Stress smells of its own and dogs can sense the change, says a study led by Queen's University in Belfast, Northern Ireland, which observed four dogs being able to spot, with 93.8% accuracy, sweat and breath samples taken after putting people through a stressful math test.
The research, published in the journal Plos One, sheds light on the close relationship between dogs and humans and also provides new information that can prove very important in training therapy dogs and guide dogs.
The researchers, led by Clara Wilson, recruited four dogs of different breeds for the experiment: Treo, Fingal, Soot and Winnie.
The results show that humans, when stressed, produce different smells through sweat and breath and dogs are able to tell them apart, even when it comes to someone they don't know.
In addition, the study highlights the fact that man's best friends do not need visual or sound cues to tell when a person is in a state of stress: this has implications for therapy dogs being paired with people, for example. with post-traumatic stress disorder (Ptsd), who are currently being trained to respond primarily to visual stimuli.
"This is the first study of its kind and provides evidence that dogs can smell stress from even breathing and sweat," comments Wilson.
"Furthermore, it helps shed more light on the human-dog relationship - adds the researcher - and allows us to better understand the ability of dogs to use their nose to 'see' the world and their way of interpreting and interacting with psychological states. humans ".