A New Study Says Your Stress Can Spread to Your Dog

Most dog owners find their pets to be great stress busters. Curling up on the couch with your pug or playing catch with your Labradoodle is a great way to unwind and let the cares of the day slip away. But new science has some bad news for dog owners. Dogs might ease your stress, but they can also catch it.

An Interspecies Contagion

It's an old joke that dogs resemble their owners, but according to this new study out of Linköping University in Sweden, it's actually true in one less funny way: Stressed out owners have stressed out dogs.

To figure this out, the researchers took hair samples from 25 border collies and 33 Shetland sheepdogs, as well as their female owners. For both humans and dogs, hair records the level of the stress hormone cortisol in the body over time. So by analyzing these hairs, the team could figure out just how much stress both the owners and their pets were under long-term.

The study found the stress levels of the dogs and their owners matched up: Higher levels of stress among owners showed up as higher levels of stress in their dogs. The effect was even more pronounced if the dog was female or if it took part in agility competitions with its owner.

Previous research has found that cortisol in humans and their dogs can rise together in the short-term, especially when competing. But this finding was something new. "This is the first time we've seen a long-term synchronization in stress levels between members of two different species. We haven't seen this between humans and dogs before," lead researcher Lina Roth told the Guardian.

And what about a pooch's lifestyle? Did limited opportunities for play or more time spent alone stress out the dogs? Not nearly as much as belonging to a human with high cortisol levels. The personality of the owner seemed to play a role too, although that varied with the sex of the dog. Female dogs whose owners had higher scores in the Big Five traits of neuroticism, openness, and conscientiousness had higher cortisol levels, while the same was true of male dogs whose owners scored high in agreeableness.

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Don't Feel Guilty

This will not come as a huge surprise to many observant folks who have noticed that highly strung people often have highly strung dogs. But should scientific confirmation of this connection between owners and their dogs put you off having a pet if you're anxiety-prone? Or if you're under a lot of stress and already a pet owner, should you feel guilty?

Nope, replies Roth. "I don't think you should be anxious that, if you're stressed, you might harm your dog," she told NPR. "Instead, your dog is a social support for you, and you are a social support for the dog." Your stressed-out state can be more than made up for by extra pats, belly rubs, and tennis ball throws.

Though if you do lean towards the anxious side, you might want to think carefully about choosing a more laid back and resilient type of dog. Just which breeds are best is still an open question, one Roth and her collaborators hope to look into next.

It may "be possible to match dog and owner in a way that is better for both, from a stress-management point of view," she says. "It may be that certain breeds are not so deeply affected if their owner has a high stress level."