Tuesday, December 11, 2012

Spaying saves lives.

It's incredible how much something as seemingly simple as the recommendation for spaying female dogs can become a controversial issue.  

Last night I received a patient on emergency for evaluation of difficulty breathing.  She was 12 years old, and a large mass was present in association with her mammary gland.  The clients approved radiographs (x-rays) of her chest, and unfortunately the result was catastrophic - she had widespread cancer throughout her chest.  Unfortunately, at this stage, there was no therapy that could help my patient, and her family was forced to say goodbye.

What could have prevented the development of mammary cancer? The common spay procedure (medically known as ovariohysterectomy), if performed prior to the first heat cycle, reduces the risk of mammary cancer to nearly zero percent.  Incredibly, dogs who are allowed to have more than one heat have a risk of almost 1 in 4.   Up to half of these cancers are treatable, but the other 50% may not be curable even with aggressive care.  As with any medical conditions, PREVENTION is always better than treatment.   You can read more about mammary cancer in dogs here.  Spay also prevents ovarian and uterine cancer as these organs are removed and obviously cannot develop cancer if they are no longer left in the patient.

What other reasons do you need to spay your dog? More? Sure! I have plenty more!

You may recall my post, titled "Happy Freaking Fourth of July."   Across the country, veterinarians witness thousands of cases of unwanted pregnancies in dogs and cats every year.  In the "best" case scenario, puppies are delivered easily, with no medical intervention.  These puppies add to the pet overpopulation problem and many end up in shelters, roaming, or being euthanized due to lack of a forever home.  In the worst case scenario, as in the story above, the female has difficulty delivering the puppies, requiring either emergency c-section and putting the mother's life at risk.   Each and every time I talk to a client who doesn't want to spay their dog or cat, they think they can keep their female away from a male while she is in heat - but biology is a powerful thing.  The male cat or dog's drive to find female dogs in heat and the female cat or dog's biological drive to be bred are instinctual - and the only 100% error proof way to prevent these tragic situations is by spaying your dog or cat.    

  (I've even had a client with both an unspayed female and an un-neutered male living in the SAME household tell me that she didn't think the female would get pregnant because the dogs were littermates and "they wouldn't want to do that".  Sorry, but dogs don't have social stigma or logic - they just have instincts and hormones).

Reason #3: Pyometra prevention

So, if your unspayed female dog is lucky enough that she doesn't accidentally experience pregnancy, and doesn't develop mammary cancer, what other risks of illness could she possibly have?

Another life-threatening disease of female dogs is pyometra; or infection of the entire uterus.  Each time a female dog cycles, the lining of her uterus changes. Over time, the lining can harbor bacteria, and result in a uterus that is enlarged and actually full of pus (disgusting!).  If left untreated, the bacteria spread throughout the bloodstream, causing kidney failure and severe metabolic derangments.  The only treatment for pyometra is a spay surgery; although these patients are much older, usually very sick, and with a uterus full of pus, the surgery has many more risks than a spay on a young dog.  This condition is 100% preventable.  You can read more here.

It seems pretty obvious - spay your dog (or cat) before her first heat cycle, and remove her risk of mammary cancer, ovarian cancer, uterine cancer, life threatening uterine infections, and unwanted litters, and also help prevent puppies and kittens from being euthanized or living their lives alone in a shelter.

Questions? Any theories you've heard why NOT to spay your dog? Ask me in the comments!



  1. What about the canine athlete? I have been told that waiting to spay an agility prospect until about 2 years is better for bones and joints. Truth or Hooey?

  2. First of all, I am in favor of spaying, for all of your stated reasons.
    In some countries however, I think that it is believed (by the veterinary profession) that spaying before the first heat increases the risk of bitch incontinance. So despite the increased risk of breast cancer, they wait until after the first heat.
    I wonder if there are any studies about this? When we looked, a few years ago, we didn't find any.
    I think it is clear that, on balance, it is a health benefit to spay bitches.
    I believe however, that recent research has shown that for males, on balance, neutering is less healthy. Of course, there are also behavioral considerations with intact males.

  3. By the way, in some breeds, the changes to the coat quality can be very striking (fading, poor quality) in a spayed bitch. Neutered males also sometimes.

  4. Spaying can result in estrogen related urinary incontinence in some dogs, however this is not a life-threatening issue and is easily treated with once-a-day medications if it should develop. Out of the thousands of dogs I see every year, only a handful experience incontinence - and there isn't a lot of actual proof as to if the timing matters. One study indicated that dogs spayed within the last three years had a higher incidence - suggesting that older age spay still can result in incontinence.

    Cancer kills.

  5. Regarding the canine athlete - again, no specific proof, but most would suggest waiting until 6 months for females (which is still prior to first heat).

    I purposefully did not address castration, which is less of a clear health benefit for each dog (although still reducing prostate cancer and testicular cancer incidence), and more of a benefit for behavior, roaming and population control. Many would recommend waiting until 1 year of age to castrate large breed dogs as they do not have the increased risk of mammary cancer.

  6. I disagree regarding coat color. Show proof?

  7. I agree about the incontinence thing, no real proof either way and not a very common condition despite what people would like to believe. As far as the canine athlete I have not seen enough proof of anything to dissuade me from spaying my dog young, and I do agility.

    On the male side, while there may be some debate I know an agility competitor who left her beloved male dog intact because she thought it would be better for him. He got perineal hernias and died from post-op complications. A unique case for sure but was it worth it? I would certainly neuter my dog, for a number of reasons.

    Thanks for a good "pro-spay" post!

  8. Our 12 year old lab/shepard mix has urinary incontinence and has successfully been on medication for 6 or 7 years. It's just part of our routine to mix it in her food. She was a shelter puppy, shouldn't have and never did have pups, we never had male suitors visiting from who knows where, and I never had to deal with the mess of heat (nasty!). Her incontinence is minor compared to having to try to put up with an intact female dog for 12+ years IF it was even caused by her spay surgery.

  9. This was interesting to read for me, because I did not know that "spay" actually refers to an ovariohysterectomy.
    I come from Switzerland and here, the standard spay procedure is just an ovariectomy, leaving the uterus in the body.
    Do you per chance know why there is this difference?

  10. Great question jackie!

    There's a bit of controversy in the veterinary world over which procedure is better. Europeans (apparently) have been doing ovariectomy for some time, while Americans are recommending and performing ovariohysterectomy (OHE).

    Proponents of removing overies and uterus believe(OHE) that there's no benefit to leaving it behind, and that the uterus serves only as a risk for infection, cancer, or other complications. Proponents of removing only the ovaries feel that the procedure is faster, although this really depends upon the surgeon. A recent study showed no significant difference in surgical time for OHE vs OH.

    what's better? The standard "spay" in the US is still an ovariohysterectomy by a long shot. You can find specialists and experts on both sides of the issue, but at this time, OHE is the predominant recommendation in the US.