Dog Breeding in the Digital Age, Part One: A Flood of Biblical Proportions

This is the first in a series of articles dealing with the challenges that modern dog breeders (and puppy buyers) face in the digital age. From new DNA tests, to the scores of websites tabulating data and factoids (more about this in a later article), to social media, dog breeders and buyers are bombarded with information.

While I believe in the free exchange of information (after all, that is why ChessieInfo was created), when that information is decentralized, disorganized, incomplete, incorrect, not explained well, or not put into context, it is as good as useless. People need to be able to make sense of the information they see every day.

Most dog breeders are not scientific researchers. Most researchers are not dog breeders. The future of purebred dogs lies in the gap, which is very wide. Add to this the fact that most breeders are extremely small-scale (one, maybe two bitches), and that gossip is the lingua franca of dog sports, and you have a recipe for disaster. Let’s look at the historical perspective, which gave rise to the analysis paralysis that dog breeders are currently experiencing.

In the late 1960s, something new was developed. It was a way for those breeding functional working dogs to detect and attempt to reduce the incidence of a crippling disease known as hip dyaplasia. It was a simple paradigm, and most everyone was willing to climb aboard. Just x-ray your breeding stock, spay/neuter those that didn’t have good x-rays, and breed the rest. Simple. Parent Clubs published articles about how hip dysplasia could be reduced. Advertising in some breeds was restricted to only those with a hip clearance number. In some countries, only dogs with a certain hip grade or higher were even allowed to produce registerable litters. A culture of peer pressure was developed, and because there was only the one “genetic” (really, only phenotype) test, it was simple to adhere to, and almost everyone climbed on board.

Then a few years later, another certification was added: eye exams. Now we could x-ray hips, *and* certify that our dogs were free of eye diseases like PRA and cataracts. The “test and eradicate” culture that already existed regarding hips shifted to this new test: now dogs had to have a hip number and an eye number. But still, with only two tests, it was pretty simple to adhere to. This continued for more than two decades, and became the norm. Keep in mind, most people stay in the dog game for five years or so, so by the time the third test (for elbows) came along in the early 1990s, these certifications were “the way it’s always been” from the perspective of most breeders.

The first DNA-based (truly genetic) test was released commercially in 1999. Since then, the number of tests available for breeders has blossomed…erupted…into a flood of tests. Some breeds have relatively few. Some have many. Some tests are gene tests, while others are phenotype tests. Some test for single-gene traits, while others look for one gene of a polygenic disease. In Chesapeake Bay Retrievers alone, there are tests for hips, elbows, eyes, patellas, shoulder OCD, thyroid hormone levels, cardiac abnormalities, and  von Willebrand’s disease. All of these are phenotype tests. Then we have the true genetic tests: prcd-PRA, Degenerative Myelopathy, Exercise Induced Collapse, Mucopolysaccharidosis-Type VI (a storage disease) and ED/SF, a rare skin disorder. A test for dwarfism is being developed, and one for epilepsy may have use in Chessies. New PRA tests have also been developed, and it may well be the case that a second or even third type of PRA, while rare, exists in the breed.

The things we test for, how we are testing (looking at DNA, not just at the results of the DNA), and how much we are testing, have all changed. What has not changed is the culture. There still exists the mentality that a dog must “pass” before it can be bred. Or if (heaven forbid) a dog that is a “carrier” is bred, it must only be bred to a tested “clear”. This mindset, and the peer pressure/rumor mills that accompany it (magnified by the use of social media) can be extremely destructive to the production of high-quality, overall healthy animals. Does this sound contradictory to you? After all, breeding to tested clears should reduce the number of carriers, right? Isn’t that the point? “And Lisa,” I hear you say “even the researchers say on their websites that carriers should only be bred to clears.” Let’s look at the bigger picture again.

Why do we have all these genetic tests all of a sudden? It seems like new ones come out almost every day. Where is this all coming from? And more importantly, where is it all headed? The completion of the genome for humans, dogs, and mice has led to an amazing discovery: dogs have many of the same genetic diseases as humans, caused by the same genes. This means that researchers studying say, bone cancer, can use dogs in their research. Dogs have a short breeding cycle, mature quickly, and are easy to get DNA samples from. They are also easy to work with, and (lo and behold!) have breeders who will line up to donate samples to any research project. The research team does not even need to bear the costs of housing, feeding, and caring for experimental animals. This makes for a mutually beneficial situation, where human research needs generate funds that dog breeders, even large Parent Clubs, would not normally be able to afford. In the mean time, there is a large population of test subjects available to research teams. In this climate, as genes are identified in dogs, and cross-mapped so that human genetics can be better understood, new gene tests which can benefit our dogs are also developed. The number of DNA-based tests will skyrocket. It will never get smaller.

As each new test is developed, the decision process for breeders becomes more complex. Remember what I said earlier about researchers not being dog breeders? They are looking at their tiny slice of the pie. Of course, if *their* particular test was the only test in existence, *and* it is a low gene-frequency type of trait, breeding carrier or affected/at-risk to clear is a no-brainer. However, with a number of tests now being done on each dog, it becomes harder and harder to find a dog that tests clear for everything that our bitch does not, *and* also (incidentally, um, tell me again why we breed dogs?) actually complements her! All dogs are carriers for many diseases. The more tests that are developed, the harder it becomes to weave our way around the genetic obstacles. In Chessies, we have already reached the tipping point.

It is difficult to breed dogs when one is limited to only one or two breedable bitches. Sometimes, one has to make a tough decision to do a breeding, even though that breeding may be carrier x carrier. It is very hard to breed good dogs without making some concessions along the way. By breeding only to tested clear dogs, you are automatically limiting your selection of potential stud dogs to that smaller group. If your bitch is a carrier for two different things, the selection is even smaller. And what if your choices are dogs that simply will not help your breeding program? What if you breed your carrier bitch to a stud who is not the best choice for her, and the pups turn out to be lesser quality than your bitch AND all carriers anyway (this has happened already…more than once)? Are we breeding fir quality dogs, or are we breeding for test results? The decision lies with each of us, and we should not be overly critical of those who make different choices than we might. After all, genetic diversity is maintained by individual breeders making selection choices that vary from what other individuals select on. If everyone breeds dogs along the same “recipe”, genetic diversity becomes irreparably lost, and quality suffers.

 

 

 

 

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About ChessieInfo

The ChessieInfo site was founded in 2008, as a means of sharing information on genetics and health of the Chesapeake Bay Retriever. ChessieInfo believes that it is only by understanding the uses...and limitations...of genetic principles, that breeders will continue to produce healthy, yet high-quality animals.
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