Can dogs smell, smell stress? Do dogs know if we are stressed or sad?

Have you ever wondered how your mood can affect others? Your peers aren’t the only species in your immediate environment to notice your increased stress levels, according to new research.

While most of us observe signs of stress through what we see and hear, our dogs are equipped with their own additional tool for identifying this mood swing in humans – their snoots.

According to a recent study published in the scientific journal PLOS ONE, dogs are not only able to sense a human’s mood swing, but they are also able to detect stress through smell. The study concludes that our beloved canine friends have the ability to distinguish between stress levels via our scent – specifically the smells associated with our breath and sweat.

“The dogs were able to discriminate, with a high degree of accuracy, between human breath and sweat samples taken at baseline and during psychological stress,” the study authors wrote.

So what does this mean exactly? Clara Wilson, study author and doctoral student at the School of Psychology at Queen’s University Belfast in Ireland, told Gizmodo that “the take-home message from this study is that our body’s psychological stress response alters the smell of our breath and our sweat. , and dogs can detect this change.

Essentially, your breath and sweat literally smell different when you’re stressed, and your furry friend can tell.

William, a dachshund mix

William, a dachshund mix. William did not participate in the study.

In order to test the dogs’ stress-sensing abilities, the researchers recruited 4 dogs and 36 humans for the study’s testing process, Smithsonian Magazine reported. The study method used two saliva samples from the three dozen human participants, one being a baseline control and the other being a “stress” sample. The “mild stress-inducing” test sample was collected after participants participated in a “mental arithmetic task”, according to the study.

The four dogs used in the experiment “were able to detect with greater than 90% accuracy which samples came from before and which came from after the 36 human volunteers spent three minutes trying to count backwards, aloud. , starting at 9,000 in 17” units, according to NBC News.

So the next time your pooch looks you deep in the eye or gently offers his paw to you, it wouldn’t hurt to take a moment to assess your mood – your furry friend may be sensing your stress and trying to calm you down. .


Kat, a mixed breed rescue dog. Kat did not participate in the study.