You transfer your long-term stress to your dog, says new research

One definite way to keep your dog happy is to stay happy yourself. Not only acute stress is contagious but your long-term stress too starts reflecting in your dog. Swedish scientists have found this in a study tiled ‘Long-term stress levels are synchronized in dogs and their owners’ published recently in the journal Scientific Reports.

The scientists studied 58 dog-human pairs and analyzed their hair cortisol concentrations (HCC) levels during previous summer and winter months. Cortisol is a hormone released during stress. Acute cortisol levels can be assessed in blood and saliva, but long-term cortisol concentration is better assessed in hair, says the study.

Previously, synchrony of hair-cortisol concentrations has been found between mothers and their children. While there is already evidence of cortisol synchronization between handlers and their dogs during agility competition, this can partly be caused by the mutual physical activity during such a competition and does not necessarily reflect contagious effects of psychological stress, says the study.

“Here, we found synchronized long-term stress levels in dog-human dyads, containing both pet and competing dogs of two different dog breeds [border collies and Shetland sheepdogs], providing further evidence to the strong relationship between humans and dogs. Long-term stress contagion has previously been shown between human mothers and both their infants and their older children. However, this is the first study on long-term interspecies stress synchronization,” said the scientists in their paper.

Depression, excessive physical exercise and unemployment are just a few examples of stress that can influence the amount of cortisol found in your hair, Lina Roth of Linkoping University in Sweden, one of the scientists, told AP. She thinks the owners are influencing the dogs rather than the other way around. She said dogs influenced their owners rather than vice versa because people were a more central part of the dog’s life whereas humans also have other social networks.