TRENDING SCIENCE: Feeling stressed? Your dog can smell it

We know that our four-legged friends experience their surroundings through smell. They have about 220 million odour-detecting cells, compared to our 50 million. Over the years, we have been benefiting from canines’ formidable sense of smell. They help us sniff out drugs, explosives, certain medical conditions and even coronavirus infections. But human stress?

A research team at Queen’s University Belfast in the United Kingdom has figured out at least one way how. According to findings published in the journal ‘PLOS ONE’, dogs can smell stress. That’s because our bodies give off a distinct odour when we’re stressed. More specifically, they identify stress from our sweat and breath.“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,” explained first author Clara Wilson, a PhD student in the School of Psychology at Queen’s, in a news release by the same university. “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 … .”

Wilson added: “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.”

A cocker spaniel, a cockapoo, two mixed breeds and 36 people participated in the study. The researchers took breath and sweat samples from the humans while feeling neutral and while experiencing a state of stress. The volunteers reported their stress levels before and after completing a challenging maths problem.

The four dogs were trained to select one of three scent containers. Each container held a sample of the participants’ sweat or breath from before or after. In 675 out of the 720 trials (94 %), the dogs successfully identified a sample of sweat or breath that had been taken from a stressed person.

Wilson told ‘The Guardian’ that the research could prove useful for training service dogs and therapy dogs. “They’re often trained to look at someone either crouching down on the floor, or starting to do self-injurious behaviours. There is definitely a smell component, and that might be valuable in the training of these dogs in addition to all of the visual stuff.”You might want to reconsider if you’re one of those people who looks strangely at pet owners claiming their dogs know exactly how they’re feeling and will even try to provide comfort. Dogs make good emotional therapy animals, but do they actually feel empathy when their owner is stressed?

One day, research may provide an answer to this question, too. Dog lovers won’t need science to convince them.