There are no "healthy breeds" and no thouroughly and eternally healthy dogs. Every living creature carries faults that sooner or later take us away. If we are unlucky, we are born with them and quickly disappear into the dark. If we are very unlucky, we toil our way through shortened, painful lives. If we are lucky, however, the mishaps are no worse than what we can live active and reasonably happy with for a long time. So it goes with humans; so it goes with dogs. That's what it costs to be a project thrown together by some twenty thousand different genes trying to cooperate: sometimes it goes wrong and sooner or later it ends.
It is the cost of being alive.
For purebred dogs, unfortunately, there is an extra cost. When we choose to breed for a trait - because that's what purebred breeding is all about: choose a trait and breed for it - it will bring with it that a certain type of error becomes more common than in a self-breeding dog population and more common in a certain defined group ("breed") than in another. It wasn't what was intended, but that's how it must go. Why?
All dogs and all humans carry a number of defective genes. As long as the faulty ones are not exactly the same genes in one individual as in all others, they will have limited impact. They are not noticeable. Or they are rarely noticed, and late. But the longer you breed on a small number of individuals, the more related to each other they must become - related precisely means carriers of the same genes. When everyone is sufficiently related to each other, the so-called breed-related or breed- typical diseases occur. They are neither breed- typical nor breed related . They exist, in reality or as a risk, in all kinds of dogs. But when you chose to breed pure one genetic peculiarity - color or shape or (in the olden days) the desire to hunt, or herd, or the guarding instinct - then you got disease genes slipping into the bargain. And then those genes were condensed by inbreeding. And then the stud book was closed, making the influx of non-mutated genes impossible.
So it follows that in every purebred breed there is a higher level of one or more genetic diseases than in a population of street dogs. That is the logic of the closed pedigree. Whatever disease it is, PRA or heart valve degeneration or kidney disease or something more manageable like CEA in Collies, it is, however, random: it depends on which genes happened to be in the small group that was the beginning of the breed. If you want trait breeding in a closed stud book, this is the bill you have to pay – or, rather, let the dogs take.
As long as the benefit of the trait selected for is clearly greater than the possible suffering inflicted on the dogs, it is acceptable. But when the characteristic selected for becomes an end in itself and the dogs' suffering is great, that purebred breeding becomes indefensible.
It is my opinion that parts of today's appearance-oriented purebred breeding is precisely indefensible - because those who do it can´t, or won`t, balance their gain (what they strive for and get awards for and make money from) against the cost (increased disease risk, bodies that are difficult to live in), which they let the dogs and dog owners take.
If you don't understand what I mean - look at Cavalier King Charles! Way back, people selected for the round skull and the big eyes and gave the dogs syringomyelia, the result of a compression of the cerebellum. It´s not what they meant to do, to be sure, but it is what they did.
Syringomyelia is found in other dog breeds, it is found in humans, but not often, fortunately - because it is painful. One vet said of the cavs: "Squeezing that brain into that skull is like squeezing a size 39 foot into a size 36 shoe." In order to get what was wanted, the appearance, relatives were bred. Closely, obviously, because in the 2016 study, CKCS averages a higher COI than a father/daughter pairing. But of course, they got that round skull shape. That was what was aimed at; that's what they got. You already know what slipped into the bargain? An inherited heart valve disease. It is found in many other breeds as well, but it is much more common and occurs earlier in cavaliers than in others.
It is the most common heart disease of adult dogs and is about twenty times more prevalent in the Cavalier King Charles spaniel than other breeds. Most show some signs of the disease by 10 years of age. It has a serious impact on welfare, causing respiratory and other difficulties, with severe discomfort due to breathlessness and coughing. Unless animals are euthanized, the disease causes death by chronic heart failure. (UFAW. https://www.ufaw.org.uk/dogs/cavalier-king- charles-spaniel-mitral-valve-disease. My emphasis.)
The valve disease has nothing to do with the shape of the skull, and of course it wasn't something anyone wanted, but the condition happened to be present in the individuals that were bred from and now it's everywhere. Something that occurs in one individual here and another individual there, among both street dogs and other "pure" dog breeds, is made very much more common in a certain "pure" breed through a small founder group followed by repeated inbreeding. In the next breed, the pattern is the same: it's just the disease that happens to be a different one.
Dying slowly because a heart valve is starting to look like wet paper towels is not the way to end life you would choose for yourselves, Cavalier breeders. You probably don't want syringomyelia either. So why do you keep going? Is your gain really worth so much more than the dog's loss?
Or is it so difficult to understand the consequences of the basic principle of purebred breeding?
Then we will take it briefly. This is what it looks like.
Inbreeding on a closed pedigree is a brilliant idea when you want to select and stabilize a trait, but it will end in disaster if you keep on going. There comes a time to quit.
Bodil Carlsson
*For an excellent explanation of what syringomyelia is, please read what a member of SvenskaPrazsky
Krysaryk Klubben writes after a single case is discovered in that breed http://spkk.se/syringomyeli-i-rasen/
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