Sinatra is restless. He circles a sample of cotton while barking, digging and sniffing. He didn’t end up there by chance, and it’s not the first time he has behaved like this, either. Strong and sharp-eyed, the spotted mutt is trained to sniff out traces of the novel coronavirus. Sinatra is an advanced student at what’s effectively a school for “coronavirus sommeliers” here in the Brazilian city of Campo Limpo Paulista, 40 kilometers (25 miles) from São Paulo. He is part of a pair already trained to identify people infected with the virus; another 11 dogs are also being trained. Dogs are immune to COVID-19, and they have a powerful olfactory system — about 300 million olfactory receptors compared to the 5 millions in humans. They have 40 times the capacity to assimilate odors, and this means that around the world they’re employed by scientists looking for quick and practical methods to identify human hosts of the virus. Several studies have proved their talent. At Hannover Medical School, Germany, researchers are advancing the testing of sniffer dogs for volatile organic compounds. In other European countries, results from similar research are also promising. In October, a trained pack was photographed at the Helsinki airport in Finland, apparently sniffing for signs of coronavirus infection. In Brazil, Anísio Francisco Soares is the head researcher for dogs at the Federal Rural University of Pernambuco (UFRPE). He explains how dogs’ sense of smell can help them identify infected individuals: “It is important to remember that…This article was originally published on Mongabay Läs mer