TORONTO -- Creating a fast and reliable test to detect COVID-19 has been expensive and challenging, but new research suggests a cheap and effective solution could be right under our noses â or rather, dogsâ noses. Specially trained dogs are highly effective at sniffing out the presence of COVID-19 in human sweat, according to a new study, which bolsters existing evidence and suggests that dogs could play a key role in efforts to control the virus. The proof-of-concept study in France and Lebanon trained six dogs for a month to detect the smell of patients whoâd been sickened by the novel coronavirus. Researchers took sweat samples from more than 170 people, about half of whom were COVID-19 positive, and tested whether the dogs could differentiate between sick and healthy patients.