Saturday, July 24, 2010

Breeding healthy Dalmations

The problem

All dog breeds have problems that occur more in that breed than in any other. In the case of Dalmations, the problem is stones — the formation of crystals in their urine. Not every Dalmation gets stones. However, every Dalmation has a high level of uric acid in their urine, which predisposes them to stones. Their kidneys are missing an enzyme which converts uric acid to another substance (allantoin). When the uric acid sits around like that, stones can form.

Just having a urinary bladder full of stones is not always a big deal. However, when the stones get big enough, they can block the outflow of urine. (This happens more often in boy dogs — smaller outflow tube!) This blockage is a veterinary emergency, and may require surgery to correct. Once a blockage is corrected, there is no guarantee that the dog will not form stones again later in its life.

If all Dalmations have unusually high levels of uric acid, why do only some of them develop stones? We aren’t completely sure. It is likely that the levels of uric acid might play a role (more uric acid, more stones). Diet and other environmental factors may also play a role.

Why the obvious solution doesn’t work

So just breed the trait out, right? Find Dalmations with normal uric acid levels, and only breed those dogs.

It turns out that there are no Dalmations with normal uric acid levels. The gene which causes Dalmations to not be able to convert uric acid is located very close to the gene for those distinctive black spots, and was probably bred in when the spots were. You can’t find a normal Dalmation to use to try to breed out this undesirable trait.

You can’t even breed Dalmations with slightly lower uric acid levels, to try to gradually reduce uric acid levels to a normal level. Their levels are all completely out of the normal range. You would only be able to breed them down to a low abnormal, not into normal range.

In short, there is no way to introduce the “good” version of the gene into the Dalmation breed without doing some gene splicing — or breeding Dalmations to dogs of a different breed.

An alternative solution

A medical geneticist, Dr. Robert Schaible, bred a single Pointer to a Dalmation. He then bred one of their offspring to a Dalmation. He continued breeding back offspring from later generations to Dalmations, selecting for both low uric acid levels and for the things you usually want to see in Dalmations (their particular temperament and coat markings). This project, the Backcross Project, eventually resulted in dogs that are just like purebred Dalmations in all other ways, but have normal uric acid levels — “normal uric acid Dalmations.”

So the problem is solved, right?

Unfortunately, the American Kennel Club (AKC) will not allow the normal uric acid Dalmations to be registered, contending that they are not purebreds. What are the consequences of this decision?
  • Normal uric acid Dalmations cannot be shown in AKC conformation classes. This means that breeders who compete in these classes (based on how a dog looks) will not be willing to breed their dogs to normal uric acid Dalmations. The AKC is hands-down the biggest game in town when it comes to conformation shows. Therefore, the pressure is intense to continue to breed high uric acid (purebred) Dalmations, and in fact that is what is happening today.
  • People who want to own Dalmations just as pets are unlikely to be aware of the existence of normal uric acid Dalmations, or may not have access to one of the very few low normal acid Dalmation breeders. Even though they may never intend to show their dog, or even register it, they will still be more likely to buy a Dalmation with this genetic problem.
What is a purebred, anyway?

Breed registries are relatively recent — within the last hundred years or so. Before then, if it looked like a Dalmation, and so did its parents, it was a Dalmation. At some point, however, breed stud books began to be kept, and they were “closed,” meaning that a dog could only be considered purebred if both its parents had been registered. This prevents breeders from bringing in fresh genes from outside the breed. The selection of those founding dogs that were chosen to be the original Dalmations was necessarily arbitrary. Why shouldn’t new ones be allowed in now?

What you can do

Unfortunately, there is not much that the average dog owner can do about this particular problem; it is in the hands of the AKC and of Dalmation breeders. If you are in the market to buy a Dalmation puppy, you should definitely learn about normal uric acid Dalmations.

On a larger scale, it is important to be aware of what the AKC is and what a “registered” dog is. When people say a dog is “registered,” they usually mean that it has been registered with the AKC. (Other kennel clubs do exist, such as the United Kennel Club, or UKC, which does allow registration of low uric acid Dalmations.) However, AKC registration does not guarantee that the dog is healthy, or even that its breeder put any effort into breeding healthy parents. It means that both parents were registered with the AKC, and absolutely nothing more.

If you are going to buy a puppy, talk to the breeder about what genetic problems the puppy might have, and be sure that the breeder really cares about eliminating those problems from the breed. Don’t settle for the explanation that “all dogs of this breed are likely to have this problem; that’s just the way it is.” Is there a solution that the breeder isn’t taking, because it would cause some change to the breed? If so, think about whether you agree with that choice. In some cases, you may find the choice to be a good one. If not, you may want to reconsider buying a puppy of that breed.

4 comments:

  1. Actually, it the Dalmatian Club of America that refuses to let the LUA Dals be registered with AKC. They've voted a couple times not to allow registration. In the last argument, er, discussion I had with a Dal person, I asked at what point she would consider the LUA Dals to 'pure' again. She told me, "Never." That is the mindset of some people in the 'fancy', breed purity is like a religion. Even more twisted are the people who think that having a high risk of certain diseases is simply 'part of that breed.'

    I have two breeds, Salukis and Azawakh, that not only have aboriginal populations in their home range (the Middle East, Africa), but actually have a mechanism whereby such animals can be registered. And there are still people who don't consider the country of origin dogs to be 'pure' because they don't come with multigenerational pedigrees. As I said, religion.

    I am enjoying your blog :)

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  2. Good point! I did oversimplify the point about the AKC vs the Dalmation Club of America a little bit, to avoid getting into an explanation about the breed clubs which make up the AKC. I didn’t want the post to get too long.

    Your discussion with a Dal person is really interesting. I wonder what it would take to try to change the mind of someone who has that perspective.

    Glad you are liking the blog!

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  3. A bit of devil's advocate coming from a raised-by-a-purebred-breeder (and hopefully not a pest) person...
    The solution might be in market economics (demand and supply) and places like shelters.
    Thousands of dogs, all ages, sizes, with spots even, exist in this country for not only a fraction of the cost but with hybrid vigor (like the lua dals, maybe even more) and good temperaments.
    Maybe a focus to take is recognizing the inherent fallacy of organizations like breed and kennel clubs and instead educate about temperament testing and safe, effective, positive behavioral modification techniques.
    Two cents in.
    :-)

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  4. Good approaches, and I don't think it's devil's advocacy at all -- I completely agree with you. Maybe I should have specifically suggested shelter dog adoption here. I guess I was speaking to people who were set on getting a dal, but it's an excellent point.

    ReplyDelete