How to win The Health Test Game

By Carol Beuchat PhD

New technology has made it relatively easy to identify and test for single recessive mutations that cause genetic disorders in dogs. In fact, there are tests available now for well over 100 disease-causing mutations, and the list continues grows longer. DNA testing has become the badge of the responsible breeder, who only produces puppies from "health tested parents".

However, the notion that health testing the parents is the key to producing healthy puppies is incorrect. The reason is that we can only test for mutations we already know about. Every dog carries mutations that have probably been passed down for many generations and, as long as a dog inherits only a single copy of the mutation, it usually has no deleterious effects. In fact, every dog carries mutations you don't know about that can become a future health problem in the breed if a puppy inherits two copies.

Breeders are now caught in a potentially endless loop of The Health Test Game. It goes like this:

​Every dog in your breeding program has recessive mutations you don't know about. (See The fiction of "knowing your lines".) It simply isn't true that if you breed only healthy parents, you will produce only healthy offspring. That's like assuming that it's safe to cross a battlefield because you can't see any land mines. They are there, and if you tromp around long enough, you'll find them.

Over and over, we play the health test game and create new problems for ourselves. What can we do about this? How can we break this cycle?
​

​Really, it's this simple.

"Health testing" will not eliminate genetic disorders in dogs. (See Why DNA tests won't make dogs healthier.) We know how to fix this problem. We just need to do it.

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