According to university professor and veterinary epidemiologist, Fernando Mardones from the Catholic University of Chile, “A body that contracts Covid-19 generates volatile organic compounds. A sample is taken from a person in the early stages of the infection. A gauze is left for about 15 minutes on an individual’s underarm. That’s the sample we store and use to train the dogs with.”
That being said, it should be noted that at the moment, there is no evidence to suggest that dogs will be capable of sniffing out the coronavirus, so it will be interesting to see how effective this training program will be. At the moment, it is a pretty small program with about four puppies in training, but presumably if successful, would see it expanded.
Colonel Julio Santelices from the Chilean police adds, “A dog can detect, in an hour, it can sniff 250 people. So when we begin opening stadiums, schools, businesses, restaurants, it will be essential that in those places that are being opened, as we seek normalcy, we can now add our bio-detector dogs.”