The claims that dog DNA-testing companies make can seem all but definitive: One quick cheek swab can tell you not only about the breeds that make up your pooch but also offer it a lifetime of health. Pay $65, and you can make smarter, science-based decisions about veterinary care.
But three canine genetics experts question those claims, saying consumer-marketed canine genetics testing is an “untamed wilderness” of weak science, unvalidated outcomes and conflicts of interest.
In a paper published in the journal Nature, the authors argue that DNA tests shouldn’t be used to make decisions about euthanasia or veterinary treatments.
“We don’t understand why nobody is talking about it,” said co-author Dr. Lisa Moses, a veterinarian and research scholar at Harvard Medical School. “We’re really worried that there’s this large-scale misinformation about what the tests’ power really is and how they’re being used for life-and death questions.”
Elinor Karlsson, a co-author of the Nature paper and director of vertebrate genomics at the Broad Institute of Harvard and the Massachusetts Institute of Technology, said the core problem is how consumer test results are being interpreted. Simply having a genetic mutation, she says, doesn’t mean disease will follow or that veterinary intervention is required.
“Finding something and then using it clinically are two different things,” Karlsson said. “If you take 1,000 dogs and look at them, the ones that carry that mutation, what are the chances that they’re going to get sick? What does the information mean about whether your dog is going to get the disease? That’s the piece we’re missing right now.”
What is possible, experts say, is to identify some genetic mutations in certain breeds and make sure those dogs are not bred with others with the same mutations, thus reducing the chance of inherited disease in puppies. For dog breeders, they say, that type of genetic testing is key.
But for consumers looking at reports about mutations in, say, a mutt, making sense of results is a murkier affair.
“Some of these companies are doing that counseling, but others just want to sell these tests,” said Jerold Bell, a board member of the Orthopedic Foundation for Animals. “It’s an industry that’s in its infancy, and the commercialization has preceded the educational process.”
Angela Hughes, veterinary genetics research manager with canine genetic testing company Mars Wisdom Panel, agrees that finding a genetic mutation is different from knowing what, if anything, to do about it. She added that her company makes that distinction clear for consumers.
“This panel has a lot of benefits, but it has to be used with caution,” Hughes says. “We may know of a mutation in Dobermans, and then we see it in dachshunds, then we have to do clinical validation studies to follow up and investigate that. What does the mutation actually do in dachshunds? So, we flag it for the dachshund owners and very clearly state what is a known problem in a breed and what is a potential concern that we are investigating with additional studies.”
Officials at Embark, another animal DNA company, also said it does proactive genetics counseling for customers and also offers it to breeders and veterinarians.
“As you get more genetic information, there are more opportunities to misinterpret it,” said Adam Boyko, a canine geneticist at Cornell University who is Embark’s chief science officer. “Dog breeders, when they started testing and there were one and two mutations, that wasn’t so bad. But when you’re testing for 50 or 60 mutations, you have to understand that it’s not always deleterious.”
Even so, he said, DNA tests like Embark’s can assist consumers in making veterinary decisions.
“It’s going to exclude certain diagnoses — never 100 percent, there can always be a new mutation that causes a disease — but it can definitely reduce the need for extra veterinary tests,” he says.
But Moses, the co-author of the Nature paper, said consumers should think of the tests as interesting and fun, but not use them to make veterinary decisions. “As consumers, you’re not getting much for your money here.”