Monday, April 18, 2016

That Distemperment Shot

You don't have to be in practice very long before you have someone come in with an out of control puppy, expressing relief that the puppy is about to get his "distemperment shot".
"He's getting that distemperment shot today, right doc? I can't wait until he settles down..."
"Um... yeah..."

To be fair it is an odd and confusing name. Its origins reach back to before the advent of modern medicine. Before the mid 19th century the prevailing theory was that good health resulted from a balance between the four "humors", also called "tempers": blood, yellow bile, black bile and phlegm. You can still see it in the language today - melancholy is Greek for black bile and indeed depressed people were thought to suffer from an imbalance of the humors with an excess of black bile. (For the record, actual bile is a greenish yellow, but you probably already knew that.) Dogs stricken with distemper were so profoundly ill and could potentially spew phlegm, bile and blood (in the stool), so they were though to be dis-tempered.

And what is it actually? Distemper is a disease caused by a virus that is related to the human measles virus, although the symptoms are very different. Dogs with distemper often have a constellation of symptoms including fever, heavy nasal discharge, breathing difficulties, vomiting, diarrhea, blindness and eventually nervous system symptoms up to and including seizures in some cases. It is spread through the discharge from a sick dog. The incubation period is up to about five days between exposure and first symptoms. There is no specific treatment, only supportive care which often has to be quite intensive to prevent the patient from succumbing and even so, about half of infected dogs will die.

Confusingly, "feline distemper", more correctly called panleukopenia, is not related to canine distemper. It is in fact a close cousin of canine parvo virus.

Incidentally though, canine distemper can also spread to wildlife. Foxes, coyotes and wolves are definitely susceptible and a mutated form has spread to seals as well where it has devastated some populations. Oddly, some marsupials are also vulnerable and distemper is theorized to have played a role in the extinction of the magnificent Tasmanian Tiger (also called the Thylacine).

That's all the bad news, but the good news is that the vaccines are extremely effective and safe. Consequently distemper is now very rare in areas where vaccination is common, such as here in the city. When we do see cases it is usually in puppies from remote communities. In the Arctic and in isolated First Nations communities it is still rampant.

Actually, I lied. That wasn't all the bad news. There is a worrying trend among some pet owners to refuse vaccination. How often to booster is a subject of some legitimate debate, but not to vaccinate at all is foolhardy (to be polite). It is still a small minority and fortunately their pets are protected by the fact that the majority of their neighbours are more sensible and responsible, so the virus cannot yet gain a foothold, but this could change. On the humans side whooping cough outbreaks are beginning to become more frequent in areas where vaccination rates are dropping. Whooping cough is sometimes fatal in babies.

Distemper is not just sometimes fatal.

And training is the remedy for "distemperment". Now, if we had a shot for that...

Monday, April 4, 2016

The Wild Boreal Chihuahua

By far and away the two most common questions I am asked by new puppy owners are "how big will he get?" and "what breed is he?". These are not subjects we are taught in veterinary school and although with experience our educated guesses improve, they are still just educated guesses. The frustrating part is that some clients judge our overall skill and knowledge as veterinarians based on these guesses and it can take years to live down a bad one. Consequently I've honed the art of being vague while sounding knowledgeable.

The question of breed guessing came to mind the other day when my own DNA test results came in. My wife had given me a "23 And Me" analysis as a gift and one of the findings was that I am 3.2% Neanderthal, which puts me in the 99th percentile of all people tested. I like to think that nobody would have guessed this, but my wife disagrees.

A similar test exists for dogs and I have had numerous clients over the years test their mixed breed dogs, perhaps frustrated by my knowledgeable vagueness.

The most popular of these tests purports to identify a truly astonishing range of breeds, from Affenpinscher to Yorkshire Terrier, including such oddities as Bergamasco, Glen of Imaal Terrier and Xolitzcuintli. I cannot vouch for the accuracy of this apparent extreme specificity and in fact, at the risk of hearing from someone's lawyer, I will confess to a tiny bit of skepticism. In contrast, for the majority of my DNA "23 And Me" is only willing to express confidence that it is generically "European", despite the fact that most of my known ancestors, back 13 generations in some cases, are German. But back to dog breeds I can say that despite the impressive list, the tests are missing one type and that that gap trips people up here, and I suspect throughout western and northern Canada.

For example, Mr. Jackson came in the other day with Bruiser, a 120 lb mound of muscle and fur that eats squirrels for lunch and begs to go outside when it's -40C. Mr. Jackson was perplexed because Bruiser's DNA breed test marked him as having a lot of Chihuahua. Bruiser resembles a Chihuahua the same way Mike Tyson resembles me.

So here's the thing.

The thing is that many of our clients get their dogs from shelters and the shelters here are full of dogs from remote First Nations communities in the north. So, am I saying that the northern Manitoba bush is seething with packs of wild boreal Chihuahuas? No. What I am saying is that when the indigenous people came to North America across the Bering land bridge around 15,000 years ago they brought dogs with them. These dogs are not any particular breed, they are simply, and beautifully I might add, "dogs". The Aztecs began breeding these dogs into a specific line that became what we now know as Chihuahuas. The DNA test then sometimes picks this up as the closest match for Bruiser and his friends. Look carefully at the next Chihuahua you see and take note of the curled tail. The other breeds with curled tales are all northern breeds in the family group sometimes called the Spitz type. Other members of this group are Chows and Akitas, who's DNA  sometimes also cross-reacts with our reserve dogs.

Fortunately for Mr. Jackson's ego Bruiser's test also highlighted husky and lab. Chihuahuas are actually very tough, but they do have an image problem with some people. Especially people who name their dog Bruiser.

I have a lot more to say about purebreds, crossbreds, mixed breeds etc., but I'll save that for another day.