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When Mars Petcare launched its first DNA test for dogs, in 2007, you could only get it through a vet. The breed-mix test required a blood draw, and Mars thought vets could help interpret the results for inquiring dog owners. But veterinarians, it turned out, weren’t so keen on newfangled DNA tests then.

“We struggled with vets,” says Angela Hughes, the veterinary-genetics research manager at Mars’ Wisdom Health division. “There’s a lot of demand out there, but sometimes the vet is a little more a hindrance than a help.” So in 2009, after a technical change that allowed Mars to extract DNA from saliva instead of from blood, the company switched gears: It sold its Wisdom Panel test directly to customers.

Since then, the direct-to-dog-owner market has become bigger and more crowded: Embark, DNA My Dog, and Paw Print Genetics are just a few of the other companies eager to ship a cheek swab straight to your door. If the story sounds familiar, it’s because dog-DNA companies are following in the footsteps of 23andMe. The various dog tests offer breed mixes and, in some cases, risk estimates for more than 150 health conditions. And now, to bring it full circle, dog owners are going to vets with DNA reports in hand.

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,” Aimee Llewellyn-Zaidi says. “Who are these genetic-test providers? There’s no standards. There’s no regulations. There’s no independent assessing body.” Llewellyn-Zaidi is the project director for the Harmonization of Genetic Testing for Dogs, a genetic database 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 dog. When I reached out to the American Veterinary Medical Association, the 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 genetic counselors on call for dogs. Moses co-authored a comment in Nature earlier this year, in which she recounted the story of a 13-year-old dog that 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 (DM). Convinced that she would slowly die of the disease, her owners put her to sleep.

But the mutation for DM is notoriously hard to interpret. Kari Ekenstedt, a professor of anatomy and genetics at Purdue University, 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 said. 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,” she said.

For their part, the leading dog-DNA companies realize a total lack of regulation is bad for their industry’s reputation. “The industry could be tainted by a bad actor or two. We do feel like it’s important to try to self-regulate as best we can,” says Hughes, of Wisdom Health. It’s why Wisdom Health and several other testing companies are collaborators in the Harmonization of Genetic Testing for Dogs project.

At its core, the harmonization project is a database of dog genes that have been linked to different diseases in different breeds. This isn’t as simple as it sounds. Gene names aren’t always standardized; neither are breed names between countries. “We have to make sure we’re even talking about the same dogs,” Llewellyn-Zaidi says, which illustrates the challenge for vets delving into the genetics literature.

Getting breeds right is key because many markers linked to a dog disease are breed specific. (Some companies offer breed-specific DNA tests to account for this.) In many cases, those disease markers will never be found in another breed. But in a few rare cases, they can mean different things for different breeds. For example, says Ekenstedt, Factor VII deficiency is associated with mild bleeding in beagles, in which it was first discovered, but with severe bleeding in Alaskan Klee Kais.

A typical vet isn’t likely to be familiar with the details of hundreds of mutations. And in fact, Ekenstedt admitted that even she, a trained canine geneticist, isn’t. When I asked about a specific trait called alanine-aminotransferase activity, sometimes tested for in dog DNA, she said she wasn’t so familiar with it. “Even an expert like me can’t keep up,” she says. “No regular veterinarian has time to keep up with it. Ultimately, I think we need to have more specialists who are more visible for regular vets to reach out to.”

In some cases, the DNA-test companies have stepped in to fill that void. Hughes told me her team regularly fields questions from customers about their dog’s specific results. Embark also has a veterinary team that proactively reaches out to customers about their results. “We don’t want someone opening an email and being hit by something and not knowing how to interpret it,” says Adam Boyko, one of Embark’s founders.

One Embark customer, Emily Rose Cunningham, told me that the company reached out about her dog Dora, an American hairless terrier that had a marker linked to enlarged hearts in another breed. Cunningham took Dora to see a dog cardiologist. Her exam came back normal, and Cunningham reported the results back to Embark. Since then, at least one other American hairless terrier has been found with the marker. Cunningham told me she appreciated that Embark was collecting data for further research. “I like that there’s continued research rather than just getting test results and it’s done,” she said.

In convincing tens of thousands of dog owners to buy DNA tests, these companies have also amassed huge genetic data sets—data sets that will be valuable for future dog research. “There’s just not funding in the academic world for those kinds of studies,” says Boyko, who is also a professor at Cornell University’s veterinary school. Wisdom Health and Embark, for example, have both published papers about genetic variants in their customers’ dogs. As these data sets get bigger, they will power more genetic discoveries. In this way, though the direct-to-consumer dog-DNA market has grown quickly, it is still early days for canine genetics.

Today Mars sells 90 percent of DNA tests directly to consumers, but it does still sell some DNA tests through vets, under its Banfield and Royal Canin brands. Marianne Bailey, a vet in Maryland, said her clinic recently started offering one of Mars’ tests. She didn’t like the idea of dog owners bringing in a DNA test they had bought off the internet. “Then I don’t know anything about this test or how they run this test,” she says. But her clinic decided to offer a DNA test—one the staff has chosen and vetted themselves—because dog owners kept asking about DNA tests. The owners’ interest was piqued, of course, by all the direct-to-consumer dog-DNA tests now on the market. Everyone, including veterinarians, is figuring out what it means.

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