Dogs can detect odour changes in stressed individuals
Dogs can pick up the smell of stress from human sweat and breath – a fact confirmed by researchers from Queen’s University Belfast (Queen’s), based on a small study on humans and dogs. The “super-sniffer” dogs – named Treo, Fingal, Soot, and Winne – were trained to identify a particular scent associated with stress from a line-up of 36 participants.
In the study, researchers collected samples of sweat and breath from participants before and after they did a difficult maths problem. The participants had self-reported their stress levels before and after the task, however, researchers only used samples where the participant’s blood pressure and heart rate had increased.
The four dogs were each introduced to the stress and relaxed samples, taken only four minutes apart. All of the dogs were able to correctly alert the researchers to each participant’s stress sample.
“The findings show that we, as humans, produce different smells through our sweat and breath when we are stressed and dogs can tell this apart from our smell when relaxed – even if it is someone they do not know,” stated Clara Wilson, a postgraduate student in the School of Psychology at Queen’s.
“The research highlights that dogs do not need visual or audio cues to pick up on human stress. This is the first study of its kind and it provides evidence that dogs can smell stress from breath and sweat alone, which could be useful when training service and therapy dogs.
“It also helps to shed more light on the human-dog relationship and adds to our understanding of how dogs may interpret and interact with human psychological states.”
Helen Parks, the owner of two-year old Treo, a Cocker Spaniel, was elated.
“As the owner of a dog that thrives on sniffing, we were delighted and curious to see Treo take part in the study. We couldn’t wait to hear the results each week when we collected him. He was always so excited to see the researchers at Queen’s and could find his own way to the laboratory. “The study made us more aware of a dog’s ability to use their nose to “see” the world. We believe this study really developed Treo’s ability to sense a change in emotion at home. The study reinforced for us that dogs are highly sensitive and intuitive animals and there is immense value in using what they do best – sniffing!”