I tested my dog Iris using the Wisdom 4.0 DNA test, which is marketed to people who are curious about what breeds make up their dog’s heritage. I was not surprised to find out that she was 100% Bull Terrier, and I was pleased that she wasn’t carrying genes for either of the two genetic diseases included in the test, but this was also no surprise as neither is a known issue in her breed. The only breed-specific disease in Bull Terriers with a DNA test is Lethal Acrodermatitis, which has a single-gene test available through PennGen at the University of Pennsylvania. Using the Wisdom Panel piqued my interest in the in-home tests and the reasons they are growing in popularity.
I tested Iris at the request of Dayna Dreger, who is a canine research scientist at Purdue University. I met Dayna early in 2018 at a dog show in Indianapolis where she was collecting DNA for a project involving canine feet. She’s currently working on a dog color genetics project. Iris is black brindle but is starting to get more and more brown mixed in areas that used to be pure black, and Dayna noticed a photo of her on Facebook and wanted to include her DNA in her project. Check out a report on Dayna’s work identifying the relationships between dog breeds around the world, including some cool visualizations.
Popularity of In-Home DNA Testing is on the Rise
People are buying more DNA tests for their dogs, once again following a human trend to find ancestry and relatives through in-home DNA tests as shown in these charts based on Google Trends search data. Both types of tests see searches spike in November, suggesting they are being purchased as gifts. (NOTE: The spike in general DNA test search in April 2018 may be related to DNA Day on 4/25/18 – the canine DNA test companies seem to have missed this marketing opportunity!)
Health Reasons to Test Canine DNA
Dog breeders should do relevant DNA testing, for heritable diseases to avoid matings that could produce affected puppies. Purebred dog owners can find out if theirs dogs are at risk for an adult-onset disease. Many of the breed-specific tests are offered individually through universities, like the LAD test for Bull Terriers and Miniature Bull Terriers, but some also come bundled in DNA panel tests like the more expensive Wisdom Panel Health Test. The number of tests and laboratories offering these tests is exploding, and canine health advocates are trying to help people find and select tests by creating a harmonized database of available tests. Dog owners should careful when interpreting DNA-linked disease gene findings in breeds or mixes which are not the same breeds studied to initially identify the disease-linked genes. Similar diseases in different breeds can have different genetic profiles, and misinterpreting a DNA report can have disastrous consequences for individual dogs.
Testing to Determine Parentage
Purebred dog owners can also test DNA to determine parentage. The American Kennel Club requires that sires whose semen is collected and shipped for fresh chilled or frozen breedings be DNA tested so if there is any question, parentage can be confirmed. DNA profiles also come in to play for litters with multiple sires or in cases where purebred puppies’ parentage is disputed or unknown. Yes, there are scenarios in the purebred dog world that would be right at home on Jerry Springer! The AKC tests are used to determine parentage, or specifically to rule parents in or out, not to identify the breed of the dog in question. The AKC tests are most akin to DNA tests conducted on crime scene artifacts and for paternity tests to identify parentage with confidence. AKC does some direct marketing of these tests to new AKC titlists who can receive a colorful certificate displaying their dog’s DNA profile.
Should You DNA Test Your Dog?
People who are curious about the breeds in your dog’s family tree have a number of commercial DNA test options, but results will not necessarily be identical across all the DNA tests out there. The number and breeds of dogs used to establish the profiles are not identical across all the tests, so results should be considered directional rather than definitive. The Wisdom Panel has a fun quiz that illustrates how difficult it can be to guess which breeds are behind a given dog based on appearance.
DNA testing for dogs can be used to improve dog health, inform breeding decisions, identify parentage or likely breed makeup for a specific dog. Caution needs to be used using DNA to learn about dogs’ genetic risks; within a breed, consulting with your breed parent club can help you understand which tests are relevant and how to interpret results. If you have a mixed breed dog, more caution is needed before interpreting disease gene data, as what is known within a single breed may not apply to other breeds or combinations of breeds.