Washington D.C [USA], June 10 (ANI): Remember in 'Friends', when Phoebe gets Joey the happiest dog in the world to cheer him up? However, Joey ends up getting the dog all depressed? Well, now we have an explanation. According to researchers, Dogs tend to mirror their human's stress level.

Stress levels in dogs are influenced by the people they live with, the findings suggest.

As part of a study, researchers examined how stress levels in dogs are influenced by lifestyle factors and by the people they live with.

Previous work has shown that individuals of the same species can mirror each others' emotional states. There is, for example, a correlation between long-term stress in children and in their mothers.

The study, recently published in the Journal of Scientific, reports arose from scientists speculating whether similar mirroring of stress levels over long time periods can also arise between species, such as between the domesticated dog and humans.

The researchers determined stress levels over several months by measuring the concentration of a stress hormone, cortisol, in a few centimeters of hair from the dog and from its owner.

"We found that the levels of long-term cortisol in the dog and its owner were synchronised, such that owners with high cortisol levels have dogs with high cortisol levels, while owners with low cortisol levels have dogs with low levels," said Ann-Sofie Sundman, lead author of the study.

The study examined 25 border collies and 33 Shetland sheepdogs, all of them owned by women. The owners and the dogs provided hair samples on two occasions separated by a few months.

Since physical activity can increase cortisol levels, the researcher also wanted to compare companion dogs with dogs that competed in obedience or agility. The physical activity levels of the dogs were therefore recorded for a week using an activity collar.

The study found that the stress level of competing dogs seems to be linked more strongly with that of the owner.

The scientists speculate that this may be associated with a higher degree of active interaction between the owner and the dog when they train and compete together. (ANI)

