Breeding and breathing

A century and a half of dog breeding has left its mark...
13 September 2019

Interview with 

James Serpell, University of Pennsylvania


Vintage illustration of a dog coming out of a kennel


Where do dogs come from? By looking at their DNA, scientists can tell that they’re most closely related to wolves. They evolved thousands of years ago when humans domesticated them. And we bred them intensively, because we relied on them to protect our livestock and stop us from starving. Normally evolution on this scale takes millions of years - but here it had tens of thousands. And this was only a warm-up act. In the 19th Century, the real dog breeding began. Phil Sansom spoke to James Serpell, professor of animal ethics and welfare at the University of Pennsylvania...

James - In the 1850s, Victorians started to focus on dogs as a kind of a hobby breeding species, and you've got the creation of something called the ‘dog fancy’. Prior to the 1850s, there were lots of different breeds, or more correctly landraces of dogs out there; people took these local varieties and then genetically isolated them from the rest of the population and started breeding like-to-like. They created studbooks so that they knew exactly who had been bred to whom. That in itself creates problems because you've got such a limited pool of genes to draw upon in the first place, and you also get things like inbreeding depression occurring, and founder effects, and genetic drift, and so on.

Phil - Can you explain what you mean by this inbreeding depression, and founder effects, and all these things?

James - Well, founder effects is essentially just the result of starting with a very small initial population. So instead of having a wide diversity of genes contributing to your population, you're selecting from a very small number to begin with. Genetic drift is when just through random processes, a dog dying or a dog disappearing from the population... because you've got such a small initial founding population, that tends to make that genetic pool drift in peculiar directions. And inbreeding, the sort of things that happen then are… if you've got a deleterious gene in the population, usually that will be masked by more dominant genes that are healthy. But if you start doing a lot of inbreeding you can mess that up and what you get is the expression of these deleterious genes. And those deleterious genes could be something that reduces fertility, that increases predisposition to cancer, all kinds of possible things can go on. So yes it was bad news for the genetics of the animals. And people actually recognised the dangers very early on even before anybody knew anything about genetics.

Phil - Has that led to consequences for dogs today?

James - Yes! So for many breeds they are quite inbred. The other fact has been that they wrote down what they called the Breed Standard, which is a verbal description of the breed. And sometimes these Breed Standards are kind of absurd when you look at them in practical terms. So in the English bulldog, for example, the Standard says that the distance between the tip of the nose and the forehead, essentially, should be a short as possible. So obviously if you’re a bulldog breeder or a bulldog judge at a dog show, what you're looking for is an animal that has a very short distance between the nose and the forehead or no distance at all, and in fact that's sort of what has happened to the bulldog’s head. The nose has been pushed backwards until it is in fact flush with the front of the dog’s head, and as a result, most bulldogs have difficulty breathing and many will require surgery to correct this problem. Now I'm sure it was never in anybody’s design to produce an animal that can’t breathe. But if the Breed Standard said that there should be minimal distance between the tip of the nose and the forehead, then that’s what the breeders and the judges were aiming for. And they've succeeded horribly. And this is not just in reference to the dog's head, it's a problem now with the fact that many of these brachycephalic breeds, like the bulldog, the ones with the squashed faces, can't actually breed properly. The puppies have to be born by caesarean section. And this is also a product of breeding for a very large head size in relation to hip size. It's unsafe now for the female dogs to give birth naturally. Clearly when you get to that sort of point, something has gone horribly wrong with the process.

Phil - It seems like the flat-faced dogs are really good examples of the worst of this kind of thing. So why is it that the breeding standard has said that they should have such short faces, and that we’ve bred them like this?

James - The research that’s being done so far suggests that people find this look very very appealing. To some people these dogs look kind of infantile, look like human infants, and they find them irresistibly cute, irresistibly appealing. In the last ten years, a lot of these breeds have shown a massive increase in popularity across Europe and the United States, things like French bulldogs, pugs, English bulldogs, they became super popular breeds.

Phil - Are these dogs suffering?

James - Absolutely, without a doubt. And they may suffer for their entire life. The problem with these dogs is they can't breathe, you know, if you try and exercise them too much they will collapse. They have severe respiratory problems, they have all kinds of skin fold problems, their eyes bulge out and tend to get injured because you know, they’ll crash into a branch or an object on the ground and scratch the cornea of the eye. Many of these dogs will have to have surgery to correct the breathing problems. They’re going to develop other health problems during their lifetimes that’s going to cost the owners money and a lot of grief, they're probably going to die young. Normally if something we’re doing to animals is causing this level of suffering we would have laws and rules that would restrict that type of behaviour. But because these are pets and they live as members of our family, somehow we don't think of them in quite the same way. But I think a lot of it is just ignorance and public blindness to the problems that have been created, they don't really see it for what it is.

Phil - Can I ask, do you own a dog?

James - I do yes.

Phil - What kind of dog?

James - It’s a sort of average mutt-looking, shaggy haired, black dog, medium size, very nice temperament. We call him a Bosnian Snakehound. This is a joke, he did once meet a snake and he chased it into a hole. That is probably the most exciting thing he's ever encountered.


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