Special dogs could start screening humans for COVID-19 within weeks, experts say

May 7 (UPI) -- Researchers in the United States and Britain are looking into an intriguing possibility that's come out of the global COVID-19 crisis -- whether some dogs have an ability to literally sniff out the coronavirus disease in human patients.

If it's ultimately determined that certain canines have such a capability, they would aid mass testing efforts worldwide.

At the University of Pennsylvania School of Veterinary Medicine, or Penn Vet, a pilot training program with several dogs is studying their coronavirus potential.

Meanwhile, in Britain, the London School of Hygiene and Tropical Medicine and Durham University have partnered with Medical Detection Dogs to train a half-dozen canines to screen for the virus in human subjects.

Previous research has shown it highly likely that dogs have the ability to detect some medical conditions, including certain forms of cancer, neurological diseases, bacterial infections and malaria.

"The aim is that dogs will be able to screen anyone, including those who are asymptomatic, and tell us whether they need to be tested," said Claire Guest, co-founder and CEO of Medical Detection Dogs, a 12-year-old private organization that says it's at the "forefront of the research into the fight against cancer and helping people with life-threatening diseases."

Cynthia Otto, director of Penn Vet's Working Dog Center, said specialty "bio-detection" dogs often can accurately pick up unique scent signatures -- traces of a volatile organic compound, or VOC -- associated with diseases in humans.

"We think it's very likely that if there is an odor associated with COVID-19, a person that's infected will have that odor," she said.

That particular scent, Otto notes, might be produced by the virus or the manner in which it interacts with the human body.

To pick it up, if the scent exists, canines can be trained in laboratory settings by running through a series of smell tests involving a positive COVID-19 sample, experts say.

Researchers then must study whether dogs that pass the test also can tell the difference between a positive sample and a negative sample.

Because COVID19 is contagious, the study groups must train the dogs with a deactivated viral sample.

Also, canines will sniff only the air around a human test subject, without making physical contact. Because it's estimated that dogs have a sense of smell and olfactory analytical capabilities many times greater than those of humans, experts believe contact isn't necessary for the trained canines to hit on a positive sample.

"[They] detect life-threatening diseases from sweat, breath, urine and fecal samples," Guest said.

Dogs trained to find the virus also could play a significant role in future coronavirus outbreaks if it re-emerges with a mutated formulation -- which some scientists say already has happened.

"If the research is successful, we could use COVID-19 detection dogs at airports at the end of the [pandemic] to rapidly identify people carrying the virus," Durham University public health Professor Steve Lindsay said.

"This would help prevent the re-emergence of the disease after we have brought the present [outbreak] under control," he said.

Guest and Otto said, however, that trained dogs already stationed at U.S. airports and other public places to find drugs and explosives would not make good candidates to sniff out the coronavirus. Because they're already trained to lock onto other smells, training them to find the virus likely would confuse them.

"Let's say we had a COVID-19 dog at an airport and it was screening for COVID-19, and it came up with a positive test alert," Otto hypothesized. "If that dog also was trained for explosives, it really confounds how we respond to that positive alert."

Once all the research is completed, Medical Detection Dogs said its dogs can be fully trained to perform human screening within eight weeks. And Penn Vet said canine-involved human screenings could begin as soon as July.

"This would be fast, effective and non-invasive, and make sure limited [hospital] testing resources are only used where they are really needed," Guest said.