Saturday, October 29, 2016

Spay Day

This November 2 the Manitoba Veterinary Medical Association is sponsoring "Spay Day". Assuming the Hudson Bay Company's lawyers remain quiet the event will feature significant discounts on spaying and neutering at participating clinics.

I've written about neutering before ( Spay Day is the perfect opportunity to address the other half. Let's start with that weird word, "spay". It's made a long journey from the Latin "spatha", meaning broad sword (kind of alarming...), and from which we also get spade and spatula, to the Old French "espeer", meaning to cut with a blade, and then over to England where it turns up as "spaier and spaied" and where things get... weird. There it was first used to describe a specific way of dispatching a deer with a thin blade during the hunt, but in 1410 there also is reference to "oon spaied biche lesteth lengere in hure bounte than other ii that byn not spaied". How they managed to "spaied" the "biche" and have her survive in 1410 is unclear, but henceforth the word was associated with the removal of ovaries from prized hunting dogs, and from which the evolution to the modern usage is obvious.

I'm sorry, that's probably way more than you wanted to know about that, but I was on a roll. In any case, yes, it's a weird word.

The technical term is clearer though: ovariohysterectomy. How is that clear? Just break it down: ovario = ovaries, hyster = uterus (ok, that bit's not clear) and ectomy = removal. In fact, this may be a useful thing to know. Any surgery ending in the suffix "ectomy" involves removing something. So when your own doctor starts saying blahblahectomy, pay close attention. For the record, the suffix "otomy" means making a temporary hole somewhere and "ostomy" means making a permanent or semi-permanent hole somewhere. Come to think of it, you should probably also tune in when the doctor says blahblahostomy...

Now that I've squandered half the post on terminology, let's move on to something useful - questions I have been asked about spaying.

The big one: I won't let my dog out to get pregnant, so why spay?
We have a saying, "all pets get spayed, it's just a question of whether it's an elective or an emergency procedure." This is because of something called pyometra. People will sometimes argue that they do not want to spay because it is "unnatural", forgetting that what nature intends is for the animal to become pregnant with every cycle. When this does not happen and they unnaturally cycle "empty" there is a significant risk that the open cervix and waiting uterine bed will invite bacteria in, causing a life threatening pyometra infection. According to one study 23% of intact female dogs under the age of 10 develop pyometra. The rate goes up quickly over the age of 10.

Ok, got it, but why not just a hysterectomy?
To begin with, it's not any easier or quicker as the ovaries are right there by the uterus anyway and while it would be just as effective in preventing pregnancy, leaving the ovaries behind would allow her to continue to have heat cycles. And why is this a problem? In dogs this is a problem because 12 to 16% of dogs who have gone through a heat cycle will develop mammary (breast) cancer whereas almost no dogs who are spayed before the first heat develop this. Many of these are benign cancers, but they still require surgery, often many surgeries, and some are malignant. In cats it's even worse as 90% of mammary tumours are malignant. Moreover, anyone who is thinking about leaving the ovaries in their cat has not spent quality time in the company of a cat in heat.

Yeah, but what about the risks?
There is always some statistical level of risk with any surgery and general anesthetic, but this is an extremely routine and safe procedure in veterinary medicine. In the 26 years I have been in practice I cannot recall seeing a single death related to a spay. That's not to say that it can't happen, but the risk of death due to pyometra and mammary tumours are an order of magnitude higher.

But what about these longer term knee joint risks I've been reading about?
Clever you. Nothing in the world or in life gets any simpler with time, does it? Everything becomes more complex. Yes, in the last few years more evidence has come to light linking early spaying in some breeds with an elevated risk of tearing the cruciate ligament in the knee (called the ACL in humans). What is meant by early and how much is the risk elevated? I'm going to be a wimp and tell you to ask your veterinarian. This really does have to be addressed case by case as a number of factors come into play.

So, mark it in your calendar: Manitoba Spay Day, November 2, 2016. I suspect most of you reading this have pets who are already spayed, so use that day to congratulate them on their spayedness.

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