Sniffer dogs trained at Vancouver Coastal Health can now detect COVID-19 on humans

Three new sniffer dogs can detect COVID-19 on people at rates superior to some antigen tests, according to Vancouver Coastal Health.

The dogs are part of the Canines for Care program at the health authority, which usually trains dogs to detect Clostridium difficile, also called C. difficile, a "superbug" and a common cause of diarrhea in hospitals and long-term care facilities.

Six months ago, however, two Labrador retrievers, Micro and Yoki, and an English springer spaniel, Finn, were brought in and trained to detect the novel coronavirus.

VCH says that Micro and Finn were found to have 100 per cent sensitivity and 93 per cent specificity in identifying the virus, validated by a third party reviewer in a lab, with Yoki also going through a "rigorous" validation process.

"We've been using samples that are coming from sweat, gargles, and also breath samples to train the dogs," said Dr. Marthe Charles, medical microbiologist with Vancouver Coastal Health.

"My hypothesis at this point is that the dog has the ability of not only smelling the impact of COVID on your body, but also your body's response to the virus."

Health Canada has provided $200,000 to the program as part of the "safe restart" program announced last summer.

Dr. Charles says VCH is in conversation with the federal department regarding where the dogs can be deployed, noting that sniffer dogs are currently used primarily at airports and big sporting events.

'Game of association' for sniffers

Teresa Zurberg, Finn's owner and canine detection specialist at the health authority, says the dogs were trained with "several thousand" samples from consenting COVID-19 patients.

"For the dogs, any detection work, whether it be a bomb dog, a drug dog or COVID dogs, it's a game for them. It's a game of association," she said.

"They learn if they find what we want, which is whatever target odour we choose [...] they get what they really want, which is a toy or food."

Zurberg showed CBC News how Finn, the two-year-old spaniel, can sniff out COVID-19 by selecting the correct funnel-shaped "scent stand" containing the target odour. After the dog investigated all the stands and put his head in the correct funnel, he was given a release command and then a treat.

"We've taken dogs that have never been trained on any other odours before," she said. "So when [Finn] alerts, I know exactly, 100 per cent, he's alerting on COVID and not another odour."

Charles says the samples used to train the dogs were prepared in a way that ensured the research team was not at risk of transmission.

She also said that the findings were superior to some mass-market antigen tests and said research would continue on the project.

"We're only limited by our imaginations as to what we can get dogs to sniff for," said Zurberg. "The fact that they can sniff viruses and tell the difference between viruses just blows my mind."