If you're a dog lover, just being with your pet feels good.

So it's no surprise that therapy dogs are healing companions for people with health conditions such as cancer, post-traumatic stress syndrome, and dementia.

There are over 50,000 therapy dogs in the United States, and they're becoming more popular in countries from Norway to Brazil. Trained and certified by a variety of organizations, these dogs and their handlers go into hospitals and other facilities and interact with patients.

A recent study in Applied Animal Behaviour Science reports that therapy dogs in pediatric cancer wards are not stressed by their "work," and in fact seem to enjoy it in most cases.

"What made this study unique was that it was multisite—it took place in five different hospitals across the country—and the fact that we visited over a hundred patients and 26 dogs participated, making it the largest of its kind in this field," says study leader Amy McCullough, national director of research and therapy at American Humane, a Washington, D.C.-based animal welfare organization.

Working Like a Dog

The researchers measured levels of cortisol, a hormone elevated in response to stress, in the canines' saliva. The swabs were taken both at home and during therapy sessions at the hospital.

However, cortisol level rise with both good and bad stress. "Let's say we have a dog that loves to play ball—when the ball comes out and the dog starts chasing the ball, that would elevate the dog's cortisol levels as well," McCullough says.

So the team also videotaped and analyzed 26 canine behaviors in three categories: friendly actions such as approaching a person or play-bowing; moderate stress indicators such as lip-licking and shaking; and high-stress behaviors like whimpering. (Read more about why dogs are so friendly.)

Dogs Change Facial Expression When Humans Pay Attention



Click here to read Dogs Show 'Sad Puppy Face' More Often When Being Watched. Oct. 19, 2017 - Dog faces don't just make for great internet videos—they can also teach us about the evolution of dog domestication. A new study shows that when given human attention, dogs will produce a wider range of facial expressions. Scientists gauged dog reactions while being watched by a human versus when the human had their back turned. While being watched, the dogs used a wider variety of facial movements. Dogs have lived alongside humans for 30,000 years, and may have evolved this ability to better communicate.

The scientists found no difference between the study dogs' cortisol levels at home and at the hospital, evidence that the therapy dogs were not particularly stressed.

Making Work Fun

The finding is consistent with previous research, according to Lisa Maria Glenk, author of a 2017 review of the literature on therapy dog welfare.

The "well-designed" study is particularly valuable for its level of detail: "Previous studies provided only limited or no information on session activities, which makes it hard to identify the practices that raise stress levels in dogs," says Glenk, of Vienna's University of Veterinary Medicine.

The next question is whether therapy dogs actually enjoy their work, she says—and the new pediatric cancer study provides a few hints. (Your dog knows how you feel—here's how.)

For example, dogs seemed happier during some activities than others; a child talking to the dog or playing with its toy, for example, seemed to elicit more friendly responses than a child brushing the animal or drawing it.

Looking at the results, "it's fair to say that some activities are more fun for the dog," McCullough notes.

"This is good information for handlers—they can lean toward the activities that they think their dog would enjoy."

Finding a Natural Fit

That requires observing therapy dogs closely, even if they can seem inconsistent at times. For instance, the study found that the dogs who showed the most stress behaviors also showed the most friendly behaviors, suggesting that some canines may just be more obvious about their feelings. (See some of our favorite dog pictures.)

Like with any job, it's important to choose the right candidates, McCullough adds. Many people want to share their pets' affection with their local communities, "but that doesn't mean their dog is cut out for this kind of work."

So therapy dog trainers and certifiers, as well as owners, need to look for enthusiasm, not mere tolerance.

"Does the dog solicit attention, or does the dog need to be bribed with treats to interact?" she says.