Original Article: https://blog.theanimalrescuesite.greatergood.com/dogs-smell-human-stress/

Dogs have been taught to detect many smells over the years. In doing so, they’ve been enlisted to sniff out drugs, cadavers, bombs, destructive insects, diseases, changes in blood sugar levels, and even oncoming epileptic seizures. Now, it’s been discovered that dogs are able to detect stress in a person’s breath or sweat with nearly 94 percent accuracy. It would make sense that if an animal can smell fear, surely it can smell rising stress levels.

According to the journal PLOS ONE, researchers in the U.K. determined that dogs could detect psychological or emotional stress in an individual’s sweat and breath with an accuracy of 93.75 percent. A group of 20 dogs was recruited for the study. As training wore on, however, some of the animals ended up being eliminated for various reasons, including a general lack of interest over time. In the end, four were able to complete one hour of training each week over a period of roughly 10 months.

Animal Research

The results demonstrated that physiological processes associated with stress create changes in compounds emanated from either breath, sweat, or both and that dogs are quite capable of recognizing these changes. The study’s lead author, Clara Wilson, admitted to Medical News Today, “It was fascinating to see how able the dogs were at discriminating between these odors when the only difference was that a psychological stress response had occurred.”

Wilson also added that the training was “very extensive, as the premise was that the dogs needed to be consistently able to discriminate between two very similar human odors with known differences at above 80 percent correct for multiple sessions.”

Sniffer Dogs

In the initial phase, dogs were to identify one of three containers with a food and sweat sample inside. Researchers then removed the food and presented the canines with three ports. One contained human sweat and breath, while the others held nothing. The animals had to identify which of the three held the sample.

Humans then provided sweat and breath samples along with self-reporting questionnaires outlining the level of stress they were experiencing prior to completing a mental math problem. They had to provide another sample once the task was completed. The canines were then presented with a sample from a stressed participant as well as two blank samples.

Scent Training

The dogs had to further demonstrate their olfactory superpowers, but you get the point: their sniffers are far superior to ours when it comes down to a numbers game. If you’d like to engage your pup in some mental stimulation involving scent training, there are simple ways to go about it that are fun. You don’t need expensive equipment or fancy anything. Teaching them can be done with common household items you likely already have, plus some treats, of course. The best part about it is you’re creating a bonding experience, even if they show no aptitude whatsoever and fail miserably.

Source: The Animal Rescue Site Blog