Zoology | A dog can smell if a person is stressed

Canine the sense of smell has been used in the search for explosives, drugs and cancer. Still, the dog’s accuracy never ceases to surprise.

A recent study revealed that a dog can even smell if a person is stressed. The study was published by Queens University Belfast science journal Plos One.

Four the dog was trained to identify pieces of fabric containing sweat and breath samples.

The dog was first allowed to sniff a piece of cloth, after which it had to find a similar piece of cloth among others.

The dogs recognized the correct sample, even if it was placed next to it in adjacent containers with pieces of cloth that had not been put in a sample or that had been sampled from the same person at a different time.

When the dogs understood what was wanted from them, the actual experiment began. It involved 36 volunteers, all of whom were asked to list numbers from 9,000 down in 17-digit increments.

The participants reported that the calculation was stressful. 27 of the volunteers did the experiment in the laboratory. Their blood pressure and heart rate were observed to increase.

Sweat and breath samples were taken from the volunteers twice, before and during the calculation. The samples were taken to the dogs to find out if the dogs distinguished the samples from each other and from the unused sample fabrics. Each set of samples was shown to each dog 20 times.

Result was impressive. The dogs correctly identified the samples taken from the stressed 675 out of 720 times.

“The study shows that dogs do not need visual or auditory perception to detect human stress,” says the first author of the study, PhD researcher Clara Wilson in the university’s bulletin.

It was the first experiment that showed that a dog can smell stress. Wilson hopes that its results can be used in the future, for example, in the training of therapy dogs.

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