Dogs Notice Human Stress Earlier And Accurately Than Humans

Scientists have confirmed that dogs are able to detect human stress by smell. Dogs in general determine human stress accurately than people themselves, writes Earth.com. The study was published in the journal Animal Cognition.

A study from the University of Naples Federico II (Italy) showed that trained dogs distinguished between calm and stressed with 93.75% accuracy, responding to changes in the chemical composition of exhaled air and sweat.

This sense of smell is explained by the structure of the brain: in dogs, the olfactory bulb occupies about 0.31% of the brain volume, while in humans it is only 0.01%. Many breeds have than 220 million olfactory receptors that can detect the slightest chemical signals.

In the experiment, participants performed a stress-inducing task, after which scientists collected samples of their sweat and breath. These samples containedvolatile organic compounds that change with increased heart rate and blood pressure.The dogs were excellent at distinguishing between “stressful” and neutral odors even in a test tube, confirming that they sense human physiological reactions and do not “read minds.”

The smell of tension

For dogs, scent is another layer of information that complements body language and voice. It influences behavior even when a person appears calm.Owners often notice that a dog may become wary around a quiet and polite guest – simply because it senses the smell of tension.

The sense of smell is also associated with memory: dogs form lasting associations and retain them for a long time. A neutral smell, once associated with something bad, can make you wary the next time you encounter it.

This characteristic becomes the basis of the work of service dogs trained to help people with post-traumatic stress disorder. In one study, veterans who received trained assistance dogs showed lower anxiety levels and better daily functioning scores after three months compared to a control group.

Scientists emphasize that sudden growling or avoidance is not aggression, but a reaction to an odor signal. This can be corrected using gentle methods, forming new associations.

Punishment only increases stress. Experts recommend that owners monitor the context, reduce the load on the dog and, if necessary, turn to trainers who work on positive reinforcement.