Every Wednesday night, Mike Massie drives his dog, Gio, to Inova Fairfax Hospital, where Gio is a minor celebrity.

A bandana tied on his neck, the golden retriever/Labrador mix makes the rounds visiting sick children. Sometimes he sits on a bed while a child strokes his ears; other times he picks up a penny or shakes hands. Each child gets a baseball card with Gio’s photo on it.

Massie and Gio have been visiting the hospital for two years with People Animals Love, a pet-therapy group based in the District. “It’s a fun distraction from the normal routine of shots and pills,” says Massie, a financial adviser with UBS Financial Services. “You give the child a moment of relaxation and relief.”

Pet-therapy organizations send volunteers with pets to nursing homes, hospitals, shelters, schools, and libraries. Most of the therapy pets are dogs, but many organizations welcome all kinds of animals.

Research shows that time with pets has health benefits. A study from the American Heart Association found that one 12-minute visit with a dog improved the heart and lung function in patients with heart failure. Other studies show that a short visit by a therapy dog can reduce agitation in people with Alzheimer’s.

Margie Weaver of the Citizens Care and Rehabilitation Center in Frederick says residents smile and perk up when four-legged visitors arrive from Wags for Hope, a Frederick pet-therapy group.

Gabe O’Neill, president of Wags for Hope, helped arrange for a horse to visit a man in an assisted-living facility in Frederick. When the horse arrived, the resident was waiting in a chair in the parking lot. “I broke into tears watching him pet the horse with a big smile on his face,” O’Neill says. “That is what animal therapy is all about.”

These organizations offer volunteer opportunities for people and their pets. Some require that animals pass a temperament test and go through training, some have registration fees, and some have age restrictions for the animals.

Fairfax Pets on Wheels, Fairfax; 703-324-5406; fpow.org.

National Capital Therapy Dogs, Highland; 301-585-6283; nctdinc.org.

People Animals Love, Northwest DC; 202-966-2171; peopleanimalslove.com.

Pets on Wheels of Prince George’s County, Brandywine; 301-853-3330; pgpetsonwheels.org.

Wags for Hope, Frederick; 240-782-4233; wagsforhope.org.

This article first appeared in the December 2008 issue of The Washingtonian. For more articles from that issue, click here.