Do Therapy Animals Help? Not Really | Science Codex:
"Therapy animals are on trend, everyone is getting some sort of certification so they can take their pets on the plane and into restaurants, but though no one in business wants to mess with mental illness, there is not much evidence they are more than placebo.
Instead of being able to show they really do much to help, a review showed some positive short-term effects, most often found no effect and occasionally identified higher rates of distress.
...“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.”
Like homeopathy, this has survived hundreds of years despite no evidence it works.
Like a lot of woo, such as eating placentas and environmentalism, this had a resurgence in the "natural" movement of the 1960s."