There are two big problems facing purebred dogs today: health conditions that are exacerbated and exposed through inbreeding and health problems that are the result of conformation.
When we complain about the health of purebred dogs, as we often do on these sorts of blogs, there is a tendency to mix the two types of problems, but there is certain amount of error that comes from doing so. The dachshund’s back issues are not caused by inbreeding, and the Italian greyhound’s autoimmune problems are not the result of selecting for a particular body type. The former’s problems come from breeding for such a long back on a dog with such short legs, and the iggie’s immune system problems come from very tight breeding at their foundation,.
It is very important that we keep these two types of purebred dog health problem distinct. The solutions for each type are very different. In the dachshund’s case, all we’d have to do is start breeding for more leg, which already exists in the working population of the breed. In the Italian greyhound’s case, we’d have to do an outcross to increase heterozygosity in its DLA/MHC genes. That means that we’d have to cross one with a whippet or maybe a miniature pinscher to correct the problem.
But there are some breeds that actually have both problems. Yes, some breeds are unlucky to have both compromised genetic diversity and extreme conformation issues that prevent them from having optimal health.
Perhaps the most common breed to suffer from both these sorts of problems is the pug. Pugs are a very popular toy breed these days, and the dogs do have a lot going for them. They tend to have fairly stable temperaments, though they are known for being stubborn and sly. They are not border collies that require tons of exercise and mental stimulation. They can live nicely in an apartment without wrecking it, and they normally are not snappy little dogs, which means they could be a choice for an urban family.
And did I mention they do have rather distinguished looks. Some people think they are quite ugly, but they do have a sort of monkeyesque cuteness that also has tendency to humanize them. Its their tendency to look like little monkeys or, dare I say it, human babies that draws people to this breed. More so than perhaps any other breed, the pug is the one that gets dressed up in little costumes and photographed for memes on the internet.
The most obvious problem pugs face is actually the result of that monkey mug.
Pugs were always brachycephalic dogs. It is one of their distinguishing features, and almost all dogs are brachycephalic when compared to wolves and other wild canids. We need to be a little bit careful in condemning shorter muzzles, because it is possible for a dog to have a shorter than normal muzzle and have no health problems.
The problem is in extreme brachycephaly.
And this is precisely the problem that pugs exhibit.
We’ve bred them so brachycephalic that the dogs now have upper respiratory systems that are entirely stenotic– “scrunched up.” Many individuals have an elongated soft-palate, which is the fleshy bit that runs from the back of the roof of the mouth into the throat. Pugs have undergone such a rapid transformation into extremely flat-faced dogs that they often still retain a normal dog’s soft palate, which winds up become a real hindrance to the upper respiratory system. The tissue winds up blocking the airway at times, making breathing that much more difficult. The nasal passages are often similarly scrunched up, making it very difficult for the dog to oxygenate itself fully. Many pugs will not sleep with their heads down, because if they put their heads in a prone position, the respiratory system becomes blocked. Dogs breathe through their noses, and if the nostrils are squashed in, they are going to have a very hard time breathing.
Now, if that weren’t bad enough, dog use their respiratory systems as their primary method of thermoregulation. Dogs pant to cool themselves. They pass air overt their moist mucus membranes, which causes evaporation on those membranes, which then cools the dog. When pugs cannot pass air over their mucus membranes efficiently, they cannot cool themselves. Furthermore, the muzzle in domestic dogs contains a cavity that is vital in passing air through the respiratory system during panting. In pugs, that cavity is extremely reduced.
The problems with the respiratory/thermoregulation system in pugs are just the most severe. Pugs still have the same number of teeth that all other dogs have. However, when the teeth come in, there is often not enough room for them in the mouth, and the teeth have to be pulled.
And that cute little skin fold above the muzzle is actually just excess skin. The pug evolved its extreme brachcephaly very rapidly, so it often still has a bit of excess skin that normally would be stretched out over a longer muzzle. That fold is just above the dog’s nose. Dogs have wet noses,and they do produce a bit of snot. That snot winds up getting gummed up into that skin fold, and if it’s not cleaned regularly, it can be a haven for bacteria, making infections rather commonplace.
The short muzzle also exposes the eyes to injury, which are bred so they will appear somewhat bugged out. It makes them look cut, but the result is pugs are always having problems with their eyes. At the most extreme, it’s not uncommon for the eyes to fall out due to some rather banal blunt trauma. The eyes can also prolapse if the dog pulls to hard on a lead, which is rather abnormal. Such bugged out eyes can have problems in simple maintenance. Often, they don’t produce enough tears to keep their eyes fully hydrated and clean, or they have eyelids or eyelashes that rub up against the eye so much that it causes ulcers.
It really isn’t that odd to see pugs missing eyes. It certainly adds to the character and to the mystique of owning a monkey-faced dog, but it isn’t something of which someone should be proud.
It’s rather horrifying.
So the pug’s “headpiece”– as the dog show people like to call it– is really quite defective.
But that’s not the only conformation problem they have. Breeding for the double curl in the tail is actually a selection for abnormally-shaped vertebrae. Breeders want the tail vertebrae to be strangely shaped so it will curly, but they can have the same thing happen to any of their vertebrae.
So it’s not unusual for them to have severely deviated spines.
Then they are the joint problems.
It’s not really a working breed, so people haven’t really paid that much attention to the problem.
Hip dysplasia is also a difficult condition to classify. There are clearly both genetic and environmental causes, and it is also difficult to trace it down to breeding for a particular conformation type.
But there are also a series of problems that pugs have solely because of their reduced genetic diversity. In the UK, an analysis by Imperial College, London, found that the effective population of pugs in that country is only 50 individuals. At the time, there were an estimated 10,000 pugs in the UK, which means they have a significant amount of inbreeding.
This inbreeding, which is actually the result of the closed registry system that runs riot in the world of purebred dogs, has exposed a tendency to develop necrotizing meningoencephalitis, which is now called “pug dog encephalitis.” Only a little over 1 percent of all pugs will develop the condition, and now there is a genetic test for it. It is associated with homozygosity within the DLA/MHC genes, which is what happens when inbreeding is done without trying to maintain DLA/MHC diversity. This condition is fatal, and there is no cure.
The weakened immune system that comes from such an inbred population also makes pugs more susceptible to demodectic mange. Most dogs have no problem with demodex. Demodex mites live on dogs and normally cause no problems. However, when a dog’s immune system is weakened, the mites can get out of control and cause mange.
So here we have a dog breed that is fairly common and growing in popularity that has severe issues with its unusual conformation and its compromised genetic diversity.
And no one really seems to care.
The pug, as it exists, is no longer under the selection pressures of natural selection.
Nor are most domestic dogs.
However, in this case, not only have the selection pressures from nature been relaxed, artificial selection has run amok.
We have succeeded in producing an animal so fragile that we cannot leave it out on a balmy spring afternoon. It is an animal so fragile that it is quite prone to having its eyes fall out of socket.
It is a perverse creation, but the perversion is simply not seen.
It is almost impossible to have a conversation about changing the pug without having a discussion about outcrosses, which of course leads to the attack on puggles. Puggles are designer dogs that are the result of breeding a beagle to a pug. They were heavily milled and mass-produced in the US a few years ago, and they developed a bad reputation.
But no one is talking about puggles. What is normally suggested is that one do a simple outcross to a less extreme breed, but of course, the pug fanciers won’t have anything to do with it.
Many are under the delusion that this breed has existed in its current form for thousands of years, which even a simple Google search for old pug photos and paintings will show you that it simply isn’t true.
Further, the breed in its current form was developed in the past 400 years in Europe, not in China. For a very long time, it wasn’t even known that it was a Chinese breed, and if black pugs had not been imported to England from northern China int he 1880′s, we would have never known about their origin. Though they became established in the seventeenth century in the Dutch Republic through trade with China, no one seemed to remember where they came from.
This breed could be fixed if we thought it through a bit, but that’s unlikely to happen.
There are no “working-type” pugs, and any dogs of this type still living in China are likely to be quite rare and quite different from the Western pug.
The entire existence of this breed is as a pet. Not that there is anything wrong with breeding a pet breed, but because it is a pet, it is possible to create fantasies about them.
It is possible to delude oneself about how healthy these dogs actually are.
It possible to delude oneself into believing that there is nothing wrong with breeding for such extremes.
Without any sort of working test or ancient landrace for which one can compare the Western pug, the breed can exist as the monkey dog. One etymology of the word pug is that pug was used to describe a type of New World monkey– probably a marmoset or tamarin–and there were “pug monkeys” and “pug dogs.”
And that goes to precisely the problem these dogs face. People have forgotten that this animal is still dog, and dogs have a particular anatomy and physiology. We can bend it and distort it through selective breeding, but at some point the bending becomes a perversion. It becomes burlesque.
It becomes unworthy of the relationship between man and dog.
It is something that shouldn’t be honored.
And it certainly shouldn’t be promoted as cute.
It is a problem that no one wants to talk to about.
We have let the pug down, but no one wants to say anything about it, lest one be deemed an animal rights activist.
We could fix these problems, but then we’d have to break the delusions and fantasies.
And unfortunately, too many would rather cleave onto those than admit the reality of the situation.
Maybe the pug is doomed.
Right now it surely is.