How do dogs smell feelings of stress in their owners?

Four dogs were trained to "choose" a package of three different scents.

In more than 650 out of 700 experiments, dogs successfully identified a sample of sweat or breath from a stressed person.

Researchers at Queen's University Belfast hope that their study, published in the scientific journal "Plos One", will help train dogs for therapeutic purposes.

• Dogs have evolved the looks of their eyes to win over people's feelings
• Dogs have been humans' best friends for 11,000 years

And dogs explore their world through smell. Its capabilities have already been used to detect drugs, explosives and diseases, including some types of cancer, diabetes and even Covid.