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Genetic Testing Can Offer Breeders Clarity

George Sofrondis holding two dogs.

Genetic Testing Can Offer Breeders Clarity

It was back in 1998 when I first started attending dog shows and talking to exhibitors about genetic testing. There were conversations about how some tested for von Willebrand’s and how very progressive breeds, such as the Labrador Retriever, would collect blood samples and be part of what we called “20/20 Clinics”—collect and batch twenty samples in one day and everyone gets a 20 percent discount! Ah, those were the days when everyone worked together to get a discount.

What has changed for me the most over these 20 years is that I have built some great relationships and friendships with breeders, so much so that they gave me the nickname Genetic George. Because of these great relationships and conversations, I started the “Genetic George Explains It All” Facebook page. I do not in any way confess to being an expert, but I do think I have a really nice way of giving breeders an answer that reflects my understanding of the challenges all breeders face from having to breed responsibly, but more importantly, making sure they breed for sound temperament, not just health. I have a wonderful way of putting it all together and keeping the math simple.

Throughout my career, I have been asked many questions by breeders about genetic testing. In this article, I hope to address some of the more common questions and provide some clarity on the issues that breeders face.

George pictured with Charlie The Boston (His CFO) and Mary the Griffon (His CMO)

How do I breed responsibly when a genetic test is not available?

I get a number of inquiries about cherry eye and cleft palate, and to date, there is no genetic test for these conditions. Is it hereditary? Is it genetic? In such cases, I like to apply the “first-time mating” rule. If the cleft palate you see is part of a first-time mating (sire and dam) and you notice several offspring in this litter with the defect, then my rule of genetic thumb tells me that this is most likely hereditary. Remember, we cannot currently determine the genetics and mode (no genetic test), but we can say that based on the pedigree and mating, it is hereditary. Genetic George would advise to avoid this mating, and if you do use the sire and dam, then you should breed to another dam or sire that is unrelated by pedigree.

How can my dog have a disease that is not listed on the OFA site?

Another great question that often needs clarification. A genetic test is almost always published as having an association with a breed, i.e., it has been scientifically validated for a specific breed. This tends to create some confusion, as a disease may be seen across a great deal of breeds but the genetic test is not relevant to most of those breeds. A perfect example is cataracts. The genetic test is only of relevance to the French Bulldog, Staffordshire Bull Terrier, Boston Terrier, Australian Shepherd, and any mixes or varieties of these types. But here is where the confusion comes in, a breed of dog other than those listed above, can be affected by cataracts but will test negative for the disease because the test is not genetically relevant.

What happens if I get a dog tested and it comes back as positive or a carrier for a disease that wasn’t previously available for testing?

Over the last 20 years, the technology and genetic offerings have changed dramatically! The number of genetic tests has grown exponentially from the first and only genetic test available in 1989*, which was for Hemophilia in the Cairn Terrier, to approximately 130 genetic diseases in 2003, to now over 344 genetic diseases (as listed on the OMIA site as of March 2024).

Unfortunately what you have bred cannot be changed or corrected, the pups have gone. It’s about what you can and need to do for the next litter. Just be sure to take the initiative to research the disease before breeding, as they can be complex, i.e., dominant or recessive mode. Dominant (inherit one copy of the gene from a parent) means that the offspring will have a 50 percent chance of being affected by the disease. Recessive requires two copies of the gene (inherit one copy of the gene from each parent) to present.

What lies ahead?

Looking ahead, the genetic testing landscape continues to shift, with technological advancements leading to more comprehensive testing panels. However, the industry is also consolidating, with fewer laboratories operating. This change prompts discussions about the efficacy and necessity of expansive testing panels versus targeted, breed-specific tests. The huge commercial interest in phenotypic tests, from colors to furnishings, has been a real revelation in my time. When I first started, no one would pay $60 for any test to see whether their dog was EE or Ee. Today, it remains the first question they want to know. As Genetic George, I’m eager to engage with breeders regarding their experiences and perspectives about genetic testing. What do you feel is a pain point you have with genetic testing? What advancements or resources would you find helpful? What would you like to see in the future? Your insights on breed-specific data, disease prevalence, and the growing interest in phenotypic tests, from coat colors to physical traits, are invaluable.

Looking ahead, the genetic testing landscape continues to shift, with technological advancements leading to more comprehensive testing panels. However, the industry is also consolidating, with fewer laboratories operating.

I am enthusiastic and keen to hear what you, the breeders, think. As we navigate this genetic journey, your feedback is crucial. Whether you’re a member of the “Uber generation,” with modern priorities, or someone who, like me, still prefers hailing a cab, I’m here to listen and learn. Let’s discuss how genetic testing can continue to benefit our beloved breeds. Please share your thoughts and feedback with me at: [email protected].

Together, let’s shape a future where every purebred dog not only looks the part but lives a long, healthy, and happy life, true to its breed and beyond.

 

* Single base pair substitution of Factor IX (clotting) gene causing Hemophilia B in the Cairn Terrier. Disease: Hemophilia B – Coagulation Factor IX Deficiency – Mutation: c.1253G>A