Dogs act sad when they sense stress

Dogs act sad when they sense stress

Sarah Novak

Humans and dogs are supposedly close companions. 30,000 yearsAnthropological and DNA evidence suggests that dogs have a unique ability to interpret human emotions. They evolved to pick up on verbal and visual cues from their owners. Previous research It turns out dogs have a keen sense of smell and can even detect the smell of stress in human sweat, and now researchers have discovered that not only can dogs smell stress (in this case, indicated by elevated levels of the hormone cortisol), but they also respond emotionally to it.

In a new study published Monday, Scientific Reports, Scientists at the University of Bristol in the UK recruited 18 dogs of various breeds and their owners. Eleven volunteers who were unfamiliar with dogs underwent stress tests including public speaking and arithmetic, during which armpit sweat samples were collected on a piece of cloth. The human participants then performed relaxation exercises, such as sitting in beanbag chairs under dim lighting and watching a nature video, after which they collected a new sweat sample. Sweat samples from three of the volunteers were used in the study.

The dogs were divided into three groups and were trained to know that a food bowl in one location contained a treat and another did not. During the experiment, the food bowl without a treat was placed in one of three “ambiguous” locations. In one experiment, dogs that had sniffed a sample from the food bowl of a stressed volunteer were less likely to approach a food bowl in one of the ambiguous locations than dogs that had sniffed a cloth without a sample, indicating that the dogs thought that this food bowl did not contain a treat. Previous research Anticipation of a negative outcome has been shown to reflect a depressed mood in dogs.

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The results show that dogs become more pessimistic about uncertain situations when they are around stressed people, but this effect does not exist when they are near someone who smells relaxed, the researchers say. Zoe Parr-Cortes“For thousands of years, dogs have learned to coexist with humans and have done so alongside them for much of their evolution. Both humans and dogs are social animals and there is emotional contagion between us,” she says. “Being able to sense stress in other members of the pack would probably have been beneficial, as it would have alerted them to a threat that other members of the group had already sensed.”

The fact that the scent came from an unfamiliar person to the dogs speaks to how important smell is to animals and how it can affect emotions in such real-life situations, the researchers say. Katherine A. HauptHaupt, professor emeritus of behavioral medicine at Cornell University College of Veterinary Medicine, suggests that the smell of stress is known to affect appetite, so it may have reduced the dogs’ hunger. “It may not be that the smell of stress is changing the dog’s decision-making, but rather that it’s changing their motivation for food,” she says. “It makes sense because if you’re extremely stressed, you’re not going to be as interested in a candy bar.”

Haupt added that the study shows that dogs have an olfactory sense of empathy, in addition to visual and verbal cues. And stressed owners may behave in ways that dogs don’t normally display, he said. And it raises questions about how stress affects animals when combined with the pressures of anxious owners. “If dogs are responding to such mild stress, I’d be interested to see how they would react to something more serious, like an impending tornado, losing their job, or failing an exam,” Haupt said. “Dogs should be even more sensitive to real threats.”