Dogs are as reliable as laboratory tests for detecting COVID-19 cases, and may be even better than PCR tests for identifying infected people who don’t have symptoms. A bonus: The canines are cuter and less invasive than a swab up the nose.
In a study involving sweat samples from 335 people, trained dogs sniffed out 97 percent of the coronavirus cases that had been identified by PCR tests, researchers report June 1 in PLOS One. And the dogs found all 31 COVID-19 cases among 192 people who didn’t have symptoms.
These findings are evidence that dogs could be effective for mass screening efforts at places such as airports or concerts and may provide friendly alternatives for testing people who balk at nasal swabs, says Dominique Grandjean, a veterinarian at the National School of Veterinary Medicine of Alfort in Maisons-Alfort, France.
“The dog doesn’t lie,” but there are many ways PCR tests can go wrong, Grandjean says. The canines’ noses also identified more COVID-19 cases than did antigen tests (SN: 12/17/21), similar to many at-home tests, but sometimes mistook another respiratory virus for the coronavirus, Grandjean and colleagues found. What’s more, anecdotal evidence suggests the dogs can pick up asymptomatic cases as much as 48 hours before people test positive by PCR, he says.
I can totally believe that dogs are capable of doing this, though as the study notes it’s not clear what exactly they’re picking up on. I’m just not sure what the practical use of this knowledge is. What are the circumstances under which dogs would be deployed to sniff for COVID, and how could it be done in a way that was non-invasive and respectful of people’s privacy? I’m a big believer in requiring negative COVID tests for a variety of things, but those should be allowed to be done at home and in private. I can’t imagine turning someone away from an event or whatever for failing a sniff test. But maybe there’s a good way to do this now that we know that it’s possible.