The smell of Covid-19: Thai sniffer dogs can detect it in sweat

Thai sniffer dogs trained to detect Covid-19 in human sweat have proved nearly 95% accurate during training and could be used to identify sick people at busy transport hubs within seconds, the head of a pilot project is reporting.

Six labrador retrievers were put through a six-month programme that included training them to sniff out an infected patient’s sweat from a choice of six vessels.

“The dogs take only one to two seconds to detect the virus,” Kaywalee Chatdarong, the leader of the project at the veterinary faculty of Thailand’s Chulalongkorn University, told Reuters.

“Within a minute, they will manage to go through 60 samples.”

The dogs’ superior sense of smell enables them to detect tiny amounts of a volatile organic compound secreted in the sweat of Covid-19 sufferers, even in the absence of disease symptoms, the Thai researcher said.

The dogs would not need to directly sniff people, but could screen samples of sweat, a task that should not be difficult in a tropical country such as Thailand, she added.

“The next step is we will put them out in the field,” said Kaywalee. “In the future, when we send them to airports or ports, where there is an influx of commuters, they will be much faster and more precise in detecting the virus than temperature checks.”

Other countries including Chile, Finland and India have also launched projects to train sniffer dogs to detect the virus, with a German veterinary clinic saying last month its sniffer dogs had achieved 94% detection accuracy in human saliva.

Thailand has been relatively successful in containing the virus, with a new wave of infections in the first two months of the year now levelling off.

It has also started vaccinating front-line health workers and hopes to find a way to let visitors return in greater numbers to revive its tourism-dependent economy, battered by the pandemic.