Editor’s note: As COVID-19 continues to spread worldwide, scientists are analyzing new ways to track it. One promising approach is training dogs to detect people who are infected by smelling samples of human urine or sweat. Research scientist Glen Golden, who has trained dogs and ferrets to detect avian flu in birds, explains why certain animals are well suited to sniff out sickness.
1. Which species have a nose for disease?
Some animals have highly developed senses of smell. They include rodents; dogs and their wild relatives, like wolves and coyotes; and mustelids – carnivorous mammals such as weasels, otters and ferrets. These species’ brains have three or more times more functional olfactory receptor neurons – nerve cells that respond to odors – than species with less keen smelling abilities, including humans and other primates.
These neurons are responsible for detecting…