In our program, we prioritise personality and health. We take the health test results from our sires and dams seriously. This being said, while OFA testing (such as patellas and cardiac) are indisputable, the same cannot be said for a lot of genetic testing. Some DNA tests are more accurate and more well-developed than others. For our puppies’ genetic health, we use Embark and occasionally Gensol, which are both known to be some of the most accurate companies for genetic testing.
This being said, even Embark and Gensol can make mistakes with their genetic tests. Being a mail-in test, factors such as quality of the swab, other dogs exposed to the swab, and the environment and weather, can all play a role in the accuracy (or inaccuracy) of the final genetic results. Genetic testing can be a valuable tool, but at the end of the day, physical OFA’s are significantly more reliable and important in telling the health of a dog.
One of the genetic problems that Embark tests for is a condition known as Progressive Retinal Atrophy, or PRA. This is a condition which can affect the eyesight of a dog. Some types of PRA only occur late in life, while others can occur at 1-2 years old. This condition is known to be present in the dachshund breed, and so there are frequently breeders and pet owners alike searching for PRA Clear dachshunds. However, there are many problems with this.
The first problem is that breeding only PRA clear dachshunds will limit the genetic diversity of the breed. If we spayed and neutered ALL PRA affected and PRA carrier dachshunds tomorrow, then we would be left with only a very small percentage of dachshunds. Then, spaying and neutering the remaining PRA clear dachshunds which fail their OFA’s or are not clear for other genetic conditions, we would be left with an even smaller population. This would force breeders to turn to inbreeding, which can cause genetic issues much more dangerous than PRA, as well as eliminate healthy bloodlines.
Secondly, testing for PRA is relatively new and unreliable. There are dozens, if not hundreds of types and variations of PRA which cannot be tested for. Thus, a dog that tests as clear is still at risk for developing PRA. In addition, false positives and false negatives are not uncommon whenever testing for PRA. One of our beloved sires we purchased from another breeder. He was labelled as PRA clear since both of his parents tested as clear for PRA Cord4. However, our male tested as a carrier for PRA Cord4. The good news is that all types of PRA can be caught through getting a dog’s eyes OFA’d.
(https://www.petmd.com/dog/condition/progressive-retinal-atrophy-in-dogs#) (http://www.wienepedia.com/articles/pra-brief.php)
Lastly, a dog that tests as affected for PRA is not likely to ever actually develop the disease. Called, “Incomplete Penetrance”, a dog that has two copies of the PRA gene may never develop the disease at all.
(https://www.pawprintgenetics.com/products/tests/details/24/?breed=355)
For these reasons, our program focuses on OFA’s for our primary health testing and breeding decisions, while using Embark testing as a general guideline— but ultimately, we take all results of PRA in our dachshunds with a grain of salt, and do not let PRA results affect our breeding decisions in two dogs which are otherwise completely healthy and genetically clear. However, if we ever were to have a dog develop PRA or any other eye condition, we would take action and spay/neuter.