In Germany, a new study found that dogs, if properly trained, were able to smell the difference between human saliva samples infected with SARS-CoV-2 versus non-infected samples, with 94% accuracy. Researchers from the University of Veterinary Medicine, Hannover, and the Hannover Medical School trained eight dogs from Germany's armed forces for one week. The dogs sniffed saliva of more 1,000 people that were either healthy or infected with Covid-19. Infected samples were distributed at random, and neither dog handlers nor researchers on site knew which ones were positive. Prof. Maren von Koeckritz-Blickwede, who conducted the study, said they hypothesize that dogs are able to do this because the metabolic processes of an infected person "completely change." Dogs also have smell receptors up to 10,000 times more powerful and accurate than humans'. "That allows certain trained dogs to sniff out diseases like cancer, malaria and viral infections," CNBC reports.