Skip to Content

Support MinnPost

UCare generously supports MinnPost’s Second Opinion coverage; learn why.

The belief that animal therapy helps reduce stress is based on problematic research

Belief that animal therapy helps reduce stress is based on problematic research
REUTERS/Susana Vera
Although animal-assisted therapy has been researched since at least the 1970s, the evidence to date does not offer a ringing support of the effectiveness of the practice.

Therapy animals seem to be everywhere these days — in hospitals, nursing homes, college campuses, prisons, corporate offices, libraries and even at the sites of natural disasters.

The reason: a widespread belief that interacting with animals reduces psychological stress.

And it’s not only interactions with therapy dogs. Horses, cats, rabbits, goats, hedgehogs, pigs, parrots and even, yes, ducks, are among the long list of animals now used in both individual and group therapy programs.

Yet, although animal-assisted therapy has been researched since at least the 1970s, the evidence to date does not offer a ringing support of the effectiveness of the practice. That’s because studies on the subject have been problematic, with many methodological limitations.

“Research findings in support of [animal-assisted therapy] has not kept pace with the widespread prevalence in practice,” writes Molly Crossman, a Yale University doctoral student in psychology who recently published a long review of that research in the Journal of Clinical Psychology.

At best, the evidence suggests “a small-to-medium effect on distress, but does not clarify whether animals account for the treatment effects,” she writes.

A promising method

Animal-assisted therapy is certainly a promising method of reducing distress, particularly on a large scale. As Crossman points out, it’s very accessible — the animals are brought to locations where people already are. It’s also much more efficient that traditional one-on-one approaches to treatment. One program, for example, served 417 university students during six 90-minute sessions — or an average of 46 students per hour.

Animal-assisted therapy also has the advantage of being perceived by the public as being effective at reducing distress. And it doesn’t carry the social stigma some people ascribe to traditional one-on-one therapy.

Yet despite these auspicious features, the research on the effectiveness of animal-assisted therapy has been problematic, says Crossman. For example, most of the studies have involved small numbers of people and have focused on the short-term effects on distress. They haven’t looked at whether this type of therapy has any long-term benefits.

Other problems with existing studies include generalizing across animals — the assumption that a patient’s positive interaction with one animal would be repeated in subsequent interactions with others.

And then there’s this inconvenient point: Many of the studies have found that  animal-assisted therapy has no effect on distress. “In a nutshell, some studies support the influence of [animal assisted therapy] on distress, but the overall state of the evidence is far from clear,” writes Crossman.

Concerns and controversies

A major concern regarding the existing research that has found a positive association between animal-assisted therapy and mood is this: Are the effects related to interaction with the animals or with the animals’ handlers?

Or, as Crossman asks: “Would any engaging and rewarding activity convey the same benefits?

That research needs to be done, she says, although such studies would be difficult to construct because of issues of ethics and safety. One possible solution would be to conduct the studies with the participants’ own companion animals rather than with ones brought by handlers.

Crossman also raises the highly controversial issue of emotional support animals — animals that are permitted to be in most public places because they have been deemed by a psychologist to be essential for that person’s wellbeing. (Emotional support animals should not be confused with working service dogs, which assist people who have physical or psychiatric disabilities.) 

As Crossman points out, there is considerable fraud regarding the designation of emotional support animals.

“Some healthcare providers will provide a prescription for an emotional support animal for a small fee,” she explains, “and fraudulent letters claiming that an animal is a specialized emotional support animal are readily available on the Internet.”

More rigorous research on animal-assisted therapy, Crossman points out, would help establish evidence-based standards for determining which patients would actually benefit from the effects of emotional support animals.

For more information: You’ll find an abstract of the review on the Journal of Clinical Psychology’s website, but the full article is behind a paywall.

Get MinnPost's top stories in your inbox

Related Tags:

About the Author:

Comments (3)

Almost every therapy lacks solid evidence

There's always been a disconnect between psychotherapy and research or evidence. The memory recovery therapy's of the late 80s and early 90s were a particularly egregious example. I don't know why anyone would expect these therapy/pet/animal claims to be any different?

The fact that animals and pets can offer companionship, comfort, an opportunity to develop a external relationships, and improve quality of life for some people is undeniable. But it's like any therapy from primal screams to EMDR as long as it doesn't hurt anyone, and as long as some people report feeling better, S'all good.

Pets aren't for everyone, but they do bring joy and pleasure to millions of people, so like any therapeutic intervention a pet can be beneficial to some and not to others, I can tell you that without doing a minutes worth of research... I've seen it, haven't you?

I used to work in a residential facility for mentally ill adults the early part of my career in psychology. At that facility I knew the most paranoid person I've ever met. On a typical day this guy was more paranoid than the most paranoid person I would ever come across later on in secure psychiatric units. The ONLY living thing that this guy was NEVER afraid of in the house was the cat or the dog whom he loved caring for. People who wouldn't come out of their rooms all day would take turns feeding, and playing with the cat and walking the dog. We never claimed it was therapy, but we all noticed it.

This business of putting a vest on a dog so you can get them on the airplane isn't about therapy, and parents who buy their kids pets because they think it will improve their kids IQ or social skills is just another example of silly parenting. I can tell you what the "research" will find- it will find that pets are helpful to some kids, not others, and even detrimental to some. Where's my grant money?

Re: Almost every therapy lacks solid evidence

Bravo, Mr. Udstrand. You earned my vote for a grant. Also thanks Ms. Perry and Ms. Crossman for the run down on Americans' creeping (and pretty creepy) emotional neglect. Finally somebody calls out fraudulent claims for what they are.

Last October

A friend gave me a pumpkin with an appealing light green color and a pleasantly smooth and folded skin. I did not carve it for Halloween, but instead adopted it as my companion vegetable. What I enjoyed most was embarrassing my children by carrying it with me on errands (and that indeed was my sole initial purpose), but I found that having it on the passenger seat next to me, and massaging it, did greatly calm me against the constant assault of oblivious and incompetent fellow motorists and ill-coordinated traffic lights.

Finally, just six weeks ago, my companion vegetable began to rot. In accord with my Zoroastrian preference for the ultimate disposition of my own carcass, I placed it on a rock in the sun and have respectfully observed its reintegration into the energy of the universe, which is nearly complete. I miss my companion vegetable but know that one day our spirits will be reunited.