“P.C.R. tests are not immediate, and there are false negative results, while we know that dogs can detect COVID in its incubation phase,” said Dr. Anne-Lise Chaber, an interdisciplinary health expert at the School of Animal and Veterinary Sciences at the University of Adelaide in Australia who has been working for six months with 15 COVID-sniffing dogs.
Some methods of detection, such as temperature screening, can’t identify infected people who have no symptoms. But dogs can. That’s because the infected lungs and trachea produce a trademark scent. And dogs need fewer molecules to nose out COVID than are required for P.C.R. testing, Thai researchers said.