A plethora of canine DNA health tests and genetic testing providers are on the market today, and it can be difficult for breeders to determine which tests are applicable and useful. Tests vary from one single test for a specific genetic variant related to a disease to multiplex panels that provide results for hundreds of genetic variants at once.

What are DNA Health Tests?

Canine DNA health tests can identify genetic variants associated with various health conditions or diseases that the dog may carry or be predisposed to. The mode of inheritance of these genetic variants determines their interpretation. However, it’s essential to understand that these tests indicate genetic predisposition, not the presence of the disease itself. Many of the DNA tests are named after the disease they are associated with.

For example, Progressive Retinal Atrophy (PRA) is a degenerative disease of the eye that leads to blindness. Currently, over 25 specific genetic variants have been identified in dogs that have been associated with the disease PRA. This progressive eye disease is diagnosed by a veterinarian, typically when a dog develops signs of blindness. Specific breeds have different PRA-associated variants within their populations, and breeders must take care to order the test that is specific to their breed. For example, two genetic variants are related to early-onset PRA. One variant, a deletion involving the PDE6B gene affects Spanish Water Dogs, and the second variant, an insertion involving the CCDC66 gene, affects Portuguese Water Dogs.

Confirming the gene involved is sometimes not sufficient for identifying the appropriate test. For example, multiple PRA-associated variants involve the PDE6B gene, including one variant that affects Sloughis and another variant found in Irish Setters. Each variant can have slightly different disease manifestations as well. Additionally, PRA can develop even in dogs that do not test positive for any known PRA-associated variants, as other genetic variants likely exist and have not yet been identified.

What DNA health tests are important for my breeding program?

Multiplexed technologies provide efficient, cost-effective methods to test hundreds of genetic variants at once. However, most of the variants tested for do not apply to a specific breed, or even mixed breed dogs. In a publication evaluating over a million dogs tested with a panel of 207 markers, the top 20% most prevalent disease-associated variants accounted for 98.3% of all disease-associated variants detected in all dogs.¹ In other words, only about 40 disease-associated variants were found across all breeds. Many of the other variants were initially identified in an individual dog or litter and are not widespread.

Instead of testing for everything available, breeders should focus on DNA health problems that occur within their breed. Parent clubs have come together to determine relevant problems in their breed, and their health statements are posted on akc.org (https://www.akc.org/breeder-programs/breed-health-testing-requirements/). Recommendations are based on historical knowledge and experience of expert breeders and are used for AKC® Breeder of Merit and AKC® Bred with Heart certifications. Many clubs choose to perform health surveys to determine how common diseases are in their breeds. Breeders may also find specific problems within their lines, so these parent club health statements may not include every test a breeder may want to screen for. Meticulous record keeping and receiving follow up from owners helps track health problems that occur within a specific line.

How do you pick a genetic testing provider?

Currently, there is no regulation of canine genetic testing providers, and the accuracy and reliability of DNA tests can vary. It is important to choose a reputable company with a track record of accurate results. Some indications of reliability include voluntary certifications, such as meeting ISO standards. Although not specifically for dogs, labs with CLIA (Clinical Laboratory Improvement Amendments) Certificate of Compliance are allowed to perform human genotyping, which shows commitment to achieving the highest quality standards. Labs that perform only animal testing cannot achieve CLIA certification.

The technology behind each DNA test for specific genetic variants is also not the same for every variant. Although the specifics are proprietary, genetic testing providers should provide information about whether a test is direct or indirect (linkage). In general, direct tests are looking for a specific change in DNA that is associated with disease and tend to be more accurate. Indirect tests, or linkage tests, look at a variant that is located close to the direct variant in the genome, and are more prone to error. Breeders are advised to read the fine print for every specific genetic variant that they are concerned about in their breed.

DNA results can also be uploaded to the Canine Health Information Center (CHIC), and OFA provides a list of acceptable genetic testing providers. This list is not exhaustive, and OFA cannot verify the accuracy of the results from these genetic testing providers.

AKC DNA + Health

In the next few months, AKC DNA is launching AKC DNA + Health, which includes more than 328 tests for health markers, as well as traits such as color, coat, etc. This test utilizes SNP chip technology to enable reliable, cost-effective results with an efficient turnaround time. Most importantly, results will be filtered by parent club recommended health statements, so breeders remain in control of highlighting the most important tests for their breed. Results for other tests will still be provided, as these tests may be relevant in certain lines or individuals.

To complement the health testing, the AKC Canine Genetic Counseling Center has also been created to provide practical information and advice on the interpretation of these test. Staffed by veterinary professionals, this service aims to provide information so that breeders can make the best decisions. In other words, we will not tell you what to breed; only breeders can make that decision. For questions about the upcoming health test, please email dnahealth@akc.org.

Dr. Claire Wiley is the Executive Director of the AKC DNA Program.