I have long thought that a large amount of what veterinarians do is cleaning up genetic messes brought about by generations of breeding for a particular look, with nary a thought for function. Nowhere is this more apparent than in the curious world of the brachycephalics – the snub-nosed breeds like pugs, bulldogs and the like.
Before I go down that snorty and slobbery path, though, I want to make a disclaimer: I’m not making any disparaging remarks about the inherent goodness, worthiness or niceness of any breed of dog. I’m a former pug owner (I grew up with a wee pug named Betsy who was as sweet as the day is long) and I have known many a wonderful and mild mannered bulldog in my years of practice.
In terms of disposition, you’d be hard pressed to find a disagreeable bulldog. I’m only talking about certain physical features that make them prone to some serious medical issues in particular circumstances. These are baked-in features that have been developed and honed into a potentially lethal constellation of anatomical abnormalities by the selection of form over function for so long that they are now breed standards.
With the words above about their sunshiny disposition firmly in mind, let’s take the English bulldog as a prime example of what veterinarians call the brachycephalic airway syndrome. Long ago, bulldogs were bred for a particular use – bull baiting, or (in essence) bull wrestling. Short, stocky and gifted with uber-strong jaws, the task of the ancestral bulldog was to bring a bull to its knees for sport. (If I was giving this as a lecture I’d surely throw some air quotes, or as I like to call them, "air quotes" around that last word). Their physical form made sense for what they were intended to do, all morality decisions about torturing bulls aside.
But as man became ever-so-slightly more civilized, the sport of bull baiting went the way of goldfish swallowing and fanny packs and died out (mostly – I think there’s still a bull baiting pocket amongst the hipsters of Brooklyn, where they sip Pabst Blue Ribbon and compare beards and levels of postmodern angst. Also, a brick of tofu is substituted for the bull).
So the need for bulldogs to have a certain physical form to get the job done faded as well. But people had taken a liking to the stocky little guys and the demand for bulldogs didn’t die out like the sport of bull baiting did; people wanted more of them. Breeding practices, intended to meet the demand for bulldogs with a supply of wrinkly little bulldog puppies (as long as I live, I will never see anything as cute as a bulldog puppy) switched from "make me a dog that can bring down a bull" to "make me a dog that looks just like that one!" and the need for form to follow function was uncoupled.
Somewhere in all this, a bulldog that looked like the archetypal bulldog was begat, except for one thing: this bulldog was born with a small (or hypoplastic) trachea. Instead of a normal windpipe, his was narrower – about the size of a cat’s. Hard to bring down a bull if you’re breathing through a coffee stirrer, but all this little guy had to do was look good. And he was bred. Again and again. His beautiful bulldog looks were so briskly beguiling that his genes were in high demand, no matter the size of his trachea. It only became apparent that a hypoplastic trachea was a problem after he was older and had already sired several generations of adorable, wrinkly, pink-nosed, mewling litters of bulldogs, each one with a tiny and inefficient trachea of their very own. But by then, it was too late; his toxic DNA had been let loose on the world and the genie refused to go back in the bottle.
Bulldogs can be considered the original genetically modified organism.
To add to all the genetic fun, the trachea’s not the only thing that’s amiss. To go along with the wee windpipe, they are bestowed with overly small nostrils, a soft palate that flaps like a pennant in the breeze (and actually can go down the windpipe in severe cases) and the pleasant-sounding "everted laryngeal saccules." You know that little bag of giblets that comes inside your average roasting chicken? Stuff that into a tiny bulldog trachea, and you have a fair approximation of just what an everted laryngeal saccule is: little gobbets of flesh that normally don’t go into the windpipe that, in the case of the bulldog, do. It’s like Mother Nature finished designing the hypoplastic trachea, stepped back a bit to have a look and said "Nope, still too big. Hand me those giblets over there – we’ll throw those in.”
What does all this mean for the modern bulldog? They’d be better off baiting bulls. At rest, or watching Golden Girls from the comfort of the couch, they do just fine. They can breathe through all that meaty mess with no problem in an air-conditioned environment when they are at rest. But if the humidity and the temperature rise, or they become active, or all of that stuff happens at the same time, well...that’s where things go all whoopsy.
Dogs regulate their body temperature largely by panting. They lack the ability to efficiently dump heat by sweating as most other mammals do. (Thanks again, Mother Nature!) A hot bulldog is a bulldog in trouble. They have to dump excess heat by blowing it out through that tiny little coffee stirrer of a trachea, and to move all that air through the resistance of a hypoplastic trachea requires muscle energy. And a lot of muscle energy generates...heat. I think you can see the outlines of the problem forming here; the very act that they use to cool down makes them hotter. It’s a vicious positive feedback loop that can get exponentially worse in just a few minutes. To break the cycle, we have to step in medically, knock them out, actively cool them and place a breathing tube.
I have personally done this scores of times, including for one frequent flyer named Mr. Beefy, who I could count on seeing in my ER on the first warm day of spring every year. His owners never seemed to learn. Luckily, Mr. Beefy bounced back from the sedation and intubation and seemed to say “Where’s that bull – lemme at him!” after each episode. But had I not been there to break the cycle, it surely would have resulted in his demise.
Mother Nature has been getting bad rap up to this point, and the truth is she’s not to blame in this case. Like many a modern malady from carpal tunnel to black lung, this one is squarely the fault of the hairless bipedal hominid known as Homo sapiens. Sapiens is Latin for wise, and in this case, I’m not so sure that’s an apt moniker. The Greek word moros (μωρός), or fool, probably comes a little closer to hitting the mark – it’s the root of the word "sophomore," or wise fool. Homo moros and unscrupulous breeding practices have taken the basically good bulldog clay and shaped it into a creature so currently unfit for life that it can’t even bear young naturally - most bulldogs are born by caesarian section.
Natural selection rewards efficient and utilitarian design with the opportunity to reproduce and pass on those traits that aid survival to the next generation. Maladaptive traits tend to get weeded out by sharks, honey badgers, bears, and the like. Artificial selection of the kind practiced by Homo moros means that you can pass on horribly cumbersome traits, like a hypoplastic trachea, just fine as long as you look the way you should. It’s like some sort of macabre beauty contest dreamed up by Salvador Dali after an absinthe binge.
I don’t have an answer. Actually, I do, but it’ll never play in Peoria: if you’re going to breed a dog, don’t just go for looks. Go for healthy. Screw brachycephalic breed standards that say ridiculous things like in profile, the face is flat. When viewed from the side, the chin, nose leather and brow all lie in one plane, which slants very slightly backward from chin to forehead. The English Bulldog's standard says "The face, measured from the front of the cheekbone to the tip of the nose, should be extremely short, the muzzle being very short, broad, turned upward and very deep from the corner of the eye to the corner of the mouth." I don’t know about you, but I like my nose leather to stick out a little bit.
It’s easier to breathe that way.
August 12, 2014
August 12, 2014
August 4, 2014
Dr. Tony Johnson
August 4, 2014
Jessica Hekman, DVM, MS
August 4, 2014
VIN News Service commentaries are opinion pieces presenting insights, personal experiences and/or perspectives on topical issues by members of the veterinary community. To submit a commentary for consideration, email firstname.lastname@example.org.