It can be tough for veterinarians to figure out what to do with these DNA results—especially when some test providers are scrupulous and others less so. “It’s a little bit of a perfect storm of a slightly Wild West behavior,” says Aimee Llewellyn-Zaidi. “Who are these genetic-test providers? There’s no standards. There’s no regulations. There’s no independent assessing body.” Llewellyn-Zaidi is project director for the Harmonization of Genetic Testing for Dogs, a genetic database that is attempting to bring some order to the world of dog DNA tests for health. “Veterinarians are rushing to catch up,” she says. “Consumers are just going ahead and using the tests.”
Several dog owners told me their vets were curious when they brought in a DNA report for their dogs. When I reached out to the American Veterinary Medical Association, American Animal Hospital Association, and several state veterinary associations though, most either did not respond or responded to say direct-to-consumer DNA tests weren’t on their radar. Meanwhile, the veterinarians and canine geneticists who did want to talk were largely skeptical.
“Veterinarians, we’re not really educated in clinical genetics because it’s a brand-new field,” says Lisa Moses, a veterinarian in Boston. Moses was especially concerned about the health risk information. Doctors can refer human patients to genetic counselors, she points out, but veterinarians don’t have dog genetic counselors on call. Moses co-authored a comment in Nature earlier this year, where she recounted the story of a 13-year-old dog who was losing her ability to walk. Her owners decided to buy a $65 direct-to-consumer test, which showed a mutation linked to a neural disease called degenerative myelopathy. Convinced she would slowly die of the disease, her owners put her to sleep.
But the mutation for degenerative myelopathy is notoriously hard to interpret. Kari Ekenstedt, a professor of anatomy and genetics at Purdue, calls it the “ever-controversial DM mutation.” The problem, she says, is that not having such a mutation is a good sign a dog does not have DM, but having a mutation does not guarantee the dog has the disease. It’s possible the dog Moses wrote about had an entirely treatable spinal disorder and did not need to be put down.
The episode prompted Moses to take a closer look at the pet DNA industry, and she came away even less certain of how to interpret the results. While the Food and Drug Administration regulates 23andMe, no one is looking at pet DNA tests. Moses says she had been taking the DNA tests at face value, and she began to wonder if she had caused her patients too much worry by doing so. “I didn’t understand how iffy, how little there was for me to really take stock of these tests,” she says. Carrie Waters, a veterinarian in Dallas, echoed the sentiment. “There’s a number of labs doing it, but I’m not totally convinced there’s the best quality.”
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