A new literature review from a researcher at the University of Yale claims that there is no evidence that “pet therapy” actually works. Pet-therapy refers to the use of different animals in certain places or situations in which is believed they will help relax an individual.

The trend to use therapy animals has accelerated since it first started decades ago, and these animals can be seen anywhere from the San Francisco airport to hospitals. But some researchers are concerned that these practices are spreading without having any scientific evidence that supports their efficiency.

Image credit: Palomar Health
Image credit: Palomar Health

Molly Crossman from the University of Yale, who recently conducted a study involving an 8-year-old dog named Pardner, review the existent literature on the subject and cited “a murky body of evidence” that often has shown positive short-term effects, sometimes found no effect and occasionally found higher rates of distress.

There isn’t enough literature to support benefits of pet therapy

Crossman said that animals seem to be helpful in a “small-to-medium” way, but it’s unclear whether the animals were responsible for the improvement or something else was at play.

“It’s a field that has been sort of carried by the convictions of practitioners,” said James Serpell, a veterinarian at the University of Pennsylvania School of Veterinary Medicine, according to The Washington Post. “That kind of thing has almost driven the field, and the research is playing catch-up. In other words, people are recognizing that anecdote isn’t enough.”

According to Crossman, the evidence is problematic, because most studies had small sample sizes, and an “alarming number” didn’t control for other possible factors that might have changed stress level, like an interaction with the animal’s human handler. She also noted that studies also tend to generalize animals. For instance, if a person is measurably soothed by a golden retriever, that doesn’t mean that another dog –or animal will cause the same effect.

Hal Herzog, a Western Carolina University psychologist, believes that studies sometimes are taken out of context to support the practices. He recalled a 2015 study on the health benefits of having a pet dog, which NBC reported as “Here’s a reason to get a puppy. Kids with pets have less anxiety.”

Image credit: One World Play Project
Image credit: One World Play Project

However, while that study did find that children with dogs had less anxiety based on screening scores than children without dogs, the authors warned that their study did not answer whether dogs have direct effects on children’s mental health or whether other factors associated with having a pet dog benefit their mental health. Herzog also noted that cherry-picked positive results are a problem, as he says occurs in promotional material from the Human-Animal Bond Research Initiative (HABRI).

“The number of papers I see that start out, ‘It is now well-established that there are health benefits from owning pets’ – that drives me crazy,” said Herzog, according to The Washington Post. “Yes, there’s literature that supports that. But there’s also literature that doesn’t find that.”

More and more studies are being funded to analyze effects of therapy animals

Many experts believe that more research is needed to assess the actual benefits of therapeutic animals. The research is growing because funding is increasing, from HABRI to a public-private partnership between the Waltham Centre for Pet Nutrition and the National Institutes of Health. Crossman’s latest study at the Yale Innovative Interactions Lab was among the research being supported.

Her research involved the Labrador retriever Pardner and seven other certified therapy dogs. Over the past year, the dogs were used at the university for 15-minute sessions with children who had finished two stressful tasks: spontaneously creating stories and telling them to complete strangers (the researchers), followed by resolving math problems.

The researchers assessed whether the kids, ages 10 to 13, would think their time with the dogs to be therapeutic or relaxing. The study was designed to avoid some of the mistakes that Crossman said she’d seen elsewhere, which is why some of the 78 participants only played with a fuzzy blanket –as tactile stimulation is known to reduce stress- and why other participants waited for the 15 minutes.

Study to be published expects to find how dogs can affect children’s stress

The children involved in the study had to answer questionnaires to assess their anxiety and mood before and after. Spit samples, to measure the “stress hormone” cortisol, were taken at three points of the research. At the end of the study, all the children got a “junior scientist” certificate and an open play session with the therapy dogs.

Crossman, who stressed she’s an animal lover, declined to reveal the findings of her study before they’re published. However, she noted that “hopefully” they will show that dogs can affect children’s stress levels.

“I say ‘hopefully’ not just because I think it works or hope it does, but because these programs are used so widely,” she said, according to The Washington Post. “Kids are already participating in this on a huge scale. Ideally, the order goes the other way around: We test the idea, and then we implement.”

Source: The Washington Post