cut in order for the uterus and ovaries to be removed.

In the female dog, unlike the female cat, the ovaries are held down firmly into the abdominal cavity by tight bands of ligamentous tissue, called the right and left suspensory ligaments (these are indicated in the above image). In order for the veterinary surgeon to safely access and tie-off the dog's ovarian pedicles, these suspensory ligaments must firstly be broken to allow the ovaries to be raised up out of the abdomen and into view. Breaking these ligaments can be difficult in dogs, particularly large dogs, adding to the risk of ovarian pedicle tearing and hemorrhage in this species (compared to the cat, where such risks are much lower). This risk of hemorrhage is made much greater when in heat or pregnant dogs are spayed (their ovarian pedicle vessels are bigger and more fragile) or when very obese, large breed dogs are spayed (their ovarian pedicles are imbedded in thick fat making them difficult to visualise even when the suspensory ligaments are broken correctly).



Image: This is a diagram of the reproductive anatomy of a female dog as it appears from the side. I have drawn this view in order to give you a three-dimensional idea of where the uterus sits in the dog (it is located very high within the abdomen). This is the anatomy that would be encountered if the veterinarian performed a flank spay (a spay technique whereby the veterinarian enters the animal's abdominal cavity via an incision made through the muscles of the animal's flank). I have not drawn in the intestines or colon (aside from the stump of the colon/rectum), which would take up most of the anterior blue space indicated in this diagram.

Of particular importance, when it comes to canine spay surgery, are the fatty ovarian pedicles (the tubes of dense fat and connective tissue containing the ovarian arteries and veins) and the uterine body, just ahead of the animal's cervix. These are highly vascular sites that must be tied off securely with sutures (so that they do not bleed) and cut in order for the uterus and ovaries to be removed.

In the female dog, unlike the female cat, the ovaries are secured firmly into place within the dorsal (upper) abdominal cavity by tight bands of ligamentous tissue, called the right and left suspensory ligaments (these are indicated in the above image). In order for the veterinary surgeon to safely access and tie-off the dog's ovarian pedicles, these suspensory ligaments must firstly be broken to allow the ovaries to be raised up out of the abdomen and into view. Breaking these ligaments can be difficult in dogs, particularly big dogs, adding to the risk of ovarian pedicle tearing and hemorrhage in this species (compared to the cat, where such risks are much lower). This risk of hemorrhage is made much greater when in heat or pregnant dogs are spayed (their ovarian pedicle vessels are bigger and more fragile) or when very obese, large breed dogs are spayed (their ovarian pedicles are imbedded in thick fat, making them difficult to visualise, even when the suspensory ligaments are broken correctly).



DOG SPAYING PROCEDURE STEP 4:
The skin is incised and the dog's abdomen entered.


Photograph 1: This is a picture of a small incision line being made in the skin of a young cat being spayed. You'll notice that the incision line is very small (approx 1 cm long) and that it is being made approximately 1 inch below the animal's umbilical scar on the abdominal midline. In dog spaying surgery, however, the skin incision line is generally a lot longer than in the cat (anywhere from 2-6cm or more, depending on the size of the dog) and it is generally started further forwards on the abdominal midline, right behind the dog's umbilical scar.

Picture 2: In this image, the veterinary surgeon is removing some of the fat (termed subcutaneous fat, sub-q fat or SC fat) from the incision line region. The fat is the white, shiny substance in the center of the incision line. There is generally a lot of fat located between the animal's (cat or dog) skin and its abdominal wall muscles. The veterinarian will often cut a small amount of this fat away, allowing easy access to and visualisation of the cat or dog's abdominal wall muscles.



Image 1: The veterinarian enters the cat or dog's abdominal cavity by cutting through the abdominal wall musculature on the midline of the abdomen. The veterinarian aims to cut along a central line of scar tissue that joins the right and left sides of the animal's abdominal wall musculature. This line of scar tissue is called the linea alba (literally meaning - "white line"). By cutting through scar tissue, rather than the red muscle located either side of the linea alba, the veterinarian reduces the amount of bleeding incurred in entering the pet's abdominal cavity.

Photograph 2: This is a close-up picture of the incision line after the linea alba has been incised. You can see the hole going into the abdominal cavity.

Photo 3 (right): This is a post-mortem image of a cat's abdominal wall muscles (the image would be the same if the animal were a dog). The skin has been removed and the linea alba (white line - indicated with arrows) is clearly visible.



DOG SPAYING PROCEDURE STEP 5:
The ovarian pedicles and uterine body are ligated (tied off) and cut and the uterus and ovaries are removed from the abdomen.

Image: This is the same diagram that I presented earlier, showing the reproductive anatomy of the female dog. In this diagram, the sections of the reproductive anatomy that are ligated (tied closed with sutures) and incised (cut through) are indicated with green lines. This tying-off and cutting procedure needs to be performed with great care, otherwise there is the risk of severe internal bleeding occurring or a section of ovary being left behind (ovarian remnant), which could result in the animal returning to heat (showing signs of heat) after it has been 'desexed'.

Author's note: In the case of dog spaying surgery, the right and left suspensory ligaments are very important. These ligaments need to be broken in order for the canine ovarian pedicles (ovarian arteries and veins) and ovaries to be accessed, ligated and transected (cut).

Image: This is the same diagram that I presented earlier, showing the reproductive anatomy of the female dog when taken from a side-on (lateral) vantage point. In this diagram, the sections of the reproductive anatomy that are ligated (tied closed with sutures) and incised (cut through) are indicated with orange lines. This procedure needs to be done with great care otherwise there is the risk of severe internal hemorrhage occurring or a section of ovary being left behind (ovarian remnant), which could result in the animal returning to season (showing signs of heat) even though it has been 'desexed'.



SPAYING A DOG PROCEDURE STEP 6:
The dog's abdominal wall is sutured closed.


Pictures: After the uterus and ovaries have been removed, the surgeon uses absorbable suture material to close the hole in the dog's abdominal wall musculature (linea alba). Because the linea alba is essentially a tendon-like, collagenous structure (made of collagen), it has less blood supply than red muscle and, therefore, takes longer to heal than muscle would. To take this slower healing into account, the veterinarian often uses a longer-lasting suture (a suture that is slower to lose its strength and slower to absorb) to close the linea alba. Because this suture absorbs over time, the vet does not have to remove it later on.



Image:The linea alba has been sutured closed.



DOG SPAYING PROCEDURE STEP 7:
The subcutaneous fat layer is sutured closed.


Photo: The subcutaneous fat layer (also called the SC or sub-q layer) is sutured closed. This layer closure acts to reduce the amount of open space (called 'dead space') located between the animal's abdominal wall and skin layers, thereby reducing the risk of a large, fluid-filled swelling (called a seroma) forming at the surgery site. Basically, whatever space/gap you leave in a surgery site, fluid will pool in - by closing down this open space (dead space), the vet surgeon essentially leaves fewer sites available for inflammatory fluids to pool in.



SPAYING FEMALE DOGS PROCEDURE STEP 8:
The skin layer is sutured closed.


Images: The surgeon is closing the skin using non-absorbable skin sutures. These will need to be removed in 10-14 days.



Image: Absorbable skin sutures can also be placed. These are called intradermal sutures and they do not need to be removed. They look like a line with no suture material showing. They are useful because dogs find it harder to chew them out. These skin sutures are particularly useful when closing the skin incisions of aggressive dogs or dogs on remote properties because there is no need for the dog to return to the clinic to have the sutures out.


A Photographic Guide to Cat Spay Surgery:
If you would like to view a complete, step-by-step, photographic guide to feline desexing surgery, please visit our great Cat Spay Procedure page. Although it is not a dog spaying page per se, it should give you some idea of the process involved in performing a dog spay surgery since the two spay procedures are almost identical to each other.


A Photographic Guide to Spaying a Pregnant Cat:
As will be discussed in the FAQs and Myths section (section 8), it is possible to desex a female dog or cat who is already pregnant. What should be understood, however, is that the desexing of pregnant animals carries with it a much higher risk than the desexing of non-pregnant females does (the ovarian and uterine blood vessels are much larger and bleed a lot more and the uterus itself is greatly enlarged and much more friable and prone to tearing apart, compared to the non-pregnant uterus). In viewing this page (which does contain images of surgical abortion) what should be clear to you is that there is added danger and risk and pain (a bigger surgical incision) to the female animal in desexing her whilst she is pregnant and that, for this reason, the emphasis should be placed on having a female dog or cat desexed well before she manages to become pregnant. If you would like to view a complete, step-by-step, photographic guide to pregnant cat spaying surgery (which is, again, similar to pregnant dog spaying surgery), please visit our informative Spaying a Pregnant Cat page.

5. Dog Spaying After Care - all you need to know about caring for your female dog after dog spaying surgery.

When your dog goes home after dog spay surgery, there are some basic exercise, feeding, bathing, pain relief and wound care considerations that should be taken into account to improve your pet's healing, health and comfort levels.

1) Feeding your dog immediately after dog spaying surgery:
After a dog or puppy has been spayed, it is not normally necessary for you to implement any special dietary changes. You can generally go on feeding your pet what it has always eaten. Some owners, however, like to feed their pets bland diets (e.g. boiled, fat-free, skinless chicken and rice diet or a commercial prescription intestinal diet such as Royal Canin Digestive or Hills i/d) for a few days after surgery in case the surgery and anaesthesia process has upset their tummies. This is not normally required, but it is perfectly fine to do.

Unless your veterinarian says otherwise, it is normally fine to feed your dog the night after surgery. Offer your pet a smaller meal than normal in case your pet has an upset tummy from surgery and do not be worried if your pet won't eat the night after surgery. It is not uncommon for pets to be sore and sorry after surgery and to refuse to eat that evening.

If your dog is a bit sooky and won't eat because of surgery-site pain, feel free to tempt her with tasty, strong-smelling foods to get her to eat. Warmed skin-free roast chicken often works well and it is not too heavy on the stomach. Avoid fatty foods such as mince, lamb, pork and processed meats (salami, sausages, bacon) because these may cause digestive upsets.

Be aware of your pet's medications and whether they need to be given with food. Some dogs go home on non-steroidal anti-inflammatory drugs (NSAIDs) such as Carprofen (trade names include: Prolet, Rimadyl, Carprofen tablets), Firocoxib (tradenames include Previcox) and Meloxicam (tradenames include Metacam) after surgery. These drugs (with the exception of Previcox) need to be given with food. Do not give these drugs if your dog is refusing to eat.

Most dogs that get spayed are not normally off their food for more than a day. You should contact your vet if your pet does not eat for more than 24 hours after surgery.


2) Exercising your dog after dog spaying:
It takes 10-14 days for skin wounds to heal after surgery; even longer for the linea alba wounds to heal. It is therefore recommended that running-around exercise be avoided or minimized for a minimum of 2 weeks after surgery to allow the skin the best chance of staying still and healing. Restricting your dog's exercise will also reduce the risk of a large seroma forming (section 6b) and reduce post-operative spay-site pain.

Of course, many of you scoff at the idea of "keeping a puppy rested and still!" It is, therefore, normally fine if your puppy romps around quietly inside your house and performs its normal, quiet indoor activities and play (no running around madly and jumping on and off couches, of course!). I would, however, avoid letting your dog go outside off-lead until she has had time to heal (14 days minimum). This is especially important if the pup is of the energetic, boisterous kind (in contrast, an old, quiet dog more fond of sleeping in the shade might be fine to allow outside). Keeping the animal indoors or in a non-dirty confined space (e.g. a small dog run) will prevent excessive exercise, which could impede healing, and it will also prevent the canine spay wounds from becoming wet or packed with mud and dirt (and thus infected). In addition to this, keeping your dog inside will also ensure that she doesn't wander off and go missing for days on end. At least if she is kept inside, you will be able to find her and check on her progress and well-being daily.


3) Wound care after dog spaying surgery:
Normally you do not have to do anything special with your pet's surgical desexing wounds (e.g washing and bathing them) after surgery. The most important thing you do need to do is monitor the wound to ensure that it remains looking healthy and clean.

Check the abdominal suture line daily. Look out for any signs of redness, swelling and wound pain (surgical wounds should not normally appear painful or red beyond the first 3-5 days after surgery). Look out for obvious signs of infection (e.g. a yellow or green pussy discharge) or signs that the wound is breaking down (the wound will split and contain cheese-like white or yellow necrotic tissue inside it if it is breaking down). If you see any of these signs, take the pet to your vet for a check up.

If the wound site gets dirty (e.g. covered in mud or faeces), you can clean it with warm salty water, saline (0.9% NaCl) or a very dilute betadine solution (betadine solution in water made up to a weak-tea colour concentration) to remove the contamination. The wound and sutures should then be dried thoroughly to stop bacteria from wicking deep into the surgical site. The cleaned wound should then be closely monitored over the next few days because wounds soiled in dirt or faeces are at high risk of becoming infected, even if they are bathed.

Do not let your pet lick its spay wounds! This is a major cause of surgery wound breakdown - the pet licks the wounds and introduces mouth-bacteria into the wounds, making them wet and infected and unable to heal. In severe cases, the pet actually pulls out the sutures with its teeth resulting in the wound breaking apart completely.

At the very first sign of wound licking, go to your vet immediately and get an Elizabethan collar (E collar) for the dog. The collar will stop the pet from tampering with the stitches and hopefully prevent wound break down and infection. If the dog starts licking in the middle of the night and you can not get an E collar, you can cut the circular bottom out of an appropriately-sized, clean plastic flower pot (leave the drainage holes intact); place this over your pet's head and neck like an Elizabethan collar and thread the pet's collar or a stocking through the pot-plant drainage holes to secure it to your pet's neck. Be careful to place it so that your dog can not choke and go and get a proper E collar from your vet in the morning.

Wound licking can also be reduced by putting bitter apple spray, methyl phthalate solution or another commercial bitterant solution onto the pet's suture line. Wound-Gard is one commercial product that serves this role (there are many other products that serve a similar function).


Images: If your dog's spay wound looks like either of these, see a vet immediately. The first image is spay site that has broken down because the animal (a cat) has pulled its skin sutures out. The second image is an emergency - all of the sutures, including the abdominal wall sutures, have broken down and the pet's innards and intestines are sticking out! This needs urgent surgery.


4) Bathing or washing your dog after a dog spaying operation:
Because it takes 10-14 days for sutured (stitched) skin wounds to heal and seal closed, it is advised that the animal not be bathed or allowed to go swimming for the first 14 days after surgery. Wetting the sutures before this time may allow bacteria to enter the surgery site and set up an infection which could result in wound breakdown and abscess formation (bacteria are carried deep into the skin by the wicking capillary action of water traveling along the sutures).


5) Suture removal after dog spaying surgery:
If your dog had superficial, non-absorbable skin sutures placed in its skin to close its canine desexing wound, then these will need to be removed once the incision line has healed. Sutures are normally removed 10-14 days after surgery. They can be removed at home, but ideally they should be removed by a veterinarian (the vet can determine if the wounds have healed up enough before removing them). Vet clinics do not normally charge a fee for suture removal.


6) Pain relief after dog spaying:
In my experience, most dogs do not seem to show all that much pain after dog spaying surgery. Many dogs start playing and running around and demanding to "play ball" or "go walkies" the very same night! If your pet is in pain, however, there are ways that you can help.

Go to your vet for some analgesic pills or drops. Most vets send their neutering patients (especially dog spays) home with a few days of pain relief as a matter of course, however, some vet clinics do not. If you haven't been sent home with any pain relief for your dog and your pet shows signs of pain after dog spaying surgery, you can return to your vet clinic and request pain relief pills. If your pet is very old or it has compromised kidney or liver function, certain pain medications may not be recommended and other pain relief solutions may need to be found.

DO NOT self-medicate your pet with human pain-killers. Many human pain relief drugs can be toxic to dogs.
Keep your dog confined and quiet and indoors. Pets that are allowed to run around after surgery are more likely to traumatize and move their sutures, leading to swelling and pain of the surgical site. Reducing activity means less pain.

Consider placing hot and cold compresses on your pet's surgical site to reduce pain and swelling. Placing a dried-off ice pack wrapped in a tea towel (never put ice directly against the skin) on the pet's surgery site for 10 minutes and then placing a hot water bottle (also wrapped in a tea towel) on the site for another 10 minutes and then replacing the cold pack and so on (i.e. alternating hot and cold packs for about 30-45 minutes) can go a ways towards reducing surgery site pain and swelling.
CAUTION - Only do this if you have a very nice tempered dog - remember that pets in pain can snap and bite and you may well upset the animal more by handling her wound, even though you are only trying to help her. Do not push the issue if she gets grumpy. Leave her alone.


7) Monitor your dog's general demeanor and well-being after dog spaying surgery:
Your dog should be back to normal within 1-3 days after surgery. She should be eating, drinking, urinating, defecating and wanting to play and interact just as much as she did prior to the surgery. If your pet is depressed; not eating; not drinking; drinking excessively; not defecating; defecating black, tarry stools; not urinating and/or shows any signs of vomiting a few days after surgery, this is not normal. You need to take your pet to a vet clinic immediately.







6. Post Spay Complications - Possible surgical and post-surgical (post-op) complications and side effects of spaying a dog.

There are some surgical and post surgical complications of desexing a female dog that should be considered before you take the step of having your dog spayed. These are outlined below. The most important thing to remember about the complications listed below is that the vast majority of these complications are very rare and the small risk of them occurring should not outweigh the benefits of having your dog spayed. Of those complications that are more common (the common ones are indicated), the vast majority of these are not life-threatening and most can be prevented by good attention to after-care and wound care.

6a. Pain after surgery (common).
It is not uncommon for female dogs to show signs of mild to moderate discomfort and pain immediately after having a dog spaying surgery. This is particularly the case if the veterinarian has had to make a large incision into the dog's abdomen to remove an in-heat or pregnant uterus (pregnant uteruses, in particular, can be very large, often needing a large incision to facilitate their removal).

Dogs that are in discomfort after desexing will normally show signs and symptoms suggestive of pain in the abdominal region. The animal may pant; refuse to settle; adopt a stiff-legged gait (animals with sore bellies are reluctant to move their hind-legs much when walking and so will tend to walk stiffly) and refuse to sit down in a normal sitting posture. Some dogs (especially small and toy breeds) will tremble and shiver. It is not uncommon for painful dogs to hide under beds and seek solitude in dark places and want to be alone. They will often growl aggressively when approached and may even squeal and yelp and snap and bite when touched and handled by their owners. Some female dogs will be irritated by the skin sutures and/or by the fact that the delicate belly skin was shaved (and thus abraded a little) and keep licking the region obsessively (this licking needs to be discouraged by placing an Elizabethan Collar on the dog or a bitterant on the wound - see section 5 on after-care). Some dogs will even bite and pull at the stitches (this also must be discouraged). Some female dogs will even go off their food a bit for a few days after desexing because of the discomfort.

If your pet is in pain, you can return to your veterinary clinic for some analgesic (pain killer) pills. Most vets send their dog spay patients home with a few days of pain relief as a matter of course, however, some vet clinics do not. If you haven't been sent home with any pain relief for your dog and your pet shows signs of pain after surgery, you can return to your vet clinic and request pain relief pills - these will normally be enough to keep your pet comfortable. If your pet is very old or it has compromised kidney or liver function, certain pain medications may not be recommended and other pain relief solutions may need to be found.

Keep your pet confined and quiet and indoors if it is in pain. Pets that are allowed to run around after surgery are more likely to traumatize and move their sutures, leading to swelling and pain of the surgical site and increased risk of seroma (next point) formation. Reducing activity means less pain. Keeping the dog indoors will also allow you to keep an eye on it, as painful dogs allowed outside will often take refuge in dark, quiet places (e.g. under the house) and not come out for a few days, which can be very worrying for the owner.

Consider placing hot and cold compresses (nothing that will wet the site however) on your pet's surgical site to reduce pain and swelling. Placing an ice pack wrapped in a tea towel (never put ice directly against the skin) on the pet's surgery site for 10 minutes and then placing a hot water bottle (also wrapped in a tea towel) on the site for another 10 minutes and then replacing the cold pack and so on (i.e. alternating hot and cold packs) can go a ways towards reducing surgery site pain. Do this for around 30-45 minutes.
WARNING - Only do this if you have a very nice tempered dog - remember that pets in pain can bite and you may well upset the animal more by handling her wound, even though you are only trying to help her.

If the belly skin appears very abraded and red to you (either from clipper rash during pre-surgical shaving of fur or due to your pet's licking), you should speak to your vet about it. He may prescribe some cream containing a steroidal anti-inflammatory drug, an antibiotic compound and a local anaesthetic compound (e.g. tradenames include Ilium Neocort Cream, Neotopic Cream) to apply to the abraded regions to soothe them. Do not apply the cream directly to the surgical incision line though as it could impede healing.

If your pet's discomfort lasts more than about 1-3 days after surgery, you should seek advice from your vet. Most dogs don't show signs of surgical discomfort beyond about 3 days and pain persisting beyond this point may be a sign of wound infection, suture-line reaction or some other issue.

IMPORTANT SAFETY TIP - be very careful when handling sore dogs immediately after surgery. Even the nicest dog will snap and bite if you handle it in a painful region. If the dog starts lunging, growling, snorting or snapping, keep away.


6b. A large 'lump' or 'swelling' at the dog spay operation site (frequent).
It is not uncommon for some recently desexed dogs to develop a medium to large skin swelling at the site of the skin sutures (a large bulge, lump or bump at the surgery site). These swellings can be a number of things, the most common being: seromas (fluid-filled pouches), hernias, infections/abscesses, inflammatory swellings, scar tissue thickenings and subcutaneous or linea alba stitches. Which swelling your dog has really depends on you seeing a veterinarian and getting a diagnosis - you should not attempt to diagnose your dog's surgical site swelling at home.

Seromas:
A seroma is a large lump that forms at a surgical site (particularly a ventrally-located or gravity 'dependent' site like the middle of a dog's tummy) when a space or gap is left open in the subcutaneous fat layer (i.e. a gap in the fatty layer located between the skin and the abdominal wall muscles). This gap (also called dead space) occurs either as a direct result of the surgical process (failure to close the region enough) or it is caused by the animal traumatising the surgery site post-operatively through licking or excess exercise. Straw- to red-coloured inflammatory fluids (fluids that leak into any surgically-traumatised area as part of the natural healing process) pool in these subcutaneous gaps, producing a bulge underneath the suture line. This bulge is full of watery inflammatory fluid and is termed a seroma.

Seromas generally occur if the veterinary surgeon leaves too much of a gap (called 'dead space') open in the fatty layer that exists between the dog's abdominal wall muscles and its skin. In describing the surgical process of dog spaying surgery (section 4), I emphasized STEP 7 (suturing the subcutaneous fat layer closed) - this step is important in preventing seromas from occurring. From a post-operative perspective, seromas may also occur on the owner's watch, if a pet is allowed to run around too much (excessive exercise and rough-and-tumble) or lick its surgery site excessively in the hours to days after surgery.

Diagnosis of the condition can be made by sticking a needle into the lump - the vet will typically draw out a straw to pink/red-colored fluid. If pus comes out instead then an abscess, rather than a seroma, may be the diagnosis. Diagnosis can also be made by placing an ultrasound probe on the lump - seromas look like giant, black, fluid-filled spaces or, alternatively, black spaces interlaced with fine white threads (almost a honeycomb or lacy appearance - see image below) on ultrasound. Ultrasound is very useful when determining whether a belly bulge is a seroma or a hernia.

Generally, fluid-filled, seroma sacs will resolve and shrink on their own as the fluid is reabsorbed back into the animal's body. They do not normally require any specific treatment. You can manage any discomfort by giving the dog canine pain killers, restricting its exercise, preventing licking and placing cold compresses on the lump. In severe cases, your vet may insert a needle into the swollen sac to remove some of the fluid and relieve some of the pressure and pain, however, this is seldom necessary, rarely works for long (the fluid often refills in time) and does run the risk of introducing bacteria into a sterile, protein-filled site and setting up an abscess. Owners very worried about seroma appearances can elect to have their dog reoperated on and the seroma surgically drained and closed (again this is seldom needed).


Picture: This is the appearance of a large seroma on ultrasound. Seromas are fluid-filled spaces (the black pockets are the fluid) interlaced with connective tissue, fat and fibrin (the fine, white, lacy lines criss-crossing the black pockets).

Hernias:
A hernia is a lump that forms under the skin when the animal's abdominal wall sutures break down, allowing intestines and fat and other internal organs to exit the abdominal cavity and migrate into the space under the skin. Hernias can be very small and inconsequential if only abdominal fat migrates out or they can be very large and life-threatening, particularly if organs like the bowel or bladder find their way out through the hole and become strangulated.

If only fat migrates out through the hernia ring, then the animal will often show no other signs aside from the lump located under its skin. This lump will usually be non-painful to touch and palpate and it will often seem to come and go (disappear and reappear) as the fat slips back and forth between the abdominal cavity and the subcutaneous space.

If one of the internal organs (usually a loop of intestine, but occasionally the bladder or even the spleen) migrates out through the hole, then the consequences may either be very trivial or very severe depending on the situation. If the hole in the abdominal wall is quite large (see the cat images below) and the organs are able to freely slip back and forth between the abdomen and the subcutaneous region, then the animal will usually show few symptoms apart from the lump (often large) under its skin. In such a situation, this lump will normally be non-painful and soft-feeling to touch and palpate and it will often seem to come and go (disappear and reappear) as the organs slip back and forth between the abdominal cavity and the subcutaneous space. The veterinarian will often be able to push the organs back into the belly cavity (termed reducing the hernia - see image 3 below) with ease.

If, instead, internal organs come out through the hole in the abdominal wall and become trapped (e.g. the intestines may swell after exiting the hernia hole and become entrapped or the bladder may slide out, fill up with urine, and become trapped) then the situation will rapidly become more serious. The animal will often present with significant pain: restlessness, crying, panting and licking/biting at the hernia-site. The hernia site itself will often be very swollen, very painful, very firm to the touch and, in severe cases, it may even be red or black in colour. The veterinarian will often be unable to reduce the organs back into the animal's abdominal cavity because of the swollen state of the organs inside the hernia and because of the pain to the animal. In the case of a trapped intestine, the animal will often show additional symptoms typical of an intestinal obstruction: vomiting, dehydration, inappetence or anorexia, failure to pass stools and so on. In the case of a trapped bladder, the animal will often show additional symptoms typical of bladder obstruction: abdominal pain, straining to urinate, failure to pass urine, crying when trying to urinate, vomiting, listlessness, inappetence. If the condition is not resolved immediately through supportive care and surgery, the trapped organ can begin to rot and the animal will become very sick and shocky. Life-threatening peritonitis can occur if the bowel rots and ruptures, releasing bacteria into the abdominal cavity. Death can occur.

Hernias generally occur if the veterinary surgeon uses the wrong suture material to close the linea alba line or if he does not close the suture line correctly. In describing the surgical process of dog spaying (section 4), I emphasized STEP 6 (suturing the linea alba closed) - this step and the use of slow-absorbing suture material is important in preventing hernias from occurring. From a post-operative perspective, hernias may also occur on the owner's watch, if a dog is allowed to run around too much (excessive exercise and rough-and-tumble) in the hours to days after surgery. It is the main reason why we emphasise not exercising the animal for 14 days minimum after surgery.

Diagnosis of the condition can be made by placing an ultrasound probe on the lump - the hole in the abdominal wall muscles can often be seen on ultrasound as can the organs coming through the space. Palpation of the lump can also give the vet a clue - if the vet can reduce the lump back into the animal's abdomen (image 3), then the lump is a hernia (seromas can not be reduced). The vet may also be able to feel the defect (hole) in the animal's abdominal wall.

Treatment of the condition requires surgical repair: emergency surgical repair if a piece of bowel has become strangulated or if the bladder has come out through the hernial ring. Animals with strangulated bowels or trapped bladders are often very sick (they often need some of their bowel resected - cut away) and their prognosis should be considered guarded.


Image 1: This is a cat with a large umbilical hernia (see the lump hanging under the belly). This particular animal was not a post-surgical case - this cat was actually born with a hole in its abdominal wall muscles (i.e. a congenital hernia). The large lump formed because intestines and fat migrated from the cat's abdomen into the space under its skin. This cat was still bright and well because no bowel strangulation had occurred.

Image 2: When the cat was placed onto its back, the lump remained. The veterinarian could even grasp hold of the cat's herniated organs and feel that they were organs through the cat's skin. There was no pain reaction associated with grasping hold of the herniated intestines, which also suggested that these were not in any way strangulated.


Image 3: The veterinarian was able to reduce this cat's hernia easily. Once the hernia was reduced, the veterinarian was able to feel a large hole in the cat's abdominal wall (it was big enough to insert a finger through). The cat didn't care one bit.

Abscesses:
Abscesses are similar to seromas (i.e. a fluid-filled swelling under the skin, located between the skin and the abdominal wall muscles), except that, rather than being sterile, bacteria have gained access to the subcutaneous space and the cavity is filled with thick, cream-to-brown-coloured pus and bacteria, rather than clear straw-coloured or reddish seroma fluid. Unlike seromas, which are normally painless, abscess lumps are typically hot and painful to touch and the skin overlying them is often red, purple or black in colour. Animals with abscesses are often unwell, showing signs of surgical discomfort, lethargy, inappetence, fever (i.e. panting, they feel hot-to-touch) and an inability to settle (i.e. restlessness, hiding away in dark places). If left untreated, abscesses will often keep growing in size (seromas tend to stay a constant size) and eventually burst out through the suture-line or a hole elsewhere in the belly skin, resulting in wound breakdown.

Abscesses generally occur because bacteria have managed to gain access to the fatty layers beneath the skin suture line either during surgery or soon after surgery. They most commonly occur because the pet was allowed to lick the surgical wounds and, consequently, introduce mouth bacteria into the surgical incision line/s (bacteria travel down the wet sutures, deep under the skin). Infection also tends to occur if the sutured wounds are allowed to get wet (e.g. the animal was bathed, allowed to go swimming, allowed to lay in mud) or if the spay wounds are allowed to become soiled by faeces, urine or dirt. Wound infection may also occur if the vet performs the dog spay surgery on an animal with diseased allergic or infected belly skin. Bacterial numbers are very high in diseased, infected skin and will easily enter the wound site during surgery, regardless of the amount of pre-surgical prepping done.

Very occasionally, dog spay wound infection and abscessation may be the result of poor surgical technique (e.g. vets not wearing gloves to do surgery); poor skin preparation before surgery; a freak bug entering the surgical site (sometimes nasty bacteria like Golden Staph and flesh-eating Streptococcus and Mycobacteria species will find their way into a vet clinic and cause havoc) or the animal having a poor or compromised immune system. Animals with Cushing's disease, Diabetes Mellitus and other immune system suppressive disorders are more prone to wound infections and abscesses.

Diagnosis of the condition can be made by sticking a needle into the lump - the vet will draw out a thick, cellular, creamy to reddish-brown coloured fluid. Diagnosis can also be assisted by placing an ultrasound probe on the lump - abscesses look like grey fluid-filled spaces on ultrasound.

Unlike seromas, abscesses will not tend to resolve and shrink on their own. The animal will need to be seen by a vet and it will most likely require surgical drainage of the abscess and antibiotics to fix the problem.

Inflammatory swellings and scar tissue thickenings:
When a dog has a spay surgery (any surgery really), a lot of trauma is done to the tissues in the surgical site (after all, they have just been cut into). Such surgical trauma sets up a massive healing response by the body. Loads of inflammatory cells and collagen-making, scar-producing cells (termed fibroblasts) get called into the region to mop up the dead cells and debris left behind by the surgeon and repair the cut/defect that the surgeon has made in the tissues. This is normal tissue repair.

What's important to remember is that the calling in of all of these extra cells will produce a visible swelling at the surgical site. It is not uncommon or unexpected for a dog spay wound to feel thickened for several weeks after surgery as the healing and scarring process takes place. The inflammatory process shouldn't feel like a large lump per se, but there will be a non-painful, generalised thickening felt along the dog's suture line.

Over time, this thickening should subside and shrink somewhat as the inflammatory cells complete their tasks and leave, leaving only scar tissue behind. It is not uncommon, however, for this residual scar tissue to remain slightly bulky and for the owner to be able to feel the small knot of scar tissue under the dog's skin for the rest of its life. Don't worry. It's normal.

Subcutaneous or linea alba stitches:
This one is not a problem, but it does happen often enough that I'll mention it. Some of the internal sutures (especially linea alba sutures) that we use for dog spaying surgery are very long lasting and may take years to completely absorb and disappear. It is therefore not uncommon for owners of thin and thin-skinned dogs (I've seen a lot of whippets for this) to feel the sutures or suture knots underneath the animal's skin months to years after the spay surgery and to be concerned that these 'prickly spiky lumps' are abnormal. They're not - they're just the knots that you can feel.


6c. Wound break-down - partial or complete break down of the skin sutures or stitches (moderately common).
It is possible for the dog spay incision site to break down days to weeks after desexing, resulting in an open, rotten-looking, fleshy hole in the female dog's abdominal skin.

Wound break-down most commonly occurs because of poor home care. It tends to occur because the dog was permitted to lick the sutureline and/or pull its sutures out or because the animal was permitted to run around a lot at home (e.g. excessive exercise, dog allowed to roam freely outdoors). Excessive exercise places the sutures under constant motion, which can result in them falling apart prematurely. In some cases, the wound breaks down because of bacterial infection (wounds can not heal if they infected) and, again, this is often the result of poor home care, not poor surgical technique. Infection tends to occur most commonly if the sutures are allowed to get wet within the first 14 days of surgery (the animal is bathed, allowed to go swimming or allowed to lick the wound excessively) or if the sutures are allowed to become soiled by faeces, urine or dirt.

Very occasionally, wound break-down can be the result of poor surgical technique (e.g. the sutures were not placed correctly, irritant suture materials were used or the wrong suture materials were used); performing surgery on infected or diseased skin (animals should not be operated on if they have allergic, rashy or highly-infected skin) or removing the sutures too early (before the skin has had time to heal). Some cases of wound break-down may even be the end result of suture-site inflammatory reactions (see section 6e).

Author's note - wound breakdown will occasionally be seen when a heavily pregnant or lactating dog is operated on using a midline (belly) approach that goes between the two lines of canine mammary glands. In these animals, it can sometimes be very difficult for the vet surgeon to avoid lacerating the mammary glands of the animal during the first incision (the mammary tissues are huge and pretty much meet in the middle of the dog's belly). Cutting into these glands can result in milk leaking into the fatty tissues under the animal's skin. Milk is irritant and foreign to the subcutaneous tissues and the body will often react against it with an aggressive inflammatory foreign body reaction that can result in pain, swelling and even wound site break down.

Very rarely, wound breakdown may also be a sign that the animal in question has some form of healing disorder. Such disorders are uncommon, but do exist. For example, animals with Cushing's Disease (Hyperadrenocorticism) or diabetes are prone to slower-healing wounds and their sutures may need to be left in longer than usual (taking them out too early may result in wound break down). Animals with collagen disorders, inflammatory-cell-response disorders and other disorders affecting tissue healing function may also heal very poorly and thus be prone to wound break-down.

Wound breakdown is cause to see your vet. If the wound break down is only mild, the animal may only require antibiotic coverage; an Elizabethan collar and better home care to treat the problem. If the wound has completely fallen apart, the vet may need to operate on your pet again to retrim and repair the surgical wound. Healing will then take another full 10-14 days to occur.


Image 1: This first pic is a cat spay site that has broken down because the cat pulled its skin sutures out. This will need to be seen by a veterinarian. It is most likely that this wound will need to be trimmed up and restitched.

Image 2: This second image is a true emergency. All of the sutures, including the abdominal wall sutures, have been pulled out by the cat and the cat's intestines are sticking out! This needs urgent surgery. If confronted with something like this, you should cover the pet's hernia in a moist (saline is best, but clean water is fine) gauze pad, clean cloth or paper towel (kitchen roll) and get it to a vet ASAP. Do not attempt to push the intestines back into the animal - if they are dirty, you will be pushing that dirt back into the abdomen. Just keep the organs moist and covered and get to the vet. Do not neglect to get the animal (cat or dog) to the vet as the herniated tissue will dry out and die, get dirty or track bacteria into the animal's abdomen, resulting in peritonitis. In some cases, the cat or dog will even eat its own intestines (yes - they will do such things), which would be a disaster.


6d. Wound infection.
The causes of wound infection bear many similarities to those mentioned in section 6c and infection of surgical incision-sites can often lead to secondary wound break-down.

Wound infection occurs when bacterial organisms gain access to the surgical incision site and multiply there in large numbers. The bacterial invasion causes damage to the body tissues at the site of infection (this limits the healing of tissues in the spay site) and triggers a secondary immune system attack on the infected region, resulting in inflammation (redness, swelling, heat) and a build up of pus (invading white blood cells produce yellow, green or red-brown discharges) in the area.

Owners often first notice infection when the dog spay incision line becomes sore, swollen, red and hot-to-touch. Sometimes, the pet will tell the owner that it is in pain by licking the infected regions obsessively: infection should certainly be suspected if a pet goes from initially not being bothered by its wounds to licking and biting at them excessively. Within hours to days of this redness and inflammation being noticed, the owner may witness a yellow to green purulent discharge (pus) coming from the suture holes or the incision line itself. If allowed the progress, the wound may split apart completely, resulting in wound breakdown. Sometimes, if the skin incision site has sealed over but the infection has gained access to the deeper subcutaneous fatty tissues, pus and infection will build up underneath the skin producing a painful pus-filled swelling called an abscess. When the abscess bursts, large amounts of pus will drain out of the area.

Wound infection is very uncommon in most routine desexing surgeries and most commonly occurs because of poor home care. It tends to occur because the dog was allowed to lick the sutureline and, consequently, introduce mouth bacteria into the surgical incision. Infection also tends to occur if the sutures are allowed to get wet (the animal was bathed, allowed to go swimming, allowed to lay in mud) or if the sutures are allowed to become soiled by faeces, urine or dirt. Wound infection may also occur if the vet performs the surgery on an animal with diseased allergic or infected belly skin. Bacterial numbers are very high in diseased skin and will easily enter the wound site during surgery, regardless of the amount of pre-surgical prepping done.

Very occasionally, wound infection may also be a result of poor surgical technique (e.g. vets not wearing gloves to do surgery); poor skin preparation technique before surgery; a freak bug entering the surgical site (sometimes nasty bacteria like Golden Staph and flesh-eating Streptococcus and Mycobacteria species will find their way into a vet clinic and cause havoc) or the animal having a poor or compromised immune system. Animals with Cushing's disease, Diabetes Mellitus and other immune suppressive disorders may be more prone to wound infections.

Wound infection is definitely cause to see your vet. If the wound infection is only mild, the animal may only require antibiotic coverage; an Elizabethan collar and better home care to treat the problem. If the wound has completely abscessated and is at risk of falling apart, the vet may need to operate on your pet again to retrim and repair and clean the surgical wound. Healing will then take another full 10-14 days to occur.


6e. Suture-site reactions - swollen, red skin around stitches (uncommon).
Suture site reactions refer to allergic-type, inflammatory skin reactions that some dogs and other animals develop because of the type of suture being used in the surgical incision repair. Basically, suture site reactions are immune-mediated inflammatory reactions that occur when the dog's body decides to reject the foreign bodies (the sutures or stitches) that the vet has just implanted into the skin. True suture site reactions are not that common (modern day sutures are normally very inert and non-reactive) and most so-called suture site reactions are actually wound infections or break-downs caused by all of the factors mentioned in sections 6c and 6d.

When suture site reactions do occur, what tends to happen is that the dog develops signs of inflammation (redness, swelling, heat, maybe even a serous (watery) or pussy discharge) around the suture holes themselves, but not along the surgical incision line in general.
i.e. The reaction is centred around the sutures, but the rest of the surgery site appears fine.

Author's note - early bacterial infections can mimic suture-line reactions if the bacteria have gained access to the body tissues by traveling up the sutures. In these cases, the inflammatory reaction will also be centred around the sutures because this is where the bugs are lurking. Untreated, however, such bacterial infections will usually spread and become more generalized (i.e. involve all of the incision line), whereas true suture-line reactions should remain localized and focussed upon the stitches.

Usually what happens with true suture site reactions is that the wound incision itself heals up fine because the reaction is centred around the sutures only. Once the sutures are removed (usually after the surgical site has healed), the problem usually resolves on its own. If the condition is severe and the wound healing itself is becoming secondarily compromised by the suture reaction, the vet may elect to remove the skin sutures early to let everything settle down again and heal. This does, however, pose a risk of the main wound breaking down prematurely. In most cases, especially mild cases, the vet will elect to leave in the sutures until the main wound has healed and then remove the sutures to let the suture reaction resolve.

To prevent the problem in the future, a different type of suture material should be selected for that animal.


6f. Excessive wound hemorrhage - excessive bleeding during or after dog spaying surgery (rare).
It is very uncommon to see a pet dog bleed excessively from its incision site following a routine dog spaying surgery. Spay sites, particularly the spay sites of dogs desexed whilst late-pregnant or lactating (these animals have huge blood vessels in their skin) will sometimes ooze or weep a bit of bloody fluid (an occasional drop here and there) a hour or so after surgery, but they do not normally pour blood.

Excessive bleeding of dog spaying sites may be a sign that the veterinarian has not performed the desexing surgery properly (e.g. the vet has lacerated the spleen or major blood vessel inside of the dog or not tied off one of the ovarian or uterine blood vessel stumps properly), however, in these kinds of situations, the vet is usually aware of the mistake having been made at the time of surgery and will have taken steps to repair it prior to waking the dog up. More commonly, excessive bleeding from the surgical desexing site/s is an indication that the pet has some kind of significant blood clotting disorder including: hemophilia, rodent poison ingestion, vwD (von Willebrand disease) or a blood platelet deficiency problem (i.e. thrombocytopenia, ITP).

If excessive bleeding from the surgical desexing site is observed, the dog needs to immediately go back to the vet or (if it is after hours) to the nearest veterinary emergency center for treatment and work-up. This is particularly so if the animal seems weak or looks at all pale or white in the gums (pale or white gum colour is often a sign of severe blood loss and shock setting in). Animals with severe bleeding may require a blood transfusion and supportive care (perhaps even an exploratory surgery to find a ruptured blood vessel) to save their lives.


6g. Failure to ligate (tie off) the ovarian or uterine blood vessels adequately (rare).
This is the diagram picture presented earlier, which shows the reproductive and vascular anatomy of the entire female dog.



What you will notice from this diagram is that there are large arteries and veins supplying each of the animal's ovaries (these are called the ovarian arteries and ovarian veins) and that there are other large arteries and veins supplying each side of the animal's uterine body and each of the uterine horns (these are termed the uterine arteries and veins). These arteries and veins arise directly from the animal's aorta and vena cava respectively. The aorta and vena cava are the major blood vessels in the animal's body (in the dog they are about the width of a pencil and sometimes more - pretty huge vessels). You can imagine that, because these ovarian and uterine vessels arise directly from the aorta and vena cava, a fair bit of blood pressure and blood volume must flow through the blood vessels supplying the animal's uterus and ovaries.

This high uterine and ovarian blood flow is important to understand because it has a bearing on what can happen to the female dog if the ovarian pedicle vessels (ovarian artery and vein) or the uterine body vessels aren't ligated properly by the vet or if they manage to tear apart before the vet has had a chance to ligate them properly. If this occurs, the cut and bleeding ends of the ovarian or uterine blood vessels will not remain neatly within the surgical field and easily accessible. They will, instead, retract and spring back deep into the dog's abdominal cavity, close to their aorta and vena cava origins near the kidneys (in the case of the ovarian vessels) or colon (in the case of the uterine vessels) and begin to hemorrhage out there, resulting in the animal rapidly developing a belly full of blood.

The vet will need to extend his incision line into the animal's abdominal cavity (i.e. make the spay incision line longer to allow better visualisation) if he is to find the bleeding vessel, tie it off and thus save the animal. If the vet fails to find the vessel and tie it off, the animal could die from excessive blood loss. Even if the vet does find the bleeder in time, animals with severe ovarian or uterine artery hemorrhage may require a blood transfusion and further supportive care to save their lives.

Important author's note: it is important to emphasise that failure to ligate the ovarian or uterine vessels adequately during a dog spaying procedure is extremely rare. The main time that excessive bleeding can be a risk is when large-breed, obese, in-heat or pregnant dogs are spayed. Large breed, in heat and pregnant dogs have much larger uterine and ovarian blood vessels than normal sized, non-estrus, non-pregnant dogs do and the vet has to be more careful when tying them off. Additionally, the uterine body of in heat dogs can be very soft and fragile - it runs the risk of tearing apart and bleeding excessively whilst the vet is in the process of tying it off. It is because of these increased risks that veterinary clinics warn against getting in-heat or pregnant dogs spayed and charge clients more to do so.

Look at the image opposite: this is the uterus of a pregnant cat being moved out through the abdominal incision line for desexing. See the massive blood vessels (red spidery structures) covering this organ? If the vet failed to tie off this cat's ovarian and uterine vessels properly, massive bleeding would occur!


6h. Septic peritonitis (very rare).
Peritonitis occurs when bacterial organisms gain access to the inside of the animal's abdominal cavity and replicate there, producing an excessive build up of infection, inflammation and pus in the space around the animal's abdominal organs. Essentially, it is as though the animal has a large abscess present within the inside of its belly!

In the case of dog spaying procedure, there are three main ways in which bacterial organisms can gain access to the animal's abdominal cavity and set up a septic peritonitis condition: via the incision line, via the uterus itself and via the blood stream.

The spay incision itself. Once you open up an animal's abdomen surgically, you expose it to bacteria, which are lurking in the surrounding environment and the animal's own skin. If the vet uses poor aseptic surgical technique during dog spaying surgery (e.g. the vet fails to wear gloves during the surgery) or poor skin preparation technique before the surgery (i.e. doesn't shave and scrub the skin properly) or performs the surgery on infected, diseased skin (bacterial numbers are very high in diseased skin and will easily enter the wound site during surgery), it is possible for bacteria to enter the dog's abdominal cavity during surgery and infect the abdomen, resulting in peritonitis. After the surgery, should the dog develop a suture-site infection or a wound-site abscess (already discussed in this section), it is theoretically possible for the bacteria in these wounds to track through the muscle-wall linea alba incision and invade the dog's abdominal cavity, setting up a peritonitis. If the animal were to eviscerate (herniate its intestines completely outside of its abdomen and skin - image opposite) then the risks of peritonitis would be very high because environmental bacteria would have a direct path into the dog's abdominal cavity!

The uterus. The most common reason why a dog would develop peritonitis after a dog spaying procedure is if the uterus being removed was diseased in some way or already highly-infected. The main times that this will occur is if the uterus is infected inside (e.g. pyometra or metritis - a uterus full of bugs and pus - see image below); rotten in some way (e.g. a uterine torsion/twist causing rotting of a section of uterus or a uterine intussusception causing death and rotting of the telescoped section of uterus - see the image of the rabbit uterus with the green, rotten intussusception: below) or if the animal is undergoing a caesarean section because of dystocia or trouble birthing (when an animal starts to give birth, it opens its cervix, which allows bacteria into the uterus - bacteria that can subsequently contaminate the animal's abdominal cavity when the uterus is opened to perform a caesarean section).

Uterine-origin peritonitis risk does not include animals that are desexed whilst merely in-heat or pregnant. In these situations, the vet does not usually have to open up the dog's uterus during surgery and, even if he did, the uterus of these animals is normally fairly sterile inside (i.e. a pregnant dog would not allow bacteria into the uterus to infect her developing puppies).


Image 1: This is a photograph picture of an infected dog uterus (pyometron) that has been removed during dog spaying surgery. The uterus has been cut open to reveal the infected contents of the uterine horn. The insides of the uterus are full of chunky yellow pus and bacteria. Had these bacteria entered the animal's abdominal cavity during dog spaying surgery, then a peritonitis might have resulted.

Image 2: This is a rabbit uterus with a rotten, green, bacteria-filled uterine intussusception.

The animal's blood stream. Bacteria floating through the blood stream will tend to lodge in surgical sites where tied-off blood vessels form a dead-end passage. If this occurs (thankfully, it is very rare), these animals may develop a peritonitis after surgery, even when the surgery itself and the after-care of the patient was perfect and not contaminated at all! It is to prevent this kind of bacterial translocation to the internal surgical sites via the blood that vets will not perform a dirty surgery (e.g. a dental) at the same time as performing a dog spay surgery. Dentistry seeds lots of nasty mouth bacteria through the blood stream, which could end up infecting an internal dog spay site.

Additional note 1: Very occasionally, peritonitis may result from a freak bug entering the surgical site (sometimes nasty bacteria like Golden Staph and flesh-eating Streptococcus and Mycobacteria species will find their way into a vet clinic and cause havoc). In such a situation, the animal may not require many bugs at all to enter the abdomen cavity in order to set up a life-threatening infection. This is not so much a problem of poor technique and inadvertent contamination, this is a problem of bacterial resistance (Super Bugs).

Additional note 2: Sometimes post-operative peritonitis may be the result of an animal having a poor or compromised immune system. It is not possible for even the best surgeon to perform internal surgery with zero bacterial contamination: there will always be a few bacteria that enter the abdomen from the skin or air. The best a surgeon can do is keep bacterial contamination as low as possible and hope that the animal's immune system can mop up any invaders that do get in. If an animal has an immune-suppressive disease (e.g. Cushing's disease, Diabetes Mellitus and animals on immune-suppressive drugs and chemotherapy), its body may not be able to mop up the invading bacterial pathogens enough to prevent peritonitis from setting in.

Dogs with full-blown, septic peritonitis are usually extremely sick. They will often present to the vet with severe abdominal pain, restlessness, abdominal distension (swelling and bloating of the belly), inappetence (not-eating), lethargy, high fever and even vomiting. Severe cases may even present to the vet in severe septic shock, as a result of bacteria and bacterial toxins flowing through the bloodstream (blood poisoning or septicemia). These shock-affected animals may have cold, pale gums and extremities or, conversely, hot, brick-red coloured gums and they may be so listless that they give their owner almost no response (some can be almost comatose). By the time some of these animals get to the vet, they could well be suffering from the secondary life-threatening complications of shock and multiple-organ-failure, including: renal failure, liver failure and pulmonary edema (fluid in the lungs).

Diagnosis of the condition is usually made by inserting a needle into the animal's abdomen and sampling the fluid there. If that belly fluid contains high numbers of degenerate neutrophils (a type of white blood cell that responds aggressively towards bacterial infections) and bacterial organisms, then the diagnosis is septic peritonitis.

Animals that develop septic peritonitis (bacterial infection of the abdominal cavity) require a lot of intensive and expensive in-hospital care to save their lives. Some animals will even need to be surgically opened up again so that the vet can physically wash the pus and infection from their belly. Because these animals are often so very sick, animals with septic peritonitis must be given a guarded prognosis for recovery. Many peritonitis patients that do recover will go on to develop adhesions (scar bands between organs), which can pose later problems for the animal's organ function and health.


6i. Ureter laceration (extremely rare).
In the diagram image below, you can see that the ovaries and uterine horns (pink) are located very close to the animal's kidneys (maroon) and ureters (the yellow tubes sticking out of the kidneys, which lead to the animal's bladder). Because the ureters run so close to the uterus, it is theoretically possible (very rare) for a careless or inexperienced surgeon to slice into or through the dog's ureter/s when performing a dog spaying operation.



If this occurred, a very severe, costly and potentially life-threatening situation would result.

Rupture of the ureter would result in urine leaking from the torn ureter into the fat around the kidneys and, from there, into the abdominal cavity itself. Dog urine is very acidic and irritant and leakage of urine into the animal's abdominal cavity would result in severe urine peritonitis (also termed uroperitoneum): severe urine-induced tissue swelling, pain and inflammation of the abdominal cavity. Additionally, because the excretion of urine from the animal's body is responsible for removing many toxins and nasty metabolic products (e.g. urea, creatinine, excess potassium) from the animal's bloodstream, the animal with ureteral rupture will also start to retain these toxins within itself, resulting in it becoming very unwell over a matter of days.

Animals with uroperitoneum from a ruptured ureter are often extremely sick. They will often present to the vet with severe abdominal pain, restlessness, abdominal distension (swelling of the belly), inappetence (not-eating), lethargy and even vomiting. If both ureters have been cut, the animal will often not have passed any urine in some days (the urine is pooling inside the abdomen, not leaving the body via urination). Severe cases allowed to progress will present to the vet in extreme shock. These animals will have cold, pale gums and extremities and they may be so listless that they give their owner almost no response (some can be almost comatose). Some of these animals will even be vomiting blood, passing black, tarry stools and some will have developed mouth ulcers and halitosis (bad breath), as a direct result of the ulcerative effect of the accumulated toxins on the animal's intestinal tract. Some patients will have life-threateningly low heart rates: the effect of extremely high levels of blood potassium acting upon the heart. By the time some of these animals make it to the vet, many will be suffering from the secondary life-threatening complications of shock and multiple-organ-failure, including: renal failure, liver failure and pulmonary oedema (fluid in the lungs).

Diagnosis of the condition is usually made by putting a needle into the animal's abdomen and sampling the fluid there. If that fluid contains high levels of urea and creatinine (the toxins normally excreted by the kidneys), then the diagnosis is uroperitoneum. Further radiographic dye studies can then be used to determine where the ureteral rupture is located.

Important note: a major differential diagnosis for this condition would be outright renal failure (see next section).

Such an animal would be expected to be very unwell (would need 24 hour care) and very painful. A lot of intensive and expensive in-hospital care may be needed to save these animals' lives. Laceration of a ureter requires urgent surgical repair and there is a high risk that the animal might develop ureter strictures (scarring and narrowing of the ureter passage) and ureter blockage down the track. Because these animals are often so very sick and the costs of repair so high, animals with urine peritonitis and ureteral rupture must be given a very guarded prognosis for recovery.


6j. Post-operative renal failure (kidney failure).
Although anaesthetic drugs are much less cardiovascularly depressant (depressant on blood pressure) and rough on the kidneys and liver these days, there is still the possibility that an individual dog or puppy may develop acute renal failure immediately after or some days after any anaesthetic procedure, even such a quick, routine procedure as dog spaying.

Dogs can develop renal failure if their blood pressure drops below certain critical levels during anaesthesia (e.g. if the animal receives a drug that suppresses its cardiac contractility and/or heart-rate, resulting in reduced blood pressures). Kidneys require that a certain pressure of blood goes through them in order for them to receive enough nutrients and oxygen to stay alive and functional (they are sensitive to low blood pressures and become damaged easily). Dogs can also go on to develop acute renal failure if they experience a severe surgical complication that causes their blood pressures to fall critically during anaesthesia (e.g the animal experiences severe bleeding and blood loss during the anaesthetic - see 6f-6g).

Kidneys require a minimum systolic blood pressure of 90mmHg and a mean arterial blood pressure over 60mmHg to survive. Blood pressures below these levels are very dangerous.

Animals may also develop renal failure because they received an anaesthetic or pain-killer drug (or both) during the surgical procedure that had toxic side effects on the kidneys. For example, certain NSAIDs (non-steroidal anti-inflammatory drugs) used for pain relief act by inhibiting the formation of prostaglandins: common body-chemical initiators of pain and inflammation (inhibiting prostaglandin production is how these drugs work to reduce pain). Body prostaglandins, however, also have an additional role in protecting the kidneys from the damaging effects of low blood pressure. In times of low blood pressure, the blood vessels leading into the kidneys release prostaglandins, which causes these vessels to dilate and the kidneys to, therefore, receive more blood and oxygen. Certain NSAIDs inhibit the protective action of prostaglandins in the kidneys, resulting in a kidney that is more prone to becoming damaged if blood pressures fall (as they often do during surgery).

Additionally, because the kidneys are designed to filter waste and toxins from the body, a lot of commonly-used anaesthetic and pain relief drugs require these organs in order to be cleared from the body. Kidneys, particularly kidneys already compromised by age, low surgical blood pressures or pre-existing disease, may not be able to tolerate these drugs moving through them and may, as a result, become injured and fail to function.

Renal failure after dog spaying surgery is more common when aged animals (>8 years) are operated on. These older animals are more likely to already have some degree of renal compromise and the compounding effects of low blood pressures during anaesthesia as well as the effect of renal-toxic drugs (esp. non-steroidals), can be enough to push their kidneys over the edge. It is for this reason: to detect mild, sub-clinical renal disease that might be exacerbated by surgery, that most vets insist on pre-anaesthetic blood panels being performed prior to performing surgery on older dogs.

Young dogs, however, are not totally immune from suffering the effects of acute renal failure after surgery. Certain breeds of dog: e.g. Bull Terriers, Shar Peis and a number of others; are prone to a range of congenital renal defects and diseases. Animals affected with such conditions are more likely to already have some degree of renal compromise by the time of spaying and the compounding effects of low blood pressures during anaesthesia as well as the action of renal toxic drugs (esp. non-steroidals), can be enough to push their kidneys over the edge, even though they are only young animals (and thus, presumably healthy). It is for this reason: to detect mild, sub-clinical, congenital renal disease that might be exacerbated by surgery, that many vets offer pre-anaesthetic blood panels prior to performing dog spaying surgery on young dogs. It is often a box that can be ticked on the anaesthetic permission form.

Animals that do develop acute renal failure after dog spaying surgery will often become very sick within about 24-72 hours after surgery. These dogs will drink excessively or not at all, they will go off their food, they will often vomit (the vomit may contain blood), they will become very depressed and listless to the point of being non-responsive, they will become dehydrated, they will stop urinating (or only urinate rarely) and they may start to pass black, tar-colored faeces or diarrhea.

Animals presenting with these signs after any surgery must see a vet. Animals with acute renal failure will require aggressive and intensive (and expensive) therapies to save their lives. Many animals with severe, acute renal failure will not recover.

The risk of post-operative renal failure can be reduced by letting the vet perform a pre-anaesthetic blood profile on the dog, young or old, prior to dog spaying surgery. In this way, early renal disease may be picked up. Vets can also reduce the risk of dogs developing renal failure by performing swift surgeries; monitoring blood pressures during surgery and by not giving the animal non-steroidal drugs prior to surgery, only afterwards, as the pet is recovering.


6k. Anaesthetic death (rare but does occur).
Very rarely, but often enough that most vets will have encountered a few during their careers, a young "healthy" dog booked in for a routine desexing procedure will inexplicably die. This is, needless to say, very distressing for the owner and for the veterinarian alike (having had one inexplicable death myself, I do vouch for this) and people will demand answers. The fact of the matter is that, while in some cases we vets can determine the cause of an anaesthetic death (e.g. the dog bled to death because it had eaten rat poison prior to surgery and no-one knew about it; the dog developed an acute, fatal anaphylactic reaction to an anaesthetic drug; the dog was not monitored properly during or after anaesthesia and died; the dog vomited on recovery, inhaled its vomit and died and so on), in a good many more cases the exact reason for death can not be determined. The animal simply died and we have no idea why. We presume that these animals may have had a pre-existing disease; suffered a sudden, fatal heart arrhythmia (a heart problem never picked up before); suffered a drug reaction; suffered a "stroke" (blood clot entering the brain) or thrown a blood clot into the lungs or heart, but we never actually find the cause of death.

7. Late complications, side effects or problems associated with female dog spaying.

7a. Weight gain.
Not really a complication per se, but an often complained about sequelae of dog spaying surgery.

Studies have shown that spayed animals probably require around 25% fewer calories to maintain a healthy bodyweight than entire female animals of the same weight do. This is because a spayed dog has a lower metabolic rate than an entire dog. Because of this, what tends to happen is that most owners, unaware of this fact, continue to feed their spayed female dogs the same amount of food calories after the dog spaying surgery that they did prior to the surgery, with the result that their dogs become fat. Consequently, the myth of automatic obesity has become perpetuated through dog-owning circles and, as a result, many owners simply will not consider desexing their dogs because of the fear of them gaining weight.

Author's note: The fact of the matter is that most dogs will not become obese simply because they have been desexed. They will only become obese if the post-spaying drop in their metabolic rate is not taken into account and they are fed the same amount of food calories as an entire animal. Any weight gain that is experienced can be reversed through not feeding the dog as many calories and treats.


7b. Ovarian remnants (incomplete dog spaying) - spayed dogs coming into heat after spaying surgery.
Occasionally, a dog who has been spayed will come back into season (heat) weeks to months (even up to 5 years later) after it has been desexed. This is, naturally, very perplexing and annoying for the owner (part of the reason why people get female dogs desexed is to prevent them from displaying the more annoying signs of dog heat like swelling of the vulva, attraction of males and roaming) and often owners will question whether or not the surgery has been performed at all.

Well, the good news is that, despite the in heat symptoms, the dog probably has been desexed successfully and so can not fall pregnant (unless some major record-keeping mistake has been made and the dog is thought to have been spayed when it wasn't ...). The bad news is that the dog has probably had some of its ovarian tissue (a portion of ovary or ovarian-type tissue) left behind and the remaining ovarian follicles (called ovarian remnants) are now cycling and producing estrogen, which accounts for the dog showing signs of being in heat after spaying. This is not a huge problem for the dog (it won't get pregnant), however, the signs of heat and the attraction of male dogs into the yard will continue as long as the ovarian remnants remain and this can be tiresome for the dog-owner.

Dog with ovarian remnants should not be able to get pregnant because the ovarian tissue left behind is not in communication with a uterus. What the ovarian remnant dog can occasionally develop, however, is a condition called a stump pyometron: a bacterial infection of the small section of uterine body (uterine stump) that has been left behind after dog spaying surgery. Pyometron is an infection of the uterus or uterine stump that most commonly develops under the hormonal influence of a cycling ovary or ovarian remnant (i.e. it results from the cycle of estrogen and progesterone release by the ovary). The infection that occurs can be life threatening. Animals without cycling ovarian tissue at all are very unlikely to suffer from the pyometra condition and so, for this reason, it is advisable that dogs with symptoms suggestive of ovarian remnants (return to heat, roaming, male dog attraction etc) undergo work-up and surgery to remove the section/s of ovary left behind. This should prevent a 'stump pyo' from occurring.

Author's note: The presence of ovarian remnant syndrome does not always mean that the vet has performed the surgery incorrectly. Some dogs are actually born with pockets of ovarian tissue that are located outside of the ovary body - typically further down the ovarian pedicle, but occasionally (very rarely) even elsewhere in the body (these are termed ectopic ovaries)! What happens in these cases is that the precursor stem cells that create the ovarian follicles in the canine embryo sometimes get lost during their migration to the ovary site and set up shop elsewhere in the body. In these cases, there is no way that the vet can know that a portion of ovarian tissue has been left behind, until the dog returns to heat after spaying surgery.

Differential (alternative) diagnosis of ovarian remnant syndrome:
Occasionally estrogen-secreting tumors of ovarian or non-ovarian cellular origin can develop, which secrete enough estrogen to produce signs of heat in entire or desexed female dogs. This is not ovarian remnant syndrome or a consequence of poor desexing technique, but it can look very similar. These secretory tumours can arise in an ovarian remnant that has been left behind by spaying or they can occur in other non-ovarian tissues anywhere in the body. Alternatively, if a dog already has an estrogen-secreting ovarian cancer and it is spayed to remove it, the dog may continue to shows signs of heat after surgery if that secretory tumour has managed to spread seeds (metastasize) into other organs prior to desexing surgery. The tumour 'seeds' can be equally secretory, producing signs in the dog similar to ovarian remnant syndrome.

Diagnosis of ovarian remnant syndrome:
There are several ways of diagnosing this condition and ruling out the differential diagnosis of estrogen-secreting neoplasia (cancer).

1) Vaginal cytology: The presence of large quantities of estrogen in the blood can be confirmed through vaginal cytology (swabbing and microscopically examining the cells of the dog's vagina whilst it is showing heat signs). In the presence of estrogen, these cell populations are very distinctive. Note, however, that both of the conditions mentioned above should show vaginal cytology changes supportive of high estrogen levels, not just ovarian remnant syndrome, so cytology is not a useful differentiating test in this regard.

2) The heat symptoms: In both of these conditions, the dog in question should show signs of coming into heat sometime after spaying. In the case of ovarian remnant syndrome, however, this heat activity should be observed to 'come and go' as the remnant ovarian follicles cycle through repeated stages of growth (the follicle grows - producing estrogen and signs of heat) and disintegration (the follicle ovulates, turns into a corpus luteum and makes progesterone instead without signs of heat): a cycle typical of the reproductive cycle of a normal entire female dog. In the case of estrogen-secreting tumours, however, the symptoms of heat are generally more persistent and non-waning because the production of estrogen by these diseases is persistent.

Author's note: Very occasionally, a dog with ovarian remnant syndrome will show persistent estrus signs, not just the "coming and going" signs typically seen in this condition.

3) Detection of ovulation and response to certain pituitary hormones: Because ovarian remnants are essentially normal ovarian tissue (just tissue that has been left behind), they should produce ovarian follicles that grow and ovulate normally (as described in point 2, above) and that respond to certain regulatory pituitary-derived hormones (e.g. GnRH, hCG, LH) in the normal way. Estrogen-secreting tumours, on the other hand, do not produce normal follicles that ovulate and nor do they respond to pituitary-derived hormones in the normal way. Consequently, proving that a dog's estrogen-secreting tissue is capable of ovulation and that it responds to pituitary hormones is another very good way of confirming the presence of ovarian remnants (as opposed to estrogen-secreting tumours). This can be done in two ways:

3a. Measure the dog's progesterone levels one week after the signs of estrus (heat) have resolved. In a dog with ovarian remnant syndrome, the cessation of estrus signs should be the result of ovulation of the estrogen-secreting follicles and their replacement with progesterone-secreting corpus lutea. A progesterone level of >2ng/ml is suggestive of ovulation having occurred (i.e. a diagnosis of ovarian remnant syndrome).

3b. Induce the dog to ovulate using hCG (human chorionic gonadotropin) or GnRH (gonadotrophin releasing hormone). If a dog with ovarian remnant syndrome is given either 10IU/kg of hCG or 0.5ug/kg of GnRH whilst she is in heat (showing signs of heat), she should ovulate. A week later, her serum progesterone levels should be >2ng/ml, which is supportive of ovulation having occurred. A spayed dog with an estrogen secreting tumour should not ovulate in response to hCG or GnRH and, consequently, no rise in progesterone levels one week after administration of these hormones should be found.

4) Surgical exploration: The definitive way to find an ovarian remnant is to take the dog back to surgery and have a look inside the dog's abdomen for the remnant. Not that they are always that simple to find: ovarian remnants can be very small and hard to find (they are just a small cluster of cells after all). The BEST time to perform exploratory surgery on an ovarian remnant dog is when it is actively showing signs of being in-heat (attracting males, showing vulval swelling). At these times, the ovarian follicles should be large and easy for the vet to find.

Treatment of ovarian remnant syndrome:
The surgery to remove an ovarian remnant is almost identical to the surgery performed when a dog spaying procedure is done, except that, in this case, there is no uterus to remove. The surgeon enters the animal's abdomen and investigates the regions just behind each of the dog's kidneys until the ovarian follicles are found and removed. Both sides should be examined, because remnants can be bilateral (both sides). If they can be found and removed, then all of the symptoms of heat and cycling should resolve for that dog.

The BEST time to perform corrective surgery on an ovarian remnant dog is when it is actively showing signs of being in-heat. At these times, the ovarian follicles should be large and easy for the vet to find.


7c. Incontinence after dog spaying surgery.
There is a concern that female dog spaying, particularly early age dog spaying prior to the animal having its first season, may cause the female animal to develop urinary incontinence problems later on.

The reason for these incontinence problems seems to be the post-spaying drop in body estrogen levels. Estrogen has an important effect on canine bladder sphincter tone - it helps the bladder neck to remain tightly sealed when the animal is not intentionally micturating (urinating), thereby preventing urine from leaking out of the bladder involuntarily. In other words, estrogen helps to maintain urinary continence. When the dog is desexed, this estrogen effect is lost along with the animal's ovaries and, as a result, the animal's bladder neck (bladder sphincter) may become less 'tight' resulting in episodes of uncontrolled urine dribbling (termed urinary incontinence), especially when the pet is asleep. We do know that estrogen has an important effect on bladder sphincter tone and urinary continence because this hormone used to be used widely in the management of female canine incontinence prior to the introduction of safer incontinence-treating drugs (e.g. phenylpropanolamine).

Certainly this issue of post-spaying incontinence does seem to be a well-known problem in dogs. It is far more common for incontinence problems to develop in desexed bitches as they get older, than it is for the problems to develop in older, entire bitches. Anywhere from 2-20% of spayed bitches, regardless of spaying age, will develop incontinence issues some time after desexing. Although early age desexing is commonly blamed for the problem (i.e. many people think that the problem only occurs if the bitch is spayed prior to having its first season), the reality is that urine incontinence problems can also occur in bitches that are spayed at older ages and after several seasons. (Author's note: urinary incontinence may, however, be 'more common' in early age desexings - it just might be that estrogen surges in the young bitch's first few seasons is necessary to maintaining normal bladder neck tone and continence in later life.)

But is it only a problem of oestrogen loss?
To throw an additional spanner in the works, some veterinary texts suggest that it is not just the timing of the spaying procedure with regard to the first season that is at fault, nor is it solely the absence of estrogen that results in the post-spaying incontinence problem, but that it could be the surgical dog spaying techniques being used. Historically and now, veterinarians have always desexed dogs by taking out as much of the uterine body as they can; as close to the animal's cervix as physically possible. They did this in order to prevent a condition called a stump pyometron (a nasty abscessation of the residual uterine body or "stump" left behind at surgery). It is possible, however, that such a radical uterine body resection, resulting in sutures being placed just above the cervix (which lies between the animal's colon and bladder neck), may be causing granulomas and adhesions to form between the uterine stump and the bladder neck. These adhesions could potentially result in warping and displacement of the bladder neck, which could compromise the bladder's sphincter function leading to incontinence. It has been proposed that only removing the upper uterine horns and ovaries (not the uterine body) may be preferable, thereby avoiding interference with the bladder neck region altogether. Food for thought.

Note that stump pyometron could become an issue if this technique (called a partial ovariohysterectomy or an ovariectomy) was used, necessitating that extra care be taken in surgery not to leave any ovarian remnants behind. Additionally, ovariectomy is only ever recommended in non-pregnant young animals with normal uteruses. It should never be used as a technique to desex dogs with significant uterine disease. In such cases full ovariohysterectomy is recommended as it is important to remove as much of the diseased uterus as possible.

Recommendations?
As of this writing, I would not recommend holding off on desexing a female dog before its first season or otherwise simply out of the fear of older-age incontinence. The incontinence condition is not all that common and, if it should occur, it is generally easily managed with medication. Additionally, it should not be overlooked that there is a greater incidence of mammary cancer in dogs that are desexed after their first season (early spaying is protective). If, however, your dog is young (before the age of its first season) and it is already showing some signs of poor bladder control (e.g. leaking urine when sleeping, involuntarily losing bladder control in the house ...), it might be better to let the animal have one season before desexing it so that if the initial surge in estrogen (puberty) does have a beneficial effect on future bladder tone, it can be taken advantage of.

As the issues of 1) post-spaying incontinence; 2) partial ovariohysterectomy/ovariectomy and 3) allowing or not-allowing the animal to have a first season in the interests of avoiding incontinence problems are all contentious issues, I would recommend that concerned pet owners talk any issues over with their own vet before making any crucial dog spaying (or non-spaying) decisions on this matter.







8. Frequently asked questions (FAQs) and myths about spaying dogs:

This section outlines some of the commonly held myths and misconceptions about female dog spaying surgery and answers some of your commonly asked questions.

8a. Myth 1 - All spayed dogs gain weight (get fat).
I have previously discussed this topic in other sections of this webpage: it is a commonly held belief that is, quite simply, not true.

Studies have shown that spayed canines probably require around 25% less calories to maintain a healthy bodyweight than entire female dogs of the same bodyweight do. This is because a spayed animal has a lower metabolic rate than an entire animal does. Because of this, what tends to happen is that most owners, unaware of this fact, continue to feed their spayed female dogs the same amount of food calories after the surgery that they did prior to the surgery, with the result that their pets become fat. Consequently, the myth of automatic obesity has become perpetuated throughout the dog-owning circles and, as a result, many owners simply will not consider desexing their female dogs because of the fear of them gaining weight.

Author's note: The fact of the matter is that dogs will not become obese simply because they have been desexed. They will only become obese if the post-spay drop in their metabolic rate is not taken into account and they are fed the same amount of food calories as an entire animal. Any weight gain that is experienced can be reversed through not feeding the pet as many calories and treats.


8b. Myth 2 - Without her reproductive organs, a female dog won't feel like herself (i.e. she "won't be a woman").
It is common these days for humans to attribute human feelings and emotions (e.g. love, sadness, grief and so on) onto their animals and, in doing so, make them out to be more human than they actually are. Whilst dogs almost certainly do have some understanding of concepts like affection and companionship and loss and needing to behave in a certain way to fit in with the family and receive food and so on, to then extrapolate their needy, cuddly behaviour further, as many pet owners do, and claim that these animals act well-behaved and cuddle up to us as a sign of their "love" for us is probably a little far-fetched. They cuddle up, they get food and affection: simple as that. Action, reward.

In a similar fashion, this dog spaying myth is probably just another common example of human emotions being incorrectly attributed onto our pets. What often happens is that, because the owner believes that she herself would feel incomplete and therefore "not a woman" without her own ovaries and uterus, then so will her dog feel the same way if her reproductive organs are taken away.

The fact of the matter is that dogs probably barely even notice that their reproductive organs are missing. They certainly don't seem to be in any way depressed about it (as a human in the same situation would be) and they tend to go about their doggy business just the same as always once the procedure is performed. If dogs were truly depressed or worried about being spayed, then there would probably be some sort of long term depression, shyness or behavioural change seen in them and this just does not seem to occur.


8c. Myth 3 - Female dogs need to have sex before being desexed.
No, no and no! Female dogs do not need a sexual experience to be in any way complete either emotionally or behaviorally. Similar to the myth above (myth 2), this is a situation where human emotions and desires have been superimposed on top of what is best for the animal. Allowing the pet to have a sexual experience prior to desexing may well lead to some established behavioural problems developing that persist even after spaying has occurred (e.g. roaming, aggression towards other dogs, urine marking). The "experience" could also result in an unwanted litter of puppies being born.

You could argue that, from a human emotional viewpoint, it is cruel to let the dog experience the "pleasures of sex" only to then take it all away from her by desexing. Better for her to never know what it feels like because then she won't know what she's missing.


8d. Myth 4 - Female dogs should be allowed to give birth to a litter before being spayed.
It is a common misconception that a female dog will only 'feel complete' and mature emotionally into an adult dog if she is allowed to have a litter of puppies. Absolutely not! Allowing a litter to be born simply because you feel that the 'dog should be allowed to be a mother' is very irresponsible and just results in more and more unwanted, dumped pups finding their way into pounds and shelters and waste-disposal units. Likewise, letting a dog have a litter so that you can demonstrate to your children 'the joys of birth' is also irresponsible and wrong. The animal is a family member, not an educational tool for your private use.


8e. Myth 5 - Vets just advise neutering for the money and not for my dog's health.
Whilst it is true that desexing, along with vaccination, worming and flea prevention, is one of the main bread-and-butter activities of the veterinary profession, we do not advocate the procedure just for the money. Face it, if money and not the animal was all that we considered when making these decisions whether to operate or not, then vets in Australia (can't vouch for the rest of the world) would still be tail-docking and ear-docking pets and we would now be starting to see many veterinary surgeons dabbling in pointless cosmetic surgery to suit an owner's particular aesthetic tastes (as does occur overseas). If money was our only concern, veterinarians would not now be promoting 3-yearly vaccine regimens for dogs instead of the previously popular and highly lucrative yearly vaccinations.

Surgical procedures are not without risk to the animal (see sections 6 and 7 on surgical complications) and, therefore, vets do not advocate surgical procedures, including desexing, if there is no benefit for that animal or society as a whole. The benefits of surgery must outweigh the risks. Vets advocate the desexing of male and female dogs for all of the population control, genetic disease control and medical and behavioural benefits previously discussed (section 2).

Another thing to consider is that, by advocating the mass desexing of animals, we veterinarians are essentially desexing ourselves out of business. Fewer puppies around means fewer vaccinations and fewer clients. Veterinarians could be making a lot more money out of all of the caesarean sections and dystocias (inability to give birth) and pyometrons and mammary cancers and testicular cancers that would be the result if we weren't pushing desexing so aggressively.


8f. FAQ 1 - Why won't my veterinarian clean my dog's teeth at the same time as spaying her?
Veterinarians the world over have a policy of not performing a "dirty" surgery at the same time as a "clean" surgery.

A dirty surgery is a surgery or procedure whereby the tissues involved already have a high level of bacterial contamination, such that many bacteria are likely to be released into the animal's bloodstream and surrounding tissues as a direct result of the surgical or medical procedure. Dentistry is a good example of this - when an animal gets its teeth cleaned, millions of bacteria from the teeth and gums are released into the animal's blood stream.

A clean surgery is a surgery or procedure with minimal bacterial contamination risk. Desexing and orthopedic surgeries are common examples of clean surgeries.

The reason why most veterinarians will not perform a dirty surgery (such as a dental scale and polish) at the same time as they will a clean surgery (e.g. dog spaying) is because of the risk that bacteria from the dirty surgery will travel throughout the animal's bloodstream and lodge in the site of the clean surgery. This could result in infection setting up in the site of the clean surgery (i.e. peritonitis - see section 6h), which could be disastrous in situations like orthopedic operations and dog spaying surgeries, which are supposed to remain as sterile and bacteria-free as possible.


8g. FAQ 2 - Why shouldn't my vet vaccinate my dog whilst she is under anaesthetic?
In order for vaccines to work effectively, the animal needs to have a fully functional immune system that is capable of responding to the vaccination contents. See our great "How vaccines work" page for more details on the immune response to vaccination.

The reason why most vets will not vaccinate a dog that is undergoing an anaesthetic procedure is because the animal's temperature will often fall to below normal levels when it is under an anesthetic. Since many of the body's immune cells do not work as well when body temperatures are very low, there is the risk that the vaccination might fail to induce the full immunological protective response if it is given to a cold animal. Hence the reason why vets don't vaccinate anesthetized dogs.


8h. FAQ 3 - Can my dog be spayed whilst she is in heat?
It is possible for dogs to be spayed whilst they are in heat (at the shelter we do it all the time), it is just not as ideal or as safe as performing the procedure on a non-cycling animal. The uterus of an in heat dog is very thickened and non-stretchy and friable (it falls apart easily), with very large ovarian and uterine blood vessels leading into it. A much longer incision needs to be made into the dog's abdomen to remove it safely (trying to pull it out through a small abdominal incision can result in the uterus tearing and falling apart) and there is a much greater chance of the uterus tearing apart and bleeding as it is being removed. In addition to this, the in heat surgery takes longer to perform (longer anaesthetic time) and costs more to the client.

Note: If you do decide to wait until the dog has finished her heat before desexing her, you should hold off on surgery for at least 2 weeks past the signs of heat subsiding (i.e. two weeks after the season has ended). Obviously, if there is a chance that the dog has been mated during that heat, then you should elect to get her desexed as soon as possible (see next section on pregnant dog spaying).


Image 1: This picture shows two uteruses that have been removed from similarly-sized cats during cat spaying surgeries. The image clearly shows the difference in uterine horn size (and thus surgical risk) between the two spays. The uterus on the left is an early-age, non-cycling uterus: the uterine horns are thinner and stretchier (they don't break easily) to handle and they do not have as much blood supply, making them appear paler pink in colour (they don't bleed much if they are accidentally torn). The uterus on the right is a cycling, immediately-post-estrus uterus: the uterine horns are thicker and more friable (they tear easily) to handle and they have a large blood supply, making them appear darker pink in colour (they bleed a lot if they are accidentally torn).

Pic 2: This is a close-up image of the uterus on the right. The uterine horn has been cut open to show the extreme thickness of the uterine wall. This would bleed a lot, were it to be torn during spaying surgery.


8i. FAQ 4 - Spaying a pregnant dog - can my pregnant dog be spayed?
It is possible for dogs to be spayed whilst they are pregnant (this is commonly done in many shelters in order to prevent puppies from being born into a crowded, infectious-disease-abundant environment), however, it is not as safe nor as ethical as performing the procedure on a non-pregnant animal. The procedure is, after all, performing an abortion on a creature that can not choose for itself and many veterinary staff and clients do have concerns about the ethics of this.

From a procedural and safety viewpoint, the uterus of a pregnant dog is very large and thickened compared to a non-pregnant uterus, with extremely large ovarian and uterine blood vessels supplying it. A much longer incision needs to be made into the dog's abdomen in order to remove a pregnant uterus safely (trying to pull a large, pregnant uterus out through an undersized abdominal incision can result in the uterus tearing and falling apart and contaminating the abdominal cavity with fetal and placental fluids) and, because there is a much greater chance of a pregnant uterus haemorrhaging as it is being removed, extra care has to be taken in ligating the ovarian and uterine blood vessels. In addition to this, the surgery takes longer to perform (longer anaesthetic time) and it costs more to the client.

Important note: If you are going to get a pregnant dog spayed, get the surgery done as soon as possible (i.e. when the very first signs of pregnancy appear or when you notice the dog being mated). Many vets will not perform a dog spaying surgery on a late pregnant dog (e.g a dog within 2-3 weeks of birthing) and you could well be left with a litter of pups to rear.

Note: If you do decide to wait until the dog has had its puppies before spaying her, then you should wait until the puppies are weaned (at 5-6 weeks).


8j. FAQ 5 - My pregnant dog needs a caesarean (C-section) - can she be spayed at the same time?
It is possible to desex a female dog after the puppies have been removed by caesarean section, however, a lot of veterinarians don't like to do this if it can be avoided. Most vets prefer to close the uterine incisions and close the dog's abdomen as soon as possible and have the female dog return to the vet clinic in a month or two for dog spaying surgery. The reason for this is that the extra dog spaying surgery does add greatly to the caesarean section anaesthetic time, which might be risky in an animal whose health has already been somewhat compromised by placental blood loss and by a period spent trying to give birth prior to the C-section being started. The longer surgery will also increase the dog's post-operative recovery time and may potentially affect her ability to mother her puppies. Additionally, performing a dog spaying procedure on an opened uterus does increase the risk of fetal fluids and uterine contents entering the animal's abdominal cavity, which could increase the risk of the animal developing peritonitis.


8k. FAQ 6 - Will dog spaying make my dog incontinent?
There is a concern that female dog spaying, particularly early age dog spaying prior to the animal having its first season, may cause the female animal to develop urinary incontinence problems later on.

The reason for these incontinence problems seems to be the post-spaying drop in body estrogen levels. Estrogen has an important effect on canine bladder sphincter tone - it helps the bladder neck to remain tightly sealed when the animal is not intentionally micturating (urinating), thereby preventing urine from leaking out of the bladder involuntarily. In other words, estrogen helps to maintain urinary continence. When the dog is desexed, this estrogen effect is lost along with the animal's ovaries and, as a result, the animal's bladder neck (bladder sphincter) may become less 'tight' resulting in episodes of uncontrolled urine dribbling (termed urinary incontinence), especially when the pet is asleep. We do know that estrogen has an important effect on bladder sphincter tone and urinary continence because this hormone used to be used widely in the management of female canine incontinence prior to the introduction of safer incontinence-treating drugs (e.g. phenylpropanolamine).

Certainly this issue of post-spaying incontinence does seem to be a well-known problem in dogs. It is far more common for incontinence problems to develop in desexed bitches as they get older, than it is for the problems to develop in older, entire bitches. Anywhere from 2-20% of spayed bitches, regardless of spaying age, will develop incontinence issues some time after desexing. Although early age desexing is commonly blamed for the problem (i.e. many people think that the problem only occurs if the bitch is spayed prior to having its first season), the reality is that urine incontinence problems can also occur in bitches that are spayed at older ages and after several seasons. (Author's note: urinary incontinence may, however, be 'more common' in early age desexings - it just might be that estrogen surges in the young bitch's first few seasons is necessary to maintaining normal bladder neck tone and continence in later life.)

But is it only a problem of oestrogen loss?
To throw an additional spanner in the works, some veterinary texts suggest that it is not just the timing of the spaying procedure with regard to the first season that is at fault, nor is it solely the absence of estrogen that results in the post-spaying incontinence problem, but that it could be the surgical dog spaying techniques being used. Historically and now, veterinarians have always desexed dogs by taking out as much of the uterine body as they can; as close to the animal's cervix as physically possible. They did this in order to prevent a condition called a stump pyometron (a nasty abscessation of the residual uterine body or "stump" left behind at surgery). It is possible, however, that such a radical uterine body resection, resulting in sutures being placed just above the cervix (which lies between the animal's colon and bladder neck), may be causing granulomas and adhesions to form between the uterine stump and the bladder neck. These adhesions could potentially result in warping and displacement of the bladder neck, which could compromise the bladder's sphincter function leading to incontinence. It has been proposed that only removing the upper uterine horns and ovaries (not the uterine body) may be preferable, thereby avoiding interference with the bladder neck region altogether. Food for thought.

Note that stump pyometron could become an issue if this technique (called a partial ovariohysterectomy or an ovariectomy) was used, necessitating that extra care be taken in surgery not to leave any ovarian remnants behind. Additionally, ovariectomy is only ever recommended in non-pregnant young animals with normal uteruses. It should never be used as a technique to desex dogs with significant uterine disease. In such cases full ovariohysterectomy is recommended as it is important to remove as much of the diseased uterus as possible.

Recommendations?
As of this writing, I would not recommend holding off on desexing a female dog before its first season or otherwise simply out of the fear of older-age incontinence. The incontinence condition is not all that common and, if it should occur, it is generally easily managed with medication. Additionally, it should not be overlooked that there is a greater incidence of mammary cancer in dogs that are desexed after their first season (early spaying is protective). If, however, your dog is young (before the age of its first season) and it is already showing some signs of poor bladder control (e.g. leaking urine when sleeping, involuntarily losing bladder control in the house ...), it might be better to let the animal have one season before desexing it so that if the initial surge in estrogen (puberty) does have a beneficial effect on future bladder tone, it can be taken advantage of.

As the issues of 1) post-spaying incontinence; 2) partial ovariohysterectomy/ovariectomy and 3) allowing or not-allowing the animal to have a first season in the interests of avoiding incontinence problems are all contentious issues, I would recommend that concerned pet owners talk any issues over with their own vet before making any crucial dog spaying (or non-spaying) decisions on this matter.


8l. FAQ 7 - Is dog spaying safe? It's just a routine procedure isn't it?
There is no such thing as a routine or "safe" anaesthetic procedure, regardless of whether the procedure is elective or not. There is always the risk, albeit small, that a normal, healthy individual animal or human may not wake up from an anaesthetic process or that it will develop a potentially fatal complication from having had surgery or anaesthesia performed (e.g. renal failure, sepsis).

In the case of dog spaying, yes it is a "routine" procedure insofar as we vets perform thousands of them every year. For the most part, the complications of the dog spaying procedure are exceptionally rare: very very few animals die or suffer severe, life-threatening complications as a result of dog spaying surgery. To say that the procedure is perfectly safe, however, would imply that nothing bad can ever happen and this is simply not true. Section 6 of this page lists a whole string of operative and post-operative complications that can occur, some of which can be fatal.


8m. FAQ 8 - My veterinarian offered to do a pre-anaesthetic blood screening test - is this necessary?
As mentioned in an earlier section, anaesthesia does drop the dog's blood pressure and place the animal's kidneys and liver under strain, both from the lower blood pressures and from the need to metabolize and excrete the anaesthetic drugs from the body. The pressure on and risk of damage to the kidneys and liver is much greater if those organs (liver and kidneys) are already compromised by disease or scarring (old-age changes).

The role of a pre-anaesthetic blood panel is to detect significant kidney and liver pathology before the dog has an anaesthetic procedure so that the vet can decide upon safer, alternative drugs or anaesthetic strategies to use or decide not to perform the procedure at all (e.g. if it elective - like dog spaying), thereby reducing the risks of a pet succumbing to post-operative renal or liver failure. The reason that a blood test is crucial in detecting if any pathology (disease) exists is because the veterinarian often can not tell what is going on in a dog's liver or kidneys from a clinical exam alone. The pet may look totally fine on the examination table and yet have only a small bit of renal function remaining. All the owner may notice at home is that the animal is drinking more water than normal and even this might not be all that obvious (especially if there is more than one dog in the household).

Most vets these days offer a pre-anaesthetic blood panel to all animals so that all owners have the option of checking their pet's kidneys and liver before an anaesthetic procedure is performed. Although this test is much more valuable in older animals (> 8 years old) because they are the age group most likely to have some degree of kidney or liver compromise, young animals may also benefit from pre-anaesthetic blood testing. Young animals are not immune from suffering the effects of acute renal or hepatic (liver) failure after surgery. Certain dog breeds (e.g. Bull Terriers, Shar Peis, Dobermanns and many others) are prone to various congenital renal and/or hepatic defects and affected animals are likely to have some degree of renal or liver compromise at a young age - this disease may first be picked up on a pre-anesthetic blood screen.

So, as to the question, "Is pre-anaesthetic blood screening necessary?" - I would say yes. In dogs over the age of 8 years, I would say that blood screening is very necessary because these older animals commonly develop organ dysfunction, which might only be detectable on a blood screening test. Diagnosing the problem before anaesthesia and taking it into account during anaesthesia may well prevent the animal from developing acute renal or liver failure after surgery. In animals under 8 years, I would say that blood screening is necessary, but more optional. Playing the odds, it is less common for an animal under 8 years of age to have severe liver or renal disease. However, if you are the kind of owner who wants to cover all of the safety bases for your canine friend, I would advise pre-anaesthetic blood screening in all animals that are to have an anaesthetic. This way, if your dog does happen to be one of the animals that has developed young-age kidney or liver issues, the problem will be detected prior to surgery commencing (it will also allow earlier diagnosis and treatment for the condition to start, which is beneficial for the prognosis).


8n. FAQ 9 - When is dog spaying high-risk or not safe to perform?
Dog spaying is not safe to perform on any dog which has a medical condition that precludes it from having a safe anaesthetic. Any disease or condition that results in compromise to the animal's heart rate, heart contractility, heart rhythm, respiratory function or ability to metabolize (break down) and excrete drugs may be exacerbated, perhaps terminally, by general anaesthesia. Examples of such diseases include: heart failure, cardiomyopathy, heart arrhythmias, pneumonia, shock, sepsis (systemic infection, causing shock), renal failure, liver failure and many more.

Any animal with a severe blood clotting disorder should not be operated on because it will not be able to clot its blood during the dog spaying surgery and could well hemorrhage to death. Examples include: platelet disorders, platelet deficiencies, hemophilias A, B and C, vwD, other congenital blood clotting disorders and rodenticide poisoning.

Any animal with severely infected or diseased skin in the region of the surgical site should not be operated on. These animals are likely to have a high level of superficial bacteria and this could well result in wound infection and wound break down.

9. The cost (price) of spaying a female dog:

Much as I would love to be able to do so, to attempt to place a flat $ figure on the costs of spaying a female dog would be grossly irresponsible of me and quite impossible to do. The cost of dog spaying is greatly variable and varies from place to place and region to region. It depends on many factors including: the size of the vet clinic, the competition the vet clinic has, the nature of the clinic (e.g. is it an animal shelter clinic or a commercial clinic?), the suburb the clinic is located in, whether the animal is in-heat or not, whether the animal is pregnant or not, the size and weight of the animal, the presence or absence of obesity, the occurrence of spay complications and so on.

In this section, I will attempt to give you an idea of the costs and the range of prices that may exist in one town/city when you are considering getting your dog spayed in Australia. (The principles discussed here will most likely apply to any city in the world). I will outline the ways that vets arrive at these prices and discuss ways that you can source lower cost and discount neutering.

9a. The typical cost of female dog spaying at a veterinary clinic.
For this section, I rang 9 of the veterinary practices in Canberra, Australia, asking about the costs of routine dog spaying, in-heat desexing and pregnant-dog-desexing. The clinics were chosen at random, aside from the fact that five of them were large, multiple-vet practices and the other four were small 1-2 vet practices. The prices (in Australian dollars) are listed below (for legal reasons, I can not identify the clinics I contacted).


Clinic 1:
Female dog spaying < 10kg - $310.
Female dog spaying 10-24kg - $365.
Female dog spaying 25-39kg - $420.
Female dog spaying > 39kg - $540.
Add $70 on if in heat or early-pregnant. Add $140 on if late pregnant.

Clinic 2:
Female dog spaying 1-15kg - $295.
Female dog spaying 15-30kg - $330.
Female dog spaying 30-45kg - $380.
Add $40-50 on if in heat. Add $50+ on if pregnant.

Clinic 3:
Female dog spaying < 10kg - $330.
Female dog spaying 10-25kg - $360.
Female dog spaying 25-40kg - $390.
Female dog spaying > 40kg - $440.
This clinic will not desex an in heat dog. Add at least $50 on if pregnant.

Clinic 4:
Female dog spaying < 10kg - $240.
Female dog spaying 10-25kg - $270.
Female dog spaying > 25kg - $320.
This clinic will not desex an in heat dog. Add at least $55 on if pregnant.

Clinic 5:
Female dog spaying < 10kg - $241.
Female dog spaying 11-22kg - $271.
Female dog spaying 23-45kg - $321.
Add at least $50 on if in heat or pregnant.

Clinic 6:
Female dog spaying < 15kg - $355.
Female dog spaying 15-30kg - $395.
Female dog spaying 30-45kg - $445.
Add at least $50 on if in heat or pregnant.

Clinic 7:
Female dog spaying < 15kg - $300.
Female dog spaying > 15kg - $330.
This clinic will not desex an in heat dog. Add at least $100 on if pregnant.

Clinic 8:
Female dog spaying < 12kg - $262-323.
Female dog spaying 12-30kg - $323-399.
Female dog spaying > 30kg - $399 and up (maximum would not be specified).
Add at least $50+ on if in heat or pregnant.

Clinic 9:
Female dog spay - $200 regardless of weight.
Add more on if in heat or pregnant (amount would not be specified).
This clinic also featured a 10% discount for multiple dogs.


Summary:
Highest prices for a routine dog spaying operation:
Female dog spaying 10kg - $365.
Female dog spaying 25kg - $420.
Female dog spaying 40kg - $540.

Lowest prices for a routine dog spaying operation:
Female dog spaying 10kg - $200.
Female dog spaying 25kg - $200.
Female dog spaying 40kg - $200.

You can see from this small survey that there is a huge variation in female dog spaying price and that, therefore, it pays to shop around. In this case, the difference in price would have been quite significant had you shopped around (you would have saved yourself $165 for a 10kg dog, $220 for a 25 kg dog and a massive $340 for a 40kg dog). The travel distance between the highest and lowest priced clinics was only about 5 kilometers, if that. Veterinary clinics are competitive entities and many will attempt to undercut others on price to secure you as a client.


How do vet clinics arrive at their charges?
Overall, veterinary clinics charge a lot of money for veterinary attention, surgery and medication for two main reasons: the high costs of running the practice (veterinary clinics are expensive to own and maintain) and the high costs of veterinary drugs and diagnostic equipment (drug companies charge vets a lot of money for the drugs we purchase). Staff costs are high, land rates are high, equipment costs are high and many drugs only have a certain limited shelf-life (used-by date), after which they can not be used and are therefore wasted, costing the practice money.

As a general rule, the larger, multiple-vet veterinary clinics tend to charge more for their surgical procedures and services than the smaller one to two man vet clinics do. This is often because the larger clinics have massive staffing and operational overheads that need to be met through higher charges, however, the higher costs can also sometimes be a sign of the quality of monitoring and patient care that your pet is receiving. The other reason large vet clinics tend to charge a lot more for their services is because they can. They have enough clients and reputation built up over the decades to not feel a need to compete for your business: if you can't afford their fees, they don't mind if you look elsewhere as it doesn't really affect their bottom line. On the flip side, sometimes large vet clinics will actually charge less for their routine procedures, such as dog spaying, because they benefit from economics of scale (i.e. big clinics often save a lot of money on drugs and medications and charge their clients less for them because they make such large orders with drug companies that the drug companies give them significant discounts).

In the previous price surveys that I have done (male cat and dog desexing and female cat desexing), the latter point has generally been borne out: some of the most competitive prices around have actually belonged to the very large, high-quality, multiple-vet practices that could have been expected to charge a lot more. In this survey, however, I have found the opposite. Except in cases where suburb wealth has been at the much lower end, the practices with the highest dog spaying fees have all been the much larger practices (Clinics 1, 6 and 8). Clinics 4 and 7 are also large practices, but they are charging lower fees, either due to economics of scale (which is possible) or due to the lower socioeconomics of the suburb (probably more likely). Clinic 3 is interesting because it is a tiny practice that is charging some of the highest prices - this is most likely due to the massive wealth of the suburb that it is located in.

Smaller clinics, on the other hand, do tend to charge less for their services, depending on where they are based and how much competition they have. Smaller clinics struggle to get a foothold in the market and will often have very competitive prices to get routine surgeries, such as dog spaying surgeries, through the door. The clinic with the lowest prices in my survey was a small, 1-man vet clinic (clinic 9). You should be very choosy when opting to have your pet's surgery done through a small clinic, however: whilst most small vet clinics are run by highly competent people who provide a very good standard of care, some small clinics remain small because people know not to go to them (their service might be bad, their premises unclean or their patient care and monitoring not up to scratch). As a general rule, however, most vets in big and small clinics alike have done thousands of dog spay surgeries (they're probably one of the easiest surgeries we vets can perform) and it is unlikely that you will experience a problem even if you do go to a tiny little clinic in the middle of nowhere for your services. For example, the clinic that offered the lowest-priced services in my survey ($200 for a dog spay surgery) is a small clinic, however, it is run by an excellent surgeon who performs really good work. i.e. low procedural costs and small practice size does not always equate to poor service. Interestingly, this clinic is located in a very wealthy region of Canberra (only 5 km from the most costly clinic in the survey) and could well afford to charge more than it does (the low prices in this case may be as much a function of a very generous-minded vet as anything else).

Suburb also makes a huge difference to the price of services. Clinics in affluent suburbs, be they big or small (they are often large clinics), often charge much more for their services than clinics in lower socioeconomic suburbs. Their clients can afford to pay more. In all of my surveys, to date, suburb wealth has actually been one of the most significant factors dictating the costs of desexing services. The most expensive clinic surveyed (Clinic 1) was a large, multi-vet practice located within a very rich area of Canberra, as were the second and fourth-most expensive clinics (clinics 6 and 8). Clinic 3 was only a small, one-man practice, but it could charge high fees (third highest) because it was also located within a wealthy area of Canberra (in a similar location to clinic 6).

Competition also makes a huge difference to the price of dog spaying services. Clinics in suburbs or towns that have many vet clinics often charge less for their dog spaying services than vet clinics in towns where there is little to no competition.

Costs will also be increased if your dog experiences spay complications during the surgical procedure (e.g. needs a blood transfusion during surgery) or if it has a dog spaying surgery that is more complex to perform than normal (e.g. the dog is large-breed, obese, in-heat or pregnant). Added costs will also apply if the dog needs pre-anaesthetic bloods done or if it needs additional procedures performed (e.g removal of a retained baby tooth, dewclaw removal, prophylactic gastropexy, microchipping and so on).

9b. Where and how to source low cost and discount dog spaying.
Once again, for legal reasons, I can not name the names of veterinary clinics that offer discounted and low cost neutering services. I can, however, provide tips on how and where you might find them.

1. Ring around:
For the cost of a couple of phone calls to different clinics in my area, I was able to discover that the price of dog spaying varied by as much as $340. By shopping around, you can often find lower cost veterinary clinics in and around your area. When you do shop around, don't forget to ask the clinics what additional charges might be incurred, should your dog be found to be in-heat or pregnant.

2. Don't forget to look at clinics in lower socioeconomic areas:
Just because you live in an affluent area does not mean that you have to pay affluent area prices for your vet services. There is no rule to say that just because you live in a wealthy suburb, you need to go to a vet clinic in that suburb. Try looking outside of your area. A lot of veterinary clinics in lower socioeconomic areas provide perfectly good services (certainly, most can desex a female dog with no trouble at all), but do not charge the kinds of prices that rich suburb clinics do. This was certainly borne out in my survey - the highest cost clinics were definitely the wealthy suburb clinics.

3. Consider having your dog desexed by a shelter or pet charity such as the RSPCA:
Shelters these days often have large vet clinics attached to them, with veterinarians that perform thousands of desexing surgeries every year (shelter vets probably perform far more routine animal desexings than most other GP vets would do). These charity organizations tend to charge a good deal less for their vet services than commercialized private vet clinics do and by giving these clinics your spaying business, you'll be contributing to the health and welfare of animals in the shelter. Pensioners and Centrelink recipients in particular can often receive good discounts for services at these places.

4. If you are buying a dog, consider buying your pet from a shelter, pound or pet charity such as the RSPCA:
These animals are normally sold to you already vaccinated, spayed and microchipped.

5. Have your dog spayed early - prior to its first season:
Most clinics charge more (from $50 up to $140 more) to desex a dog who is in-heat or pregnant. By getting your dog desexed early, you can avoid these additional costs. By desexing early, you will also be having your dog spayed prior to the attainment of its full adult bodyweight, which will greatly reduce the costs of having a large breed dog spayed.

6. Pay attention to what the threshold weight ranges are for dog spaying fees:
Most veterinary clinics have a series of pet weight ranges that they use when billing you for dog spaying surgery. For example:
A dog of 0-10kg may cost $300 to spay.
A dog of 10-25kg may cost $350 to spay.
A dog of 25-50kg may cost $400 to spay.
A dog of 50kg+ may cost $500 to spay.

These are not accurate costs, I am just using them as example.

If your pet is an overweight terrier that weighs in at 11kg, then you will be charged $350 to have her spayed (the same price as a 20kg Border Collie). If you can diet your pet a bit and get her weight down to just under 10kg, however, not only will she be happier and healthier for the weight loss, but she will now only cost you $300 to spay (a saving of $50).

NOTE: please do not diet your pet unsafely just to get a reduced desexing fee. You will never be able to turn a 50kg dog into a 23kg dog safely! If your pet is overweight, however, or only a few hundred grams above a dog spaying price threshold, some dieting may help you to move your pet into a marginally cheaper price range.


Alternatively, you can ring around the various clinics and find out what their weight thresholds for price actually are. They're different in most clinics.

For example, Clinic A might charge according to these weight threshold levels:
A dog of 0-10kg may cost $300 to spay.
A dog of 10-25kg may cost $350 to spay.

But, Clinic B might charge using different weight thresholds:
A dog of 0-12kg may cost $300 to spay.
A dog of 12-30kg may cost $350 to spay.

In the case of the person with the overweight 11kg terrier, that person would have to diet the pet and reduce its weight to below 10kg in order to reach the $300 dog spaying weight of clinic A. The same person would not, however, have to do anything to reach the $300 dog spaying weight of clinic B because the weight cut-off for that same price is 12kg.

9c. Free dog spaying.
It is very uncommon for any commercial veterinary clinic to ever offer their clients free dog spaying services. Spaying an animal for free is essentially a business loss to that clinic.

If you live in a place where there are active, charity-run or government-operated dog control programs going on (e.g. in India and Cambodia where street dogs and pet dogs are spayed for free to reduce population numbers and the spread of diseases such as rabies), it may be possible for you to get a pet desexed for free.







10. Alternatives to spaying your female dog:

Owners who do not elect to get their female dogs desexed often request other ways of preventing the pregnancy problems faced by their entire pets. Owners looking to prevent their dog or dogs from breeding can make use of a range of birth control (contraceptive) measures, which I have outlined in the following sections. The reality is, however, that although these alternative measures will go some way towards preventing a dog from becoming pregnant, they are not 100% effective like desexing is and they will not help to manage or prevent the behavioural and medical health problems that can occur when a female dog is left entire. Additionally, many of these alternative solutions do come with significant side effects and health risks of their own. Desexing is always the best choice.

IMPORTANT: Check your local state and regional laws before opting for any of these dog spaying alternatives. Animal population control laws are changing and increasing all the time. It may be illegal for you to keep an entire female dog on your property without a breeder's licence. Certainly where I come from (the A.C.T. - Canberra), it is illegal to keep a non-breeding-purposes dog entire without a breeding licence.


10a. Dog birth control method 1 - separate the male dog from the female dog and prevent her from roaming.
If your main concern is preventing your entire female dog/s from becoming impregnated by one of your entire males or other people's entire dogs in the neighbourhood, you can devise ways of preventing the female dog/s from physically accessing any males and from leaving your property.

This is a scenario that commercial and show dog breeders have to deal with all the time: they can't get their valuable stud males or females desexed, but they do not want them to breed ad libitum with everyone. In these situations, what breeders tend to do, and what you can do too, is house their dogs (males and females) individually in specially-constructed, escape-proof dog runs so that female dog escape and mismating (inappropriate mating and impregnation) can not occur.

Note that simply constructing a separate fenced-off yard is not enough! It needs to be escape proof and male-dog-proof and that includes putting a roof on it. Many dogs will scale massive heights and climb high fences to procreate with the opposite sex.

Just keeping the female dog locked away from the boys only while she is in heat (in season) is often no guarantee of her not falling pregnant. The reason for this is that many pet owners often can not identify accurately enough when a female dog's season starts and when it ends. Even though female dogs do generally display obvious outward physical signs of being in season (e.g. dogs usually develop a huge, swollen vulva when in season), the increase and then waning of this vulval sign alone may not 100% correlate with the timing of when the fertility-period ends (i.e. when estrous ends). For example, some dogs may continue to have a large vulva for a while after their season ends, making their owners think they are still "on", whereas other dogs may have a smaller in-heat vulva size or a vulva that reduces in size prematurely, making their owners think that they are off heat and therefore "safe to let out" when, in fact, they can still get pregnant. Some owners, unfamiliar with the normal size of their dog's vulva, may miss the vulval-enlargement-sign altogether and never realise that the dog was in heat until it becomes pregnant. Another common mistake that many inexperienced female-dog owners also make is to think that the "blood spotting period" of the dog's season is the time when she is on heat and ready for mating - it's not. The blood spotting happens during a period called "pro-oestrous", just before the animal enters estrus or true heat. The female dog is not receptive to mating and able to fall pregnant until the period after pro-estrus (i.e. after the bloody vaginal discharge stops). Owners who let their pets out into public because the "bleeding has stopped" run a huge risk of their bitch falling pregnant.

If you are going to keep your female dog entire and lock her away from the males only whilst she is in heat, then my recommendation is to have a veterinarian aid you in detecting when her heat truly starts and ends. The vet can perform weekly vaginal swabs on the dog, looking at the dog's vaginal cells to more accurately determine whether the dog is in heat or not. The vet can also perform blood estrogen and progesterone assays to determine what stage of the estrous cycle the dog is in and whether she is able to become pregnant or not if she is let out.

Even if you can manage to separate your female dog from any entire males, thereby preventing pregnancy, not desexing your female animal will do nothing for her behaviour or her health. She will still be inclined towards showing unfavorable or annoying entire-female behaviours (roaming, male-dog attraction, interdog aggression, urine marking, blood spotting etc.) and she will still be prone to a range of uterine, mammary and ovarian health problems.

The best option is to get the male and female animals in your household desexed if they are not registered breeding animals (you will be required to by law in certain states). There are important behavioural, medical and population-control benefits to be gained by having each of the canine sexes desexed.


10b. Dog birth control method 2 - neuter your male dog/s and keep your entire female dog/s inside.
If you do not want your male animal/s to impregnate the female animals in your household, you can elect to have the male dogs desexed so that the female/s will have nothing to mate with. Certainly, there are important health benefits to the male dog if he is desexed and desexing him will prevent him from wandering around your neighbourhood getting other female dogs pregnant.

Not desexing the female animal in this situation, however, will do nothing for her behaviour or her health. She will still be inclined towards showing unfavourable or annoying entire-female behaviours (roaming, male dog attraction, interdog aggression, urine marking, blood spotting etc.) and she will still be prone to developing a range of uterine and ovarian and hormone-induced health problems.

The best option is to get the male and female animals in your household desexed if they are not breeding animals (you will be required to by law in certain states). There are important behavioural, medical and population-control benefits to be gained by having each of the sexes desexed.


10c. Birth control for dogs method 3 - the dog birth control "pill" and female estrus suppression.
There are a number of ways to suppress oestrus (heat, season) in female dogs and therefore prevent them from becoming pregnant and from showing the unpleasant physical and behavioral symptoms of being in heat. Most of these solutions involve manipulating the female animal's reproductive cycle (estrous cycle) using a range of reproductive hormone and reproductive-hormone-like chemicals. Some of these contraceptive drugs include: progesterones (progestagens) and progesterone-like chemicals and testosterone and testosterone-like anabolic drugs.

The problem with many of these hormonal estrous suppression solutions is that they can have potentially devastating, life-threatening and/or aesthetically displeasing side effects.

Progesterones:
The progesterone and progesterone-derived drugs commonly used to temporarily or, with repeated use, permanently suppress estrous in the bitch include: medroxyprogesterone acetate (MPA), megestrol acetate and proligestone. Having less or fewer side effects than the testosterone-based products, progesterones are the most common drugs used for estrous suppression in the bitch. They are not, however, without certain important potential side effects.

Common side effects of progesterone use in the bitch include: lethargy (sleepiness); increased appetite; weight gain and, occasionally, loss of hair or change in hair colour and shrinkage of the subcutaneous tissues at the site of injection. Insulin resistance and diabetes mellitus may also be induced by long-term progesterone usage as can growth hormone excess problems like acromegaly (administration of artificial progesterones is one of the main causes of acromegaly in the dog). Progesterones can sometimes mimic the effect of corticosteroids in the dog, resulting in a Hyperadrenocorticism effect (Cushing's disease) and a liver condition called steroid hepatopathy (a liver full of fat).

Progesterone drugs are metabolized by the liver and should never be given to animals with liver disease.

Some bitches treated with progesterone products have been found to develop severe mammary enlargement, mammary nodules and even nasty mammary tumors (breast cancer).

In breeding animals, the use of certain oestrous-suppressing progesterone drugs has been found to result in reduced fertility for many individuals, thereby reducing the affected animals' value as breeding animals. Permanent infertility can be induced if the animal receives long term, prolonged progesterone treatments or is given progesterone prior to its first cycle (never give progesterones before the first season).

The incidence of false pregnancy (also called pseudopregnancy or phantom pregnancy) may also be increased by the use of progesterones.

Animals treated with progesterone whilst already pregnant may have delayed parturition, resulting from a failure of normal hormonal birth-induction processes (i.e. the bitch does not receive the 'signal' telling her body when to give birth). This delayed parturition results in the death and mummification of the fetuses inside the womb. These animals will often need a caesarean section to give birth. The milk production of such animals (ones given progesterone while pregnant) will also be adversely affected by the progesterone usage (the animal's milk production is inhibited by progesterone) and the live pups born by C-section may require milk supplementation and hand-rearing.

More catastrophically, the use of certain heat suppressant progesterone drugs (e.g. medroxyprogesterone acetate, repeated doses of megestrol acetate) has been shown to increase the risk of the bitch developing pyometron - a severe, life-threatening, infection and abscessation of the animal's uterus. Many bitches that develop pyometron need to be desexed to save their lives and those that are treated medically may not be able to go on to produce viable litters due to permanent uterine damage and scarring. The risk of pyometron does not seem to be as high with proligestone as it does with some of the other progestagens.

Author's note: of all of the progesterone products marketed for this purpose, proligestone (proligesterone) is considered to be one of the safer ones, with the lowest incidence of side effects. It is traded as Covinan. Megestrol acetate has more side effects, but these are not too common provided the drug is used according to instructions and not for prolonged periods of time. The use of medroxyprogesterone acetate (MPA) is not recommended at all for this purpose because it stays in the body for many months and has a high incidence of severe reproductive and mammary side effects.


Image 1: This picture is an image of the front teeth of a dog with canine acromegaly (an overproduction of canine growth hormone). The front teeth are spaced widely apart, which is abnormal. This condition, which has many adverse effects on the growth and health of female dogs, can be caused by estrus suppressing progesterone administration.
Picture 2: This is an image of the uterus of a dog that died from severe pyometron. This severe infection of the uterus can be caused by heat suppressing progesterone administration.


Testosterones:
The use of testosterone and testosterone-like products (e.g. mibolerone) to reduce cycling in the bitch is rarely done these days, the side effects often being deemed more unacceptable than those of the progesterone-type products.

Testosterones can make the female animal look and act more masculine (e.g. it may show increased muscle development and clitoral enlargement) and cause it to develop many of the same behavioural issues as the entire male animal (e.g. mounting and aggression). Testosterone-treated females are also more prone to developing many of the same testosterone-induced medical conditions - e.g. perianal adenomas - more commonly encountered in male dogs.

Testosterone-treated animals are more prone to developing liver problems (some develop jaundice) and renal disease. They are more prone to developing oily, stinky-smelling skin and various skin conditions. They sometimes develop vaginitis and vaginal discharges. Treated animals are also more likely to develop fertility problems (subfertility issues) later on.

Author's note - because testosterone-based products used in pets are similar to those used illegally in human body-building competitions and competitive sports, they are becoming more and more restricted for veterinary use because of the risk of them falling into the wrong hands. This is another reason why progesterone has overtaken testosterone for dog estrous suppression.


Because of the risk of severe, life-threatening side effects, hormonally-induced heat suppression should only be used as a very last resort and, even then, only in animals that are intended to be used as breeding animals later on (breeders need to be aware that significant loss of fertility can occur with their use as well as uterine diseases like pyometron and mammary diseases like breast cancer). It is far safer to isolate your breeding bitch from the males when it is in heat (season) than it is to try to artificially manipulate the female animal's reproductive cycle and keep heat suppressed. If breeding is not an aim for you, it is far better and safer to desex the female dog than it is to try to manipulate its reproductive cycle using hormones.

Note that, although many of the unfavorable and annoying behavioural characteristics of female dog season (e.g. roaming, male-dog attraction, interdog aggression, urine marking, blood spotting etc.) may be suppressed using these drugs (with estrus suppressed, the behaviours can not occur), the female dog will still be prone to a wide range of uterine, mammary and ovarian health problems, mentioned above.

The best option is to get the male and female animals in your household desexed if they are not breeding animals. There are important behavioural, medical and population-control benefits to be gained by having each of the sexes desexed.


10d. Dog birth control method 4 - the "male pill" - fertility suppressing implants (contraceptives) for male dogs.
Similar to the situation described in section 10b, if the male dogs in the family can be rendered infertile and the entire female dogs can be kept inside out of reach of the general public's dogs, then the female dogs should not be able to get pregnant. The male dog contraceptive pill is another way of rendering the male dog infertile without actually having to desex him.

The GnRH analogues are a group of drugs that produce a negative effect on testosterone production by exerting a negative feedback effect on the brain-derived hormone (called luteinising hormone or LH) that is responsible for stimulating the testicles to produce and release testosterone. By preventing the production of LH, the GnRH analogues essentially prevent the LH-mediated production of testosterone by the testicles.

The GnRH analogue most commonly used in Australia is deslorelin (tradenames include Suprelorin-12). It is currently being marketed as a male dog form of "the pill". It is a slow-release, 12-monthly, contraceptive implant that suppresses male testosterone production to such a low level that canine fertility, sperm production, ejaculation and libido are all but non-existent. The male animal essentially becomes infertile whilst it has the implant and is unable to father any pups.

Because of this product's inhibitory effects on canine testosterone production, it is also possible that such an implant may, in the future, play an important role in the control and management of testosterone-mediated medical and behavioural problems as well.


Image: This is Suprelorin-12, a 12-monthly slow-release implant used to reduce fertility and unwanted breeding by male dogs.

Not desexing the female animal in this situation, however, will do nothing for her behaviour or her health. She will still be inclined towards showing unfavourable or annoying entire-female behaviours (roaming, male dog attraction, interdog aggression, urine marking, blood spotting etc.) and she will still be prone to developing a range of uterine and ovarian and hormone-induced health problems.

The best option is to get the male and female animals in your household desexed if they are not breeding animals (you will be required to by law in certain states). There are important behavioural, medical and population-control benefits to be gained by having each of the sexes desexed.


10e. Canine birth control method 5 - canine vasectomy.
Similar to the situation described in section 10b, if the male dogs in the family can be rendered infertile and the entire female dogs can be kept inside out of reach of the general public's dogs, then the female dogs should not be able to get pregnant. The male dog vasectomy surgery is another way of rendering the male dog infertile without actually having to desex him.

If all you desire is that your male dog not be able to breed with any females inside of or outside of your home, then canine vasectomy is an option for you. Vasectomy is the surgical removal of a section of the male animal's vas deferens or spermatic duct (the tube that takes the sperm from the testicle where it is made, to the lower reproductive tract regions of the prostate and urethra). Without this section of piping, the sperm can not reach the animal's urethra and penis and the animal, therefore, can not get anything impregnated.

Vasectomy is certainly effective at stopping breeding and the passing on of defective genes to any offspring. It will not, however, do anything for that male animal's behaviour or health. Because the testicles are left intact during vasectomy, the animal will still have plenty of testosterone in its body. He will therefore still be inclined towards showing unfavourable male-animal behaviours (roaming, aggression, dominance, territory marking, mounting and copulating with females etc.) and he will still be prone to developing a range of prostatic, testicular and testosterone-mediated health problems.

Author's note: vasectomy is not instantaneous. A vasectomised dog will still be fertile and capable of impregnating bitches for 3 weeks following the procedure. The vasectomised dog should be evaluated by a vet prior to the reintroduction of the dog to any females to ensure that his semen contains no sperm (i.e. that the procedure has been effective).

Not desexing the female animal in this situation, however, will do nothing for her behaviour or her health. She will still be inclined towards showing unfavourable or annoying entire-female behaviours (roaming, male dog attraction, interdog aggression, urine marking, blood spotting etc.) and she will still be prone to developing a range of uterine and ovarian and hormone-induced health problems. The vasectomised male dog will still be attracted to her when she is in heat and mating will occur between them (though no pregnancy should result).

The best option is to get the male and female animals in your household desexed if they are not breeding animals (you will be required to by law in certain states). There are important behavioural, medical and population-control benefits to be gained by having each of the sexes desexed.

To go from this Spaying a Dog page to the Pet Informed Homepage, click here.

To go to our photographic, step-by-step, cat desexing page, click here.

To go to our photographic, step-by-step, pregnant cat spay page, click here.







References and Suggested Readings:

1) Induced Abortion, Pregnancy Prevention and Termination, and Mismating. In Feldman EC and Nelson RW: Canine and Feline Endocrinology and Reproduction, 2nd ed. Sydney, 1996, WB Saunders Company.

2) Surgery of the Reproductive and Genital Systems. In Fossum TW, et al, editors: Small Animal Surgery. Sydney, 1997, Mosby.

3) Canine Reproduction. In Daris W, editor: Compendium of Animal Reproduction, 5th ed. 1998, Intervet.

4) Kustritz MVR, Olson PN, Early Spey and Neuter. In Ettinger SJ, Feldman EC, editors: Textbook of Veterinary Internal Medicine, Sydney, 2000, WB Saunders Company.

5) Verstegen J, Contraception and Pregnancy Termination. In Ettinger SJ, Feldman EC, editors: Textbook of Veterinary Internal Medicine, Sydney, 2000, WB Saunders Company.

6) Kustritz MVR, Klausner JS, Prostatic Diseases. In Ettinger SJ, Feldman EC, editors: Textbook of Veterinary Internal Medicine, Sydney, 2000, WB Saunders Company.

7) Davidson AP, Birth Control Alternatives. In Ettinger SJ, Feldman EC, editors: Textbook of Veterinary Internal Medicine, Sydney, 2000, WB Saunders Company.

8) Johnson CA Disorders of the Estrous Cycle. In Nelson RW, Couto CG, editors: Small Animal Internal Medicine, Sydney, 1998, Mosby.

9) Johnson CA Disorders of the Vagina and Uterus. In Nelson RW, Couto CG, editors: Small Animal Internal Medicine, Sydney, 1998, Mosby.

10) The Pelvis and Reproductive Organs of the Carnivores. In Dyce KM, Sack WO, Wensing CJG editors: Textbook of Veterinary Anatomy, 2nd ed. Sydney, 1996, WB Saunders Company.

11) Verstegen J, Feline Reproduction. In Ettinger SJ, Feldman EC, editors: Textbook of Veterinary Internal Medicine, Sydney, 2000, WB Saunders Company.

12) Feline Reproduction. In Feldman EC and Nelson RW: Canine and Feline Endocrinology and Reproduction, 2nd ed. Sydney, 1996, WB Saunders Company.

13) Rijinberk A, Acromegaly. In Ettinger SJ, Feldman EC, editors: Textbook of Veterinary Internal Medicine, Sydney, 2000, WB Saunders Company.

14) Overall KL, Aggression: Triggers, Flashpoints and Diagnoses. In Post Graduate Foundation, Aint Misbehaving, Sydney, 2001, Post Graduate Foundation in Veterinary Science, University of Sydney, Proceedings 340.

15) Infertility, Breeding Disorders and Disorders of Sexual Development. In Feldman EC and Nelson RW: Canine and Feline Endocrinology and Reproduction, 2nd ed. Sydney, 1996, WB Saunders Company.

16) Periparturient Diseases. In Feldman EC and Nelson RW: Canine and Feline Endocrinology and Reproduction, 2nd ed. Sydney, 1996, WB Saunders Company.

17) Johnson CA Disorders of the Mammary Gland. In Nelson RW, Couto CG, editors: Small Animal Internal Medicine, Sydney, 1998, Mosby.

18) Linde-Forsberg C and Eneroth A, Abnormalities in Pregnancy, Parturition and the Periparturient Period. In Ettinger SJ, Feldman EC, editors: Textbook of Veterinary Internal Medicine, Sydney, 2000, WB Saunders Company.

19) Memon MA, Mickelsen WD, Inherited and Congenital Disorders of the Male and Female Reproductive Systems. In Ettinger SJ, Feldman EC, editors: Textbook of Veterinary Internal Medicine, Sydney, 2000, WB Saunders Company.

20) Knapp DW, et al. Tumors of Urogenital System and Mammary Glands. In Ettinger SJ, Feldman EC, editors: Textbook of Veterinary Internal Medicine, Sydney, 2000, WB Saunders Company.

21) Overall KL, Myths and Legends in Animal Behaviour: From the Past and Present. In Post Graduate Foundation, Aint Misbehaving, Sydney, 2001, Post Graduate Foundation in Veterinary Science, University of Sydney, Proceedings 340.

22) Schaefers-Okkens AC, Estrous Cycle and Breeding Management of the Healthy Bitch. In Ettinger SJ, Feldman EC, editors: Textbook of Veterinary Internal Medicine, Sydney, 2000, WB Saunders Company.

23) Davidson AP and Feldman EC, Ovarian and Estrous Cycle Abnormalities. In Ettinger SJ, Feldman EC, editors: Textbook of Veterinary Internal Medicine, Sydney, 2000, WB Saunders Company.

Pet Informed is not in any way affiliated with any of the companies or clinics whose products appear in images or information contained within this article. The images, taken by Pet Informed, are only used in order to illustrate certain points being made in the article.

Copyright May 21st, 2009, www.pet-informed-veterinary-advice-online.com.
All rights reserved, protected under Australian copyright. No images or graphics on this Pet Informed website may be used without written permission of their owner, Dr. O'Meara.

MPA-50 and Neocort are registered trademarks of Ilium Veterinary Products.
Neotopic H Lotion is a registered trademark of Delvet Pty Ltd.
Covinan and Caninsulin are registered trademarks of Intervet Australia.
Rimadyl is a registered trademark of Pfizer Animal Health.
Ovarid, Prolet and Tardak are registered trademarks of Jurox Pty Ltd.
Previcox is a registered trademark of Merial Australia Pty Ltd.
Metacam is a registered trademark of Boehringer Ingelheim Pty Ltd.
Prescription Diet Canine i/d is a registered trademark of Hill's Pet Nutrition Pty Ltd.
Royal Canin Digestive Low Fat is a registered trademark of Royal Canin.
Carprofen tablets and Stilbestrol tablets are registered trademarks of Apex.
Wound-Gard is a registered trademark of Allerderm.
Suprelorin 12 is a registered trademark of Peptech Animal Health.

Please note: the desexing information provided on this page contains general recommendations and medical advice only. The information provided is based on published information; relevant veterinary literature and publications and my own experience as a practicing veterinarian. The advice given is appropriate to the vast majority of pet owners, however, owners with pets should still take it upon themselves to ask their own veterinarian for further advice on animal sterilisation and dog spaying. Owners with specific circumstances (breeding dogs, showing dogs, stud dogs, breeding businesses, aggressive bitches, incontinent dogs, immaturely-developed dogs, those whose dogs have hormone-mediated medical or behavioural issues, those seeking to control estrus artificially in breeding/showing bitches etc.) should ask their vet what the safest and most effective protocol is for their situation.

Any dose rates mentioned on these pages should be confirmed by a vet. Dosing rates for common drugs are being changed and updated all the time (e.g. as new research comes in and as drug formulations change) and information here may not remain current for long. What's more, although we try very hard to maintain the accuracy of our information, typos and oversights do occur. Please check with your vet before dosing any pet any medication or drug.



Common misspellings and spelling variants: nuter, nutered, nutering, oestrous, oestrus, estrus, estrous, oestris, estris, diestrus, dioestrus, diestrous, dioestrous, diestris, dioestrous, interestrus, interoestrus, interestrous, interoestrous, interestris, interoestrous, anestrus, anoestrus, anestrous, anoestrous, anestris, anoestrous, pup, puppy, puppys, puppies, bicth.

Alternative, including slang, synonyms for desexing: nut, nutting, nutted, the snip, the chop, castrate, castrating, castrationing, castration, gonadectomy, sterilisation, sterilising, sterilised, sterilization, sterilizing, sterilized, neutered, neutering, neuter, fix, fixed, fixing, desex, desexing.