A number of studies using dogs to sniff out the coronavirus are underway around the world.
Researchers at the London School of Hygiene & Tropical Medicine have teamed up with a group that trains the animals to use their far superior sense of smell to detect diseases.
Last month, they said the first phase of a trial showed that six dogs were highly effective at detecting the coronavirus in odor samples taken from about 3,000 people.
Similar studies are underway at the University of Pennsylvania in the United States, and Chulalongkorn University in Thailand.
Dogs are being used on a trial basis at an airport in Finland to detect people who require testing.
Experts at the University of London say the animals have the potential to become a way of quickly identifying asymptomatic people.