At Snowfire doodles, health testing is our top priority. CDDY and CDPA are two genes that are just recently being tested in the doodle world. There has been a lot of confusion as to what exactly these genes mean, and whether or not they are even significant to doodles. What follows is the summarized conclusion of my extensive research into CDDY/CDPA. I'm not a geneticist and I’m not a veterinarian. I am, however, a passionate breeder with 15 years of experience, who loves researching and learning more about genetics to ensure that my puppies are the absolute best I can produce.
CDDY stands for chondrodystrophy, it’s the gene that, in some breeds, can mean an increase in cases of IVDD, which is a spine disease that affects breeds like Corgis and Dachshunds, and other “low rider” breeds. In my opinion, and in looking at my dogs and other breeders’ dogs, CDDY by itself shows very little physical manifestation in structure, if any. Sometimes it can produce a slightly longer torso, but not always. (Embark refers to CDDY as IVDD type 1, and states this gene is “extremely common” in many small breeds, and "may not be the strongest predictor of IVDD risk compared to other genetic or environmental factors.”)
CDPA is the gene for chondrodysplaysia, the short leg gene. CDPA is much more obvious; it is the dominant short leg gene and manifests as short little tater tot legs. (They are adorable as puppies, but they often grow up to look disproportionate, which is why we have retired all dogs in our program that carry CDPA.) They only need to carry one copy of CDPA to have short legs themselves and to pass the gene on to their offspring.
As a side note, I have been frustrated with Embark’s lack of testing for CDPA, as this is causing confusion for breeders who might think that CDDY is the short leg gene. It’s not. Animal Genetics and Paw Print Genetics test both CDDY and CDPA, so I recommend those companies. It’s important to know the results for both genes, CDPA in particular.
When a dog carries both CDDY and CDPA, they are considered a low rider breed. They will have a very long torso and very short limbs, (Corgi, Dachshund, Basset Hound, etc.) These are the breeds that carry both genes and are at a higher risk for IVDD. Statistics show that approximately 90% of toy poodles carry 1 or 2 copies of CDDY, but the occurrence of IVDD is extremely rare. The same is true of Beagles and Cocker Spaniels; almost all of them carry 1-2 copies, but there are hardly any cases of IVDD in those breeds. The Goldendoodle Association of North America (GANA) has the same thoughts that I do, and they are extremely strict with their standards and health-testing practices. They agree that CDDY has not shown to affect Goldendoodles at this point, but are recommending that breeders test their dogs for research purposes.
Paw Print Genetics has a great article on these genes, and they state that eliminating them would have unwanted consequences for some breeds that are meant to have these structures. For doodles, I believe that we should use this information and not pair dogs that carry both CDPA and CDDY or even just CDPA.
There are many genetic conditions that only affect certain breeds, for example certain types of glaucoma only affect border collies, and even if another breed has two copies of this gene, they are not at risk; the result is not significant and doesn’t matter for other breeds. I strongly believe that this is the case with CDDY/IVDD and poodles and doodles. IVDD is just not a common health issue in any poodle or doodle variant that we know of, which strengthens my belief that any testing of CDDY will be null and void for these breeds in the future.
To clarify, my conclusion is that doodles and poodles are simply not affected in the same way as “low rider” dog breeds are, as long as we are not breeding CDDY and CDPA together. For my own breeding program, I will not breed any dog that carries CDPA, but CDDY is not a concern. I respect other breeders’ opinions and their ability to do their own research and make their own choices for their programs. As breeders, we do our best to pair dogs that complement each other. Snowfire Doodles has been and will continue to genetically test our dogs and pair them in the best way to not only creates healthy dogs, but also dogs that are beautiful, friendly, well rounded family companions.