‘Covid-19 has an odour, and the dogs are detecting it’: meet the canine super-squad sniffing out the virus

A single-storey building in a lonely rural business park, a few miles from Milton Keynes on a grey autumn day. It looks like a location for a bleak thriller: where a kidnap victim is held, perhaps, or the scene of a final shootout. Inside, though, something kind of cool is happening.

In a brightly lit room, four inverted metal cups have been placed on the red carpet, each containing a small glass jar. One of these contains a smell: a “training odour”. Into the room bursts Billy, followed by Jess. Billy is a labrador, and Jess his human trainer. Billy bounces about the place, clearly super excited. He sniffs at everything – furniture, people, the cups – wagging ferociously. When he sniffs at the cup that contains the smell, another trainer, Jayde, indicates success with a clicking noise. Billy is rewarded with his favourite toy, a well-chewed rubber ball, and a chorus of “good boy”.

So far, so unremarkable. Dogs have excellent noses, everyone knows that. They are estimated to be at least 10,000 times better than ours. It’s not immediately clear just how good Billy is. Did he really find the smell, or