Dogs, trained to sniff Covid-19 from people's sweat debuted at Chile's International airport on Tuesday. The canines are a part of the government's alternative, cost-effective method of identifying passengers with the virus. The canine brigade, who will be at work at the Santiago International Airport, comprises four dogs who can sniff up to 250 people an hour. They have been trained to detect various types of smells in human sweat and therefore detect someone who has Covid-19.