Should you get your pet’s DNA tested? Scientists urge caution
You’ve probably seen an ad for a company that wants to tell you about your genome. Just spit in a tube, send it in, and you can learn about your disease risk.
Now, you can do the same for your pets, at least according to nearly a dozen—and growing—companies on the market. But how accurate are these tests—and why are these businesses not subject to the same regulations as those that analyze human DNA?
Science chatted with Lisa Moses, a veterinarian affiliated with Harvard Medical School in Boston, and Elinor Karlsson, director of vertebrate genomics at the Broad Institute in Cambridge, Massachusetts. Both are authors on an opinion piece published today in Nature about these and other potential issues with the booming pet genomics industry. This interview has been edited for clarity and length.
Q: What kind of pets are being tested?
Lisa Moses: It’s overwhelmingly dogs. There are some tests for cats, but right now it’s about 90% dogs.
Q: Why would an owner want to get their pet’s DNA tested?
Elinor Karlsson: A lot of dog owners are interested in what breeds are in their dog, or some fun facts, like how big their dog could get. But there’s also testing for somewhere between 100 and 200 different genetic variants that have been linked to disease.
Q: Is the process of testing a dog’s DNA different from testing a human’s?
E.K.: Dogs and humans are very similar to one another, so you can use the same technology to look at dog DNA or human DNA. With these direct to consumer tests, for dogs or humans, often you’re not looking at every single part of the genome. You’re just looking for changes, or mutations, that are linked to some kind of disease or condition.
Q: How accurate are the tests for dogs that are now on the market?
E.K.: With genetic tests for humans, there have been so many studies that look at whether or not a certain mutation in your genes actually leads to you developing a certain disease. There just isn’t this massive body of work on dog genomes. So many of these tests are telling owners that their dog could get a certain disease without any major studies on how likely that is to happen. The science needs to catch up.
Q: What are the dangers of potentially inaccurate test results?
L.M.: In my veterinary practice, I’ve seen more and more people coming in with results that show their dog has a chance of developing conditions like epilepsy, heart disease, and degenerative muscular disorders, and they want to make treatment decisions right away. They’re ready to pay for more tests or medical interventions that the dog might not actually need, that could be quite expensive, and that could be invasive for the dog. In some cases, people preemptively end their dog’s life if they think their dog is predisposed to a degenerative disease, because don’t they want their pet to suffer.
Q: Genetic testing kits for humans are regulated. Why aren’t pet tests?
L.M.: With any new technology, regulation often lags behind, and for humans, there’s been more time for conversations to take place, and rules have been established that govern how the tests are vetted. With veterinary medicine, there hasn’t been a formal and systematic discussion about the ethics related to these new technologies. We need to start talking about this, because right now a lot of people are in the dark.
Q: What might happen if this industry continues to go unregulated?
L.M.: I worry that if the tests don’t improve, people are going to notice that their dogs don’t actually get the diseases they’re at risk for. I don’t want people to lose the idea that there is tremendous value in genetic testing, if we do it right. We really do have the potential to figure out that our patients get diseases long before they do permanent damage, if we are able to make this happen.
Q: How can we improve genetic testing for pets?
L.M.: We need to start with a conversation that encompasses the international veterinary community, the testing industry, and the scientists. We have to come up with some mutually agreed upon ways to report these results, and figure out how to validate them. We’d need to have transparency on how the tests are done, how the science is done, and talk seriously about data sharing. There’s a consortium, the International Partnership for Dogs, and they’re trying to do some standardization and data sharing. But, it’s brand new and I don’t know yet how successful they’re going to be.
Q: What kind of things could we learn from pet genetics, if we do it right?
E.K.: Dogs carry a lot of the same diseases humans do. By studying dogs, we could learn a lot about the causes of things like cancer, or diabetes, and use that information to develop new treatments for humans.