In a test to see if dogs can identify material that has been exposed to breath and sweat from stressed humans, they got it right around 94 per cent of the time.
Dogs can smell the difference between stressed and relaxed humans from their sweat and breath alone. The finding could be used to inform training programs for service dogs.
When we are stressed, our body responds with a host of physical changes. Our heart rate jumps, we get clammy and the cocktail of chemicals in our sweat and saliva changes. Studies have found that dogs can smell things like fear and distress in humans by detecting these chemicals.
When a dog breathes, about 12 percent of her air intake is directed into the specially designed smelling chamber. Within this area, the air fills hundreds of tiny tubs. These tubs sieve odor molecules based on their chemical makeup. This allows dogs to literally break down the air around them and detect even the smallest molecules.
This unique characteristic allows dogs to pick up on signals of fear and stress. Not only can they smell better than us, but they can pick up on chemicals that we just can’t.