Sniffer dogs, specially trained to detect people infected with COVID-19 who do not exhibit symptoms, will soon be sent to international airports and seaports to help identify asymptomatic cases among arrivals from abroad.

According to the Chula Journal website, the six Labrador retriever dogs, trained by a research team at the Veterinary Faculty of Chulalongkorn University, have a 94.8% accuracy in detection.

Professor Dr. Kaywalee Chatdarong, vice dean of the research and innovations section of the Veterinary Faculty and chief of the project, explained that all the thermal scanners or imaging systems installed at ports of entry or at public venues only detect higher body temperatures and no other symptoms and, therefore, are not effective in detecting asymptomatic cases.

Dogs’ noses, however, are 50 times more sensitive than humans and can detect asymptomatic cases through their sweat.

The project is a joint effort between the Veterinary, Medicine and Science faculties of Chulalongkorn University, with funding from the Chevron Company.

The research protocol involves the collection of sweat. Socks or cotton buds soaked in sweat are put in a germ-free lab and then put in a can to be sniffed by the trained dogs.

“When a dog kneels down, it means that the sample is from an asymptomatic case,” said Professor Dr. Kaywalee, adding that all the testing process is safe for the dogs and officials concerned.

The trained sniffer dogs’ accuracy is on par with the sniffer dogs used in Finland, Germany, France and Australia, she added.

Associate Professor Dr. Somporn Techa-ngarmsuwan, a veterinarian specializing in infectious diseases and a member of the research team, said that six dogs have passed the first stage of the training, which is about distinguishing the smells of infected and uninfected people and accuracy.

The second stage is actual practice, by having the trained dogs deployed at an international airport or a seaport to sniff the feet of incoming travellers. The final stage is about the development of sensor devices to detect asymptomatic cases.