They Can Smell Stress

Science Fields

What can’t our furry friends do? A new study shows that dogs can smell when we’re feeling stressed. 

Clara Wilson who is a final year PhD candidate at Queen’s University Belfast and colleagues recently did a study investigating dogs’ ability to distinguish odors caused by stress from normal odors. The research focused on canines suggests that dogs can draw important information from what they smell in their environment. Through their sense of smell, canines are also able to successfully keep out of harm’s way. 

For this study, Wilson and the research team collected breath and sweat samples from volunteers before and after a stress-inducing task. The study participants were composed of non-smokers and they were not supposed to eat or drink before the study. To increase stress levels, the researchers gave the participants a fast-paced arithmetic task to complete. These poor volunteers had to count backward from 9000 in units of 17, out loud, in front of the two researchers without the aid of a pen or paper. Physiological markers of stress like heart rate and blood pressure were also measured. 

Samples from the participants who reported an increase in stress, heart rate and blood pressure during the arithmetic task were then shown to dogs to smell. The dogs that were included in the study were no ordinary dogs, however. They were actually trained to find the sample from a stressed-out participant while the same person’s relaxed sample was also present in the line up. 

According to the researchers, acute psychological stress creates changes in the odor profile of our breath and sweat. Furthermore, the findings of the study reveal that dogs are able to detect this change with a 93.75% accuracy. 

It is possible that an odor component may be useful as a training aid for service dogs tasked with responding to acute stress responses in their owner,” the authors of the study explain. 

Now, Wilson and colleagues are eager to see how untrained dogs might do on the smell task. 

What do you think? 


  • 1. KAYNAKLAR Wilson, C., Campbell, K., Petzel, Z., & Reeve, C. (2022). Dogs can discriminate between human baseline and psychological stress condition odours. PLOS ONE, 17(9):e0274143 DOI: 10.1371/journal.pone.0274143
  • 2. https://www.sciencedaily.com/releases/2022/09/220929133419.htm