Pets make us happy, as we all know. A growing body of research shows that pets can make us healthier.

This helps explain the growing use of animals, mainly dogs, cats, fish, birds, and even horses, in places ranging from schools and nursing homes to jails, mental institutions, and hospitals.

Take Vi, or Vi as it is commonly known. The retired guide is now the resident dog at the Children’s Inn, located on the National Institutes of Health Bethesda campus in Maryland. Families stay at the inn when their children undergo experimental therapies at NIH.

Vi, an oversized yellow Labrador Retriever with a tail that is always wagging, welcomes families when they arrive downstairs in the morning and also when they return to treatment in the late afternoon. You can “check her out” to stroll around the idyllic NIH grounds.

There isn’t one day that she doesn’t lift the kids’ spirits at the inn. “And an adult.” “And a member of staff,” says Meredith Daly.

Vi is doing much more than bringing smiles to the faces of parents and kids who are stressed out. Over the last 30 years, dogs like Vi have launched a new field of research.

Aubrey Fine is a California State Polytechnic University clinical psychologist and professor. She says that using pets as medical aids dates back over 150 years. Fine, a clinical psychologist and professor at California State Polytechnic University, says that Florence Nightingale recognized the importance of animals in providing social support to the mentally ill.

It was in the late 1970s, however, that scientists began to understand the scientific basis for this bond.

In 1980, one of the first studies found that patients with heart attacks who had pets lived longer. Another study showed that petting your dog can reduce blood pressure.

According to Rebecca Johnson, a nurse at the University of Missouri College of Veterinary Medicine who is the head of the Research Center for Human/Animal Interaction, recent studies have focused on the fact interacting with animals increases people’s hormone oxytocin.

Johnson: “That’s very good for us.” Oxytocin makes us happy and confident. Johnson believes this may be a way for humans to bond with their pets over time.

Johnson believes it could also benefit human health in the long term. Oxytocin is a powerful substance that can help the body heal and grow new cells. It also creates an environment where people are healthier.

Animals can act as therapists or facilitate therapy, even if they are not cats or dogs.

In his practice, psychologist Fine works with troubled children. He also uses cockatoos and a bearded Dragon named Tweedle.

He says, “one of the things we’ve always known is that animals can help a clinician get under the radar in a child’s mind, as the child feels more comfortable and is more willing to divulge.”

People with disabilities are also increasingly using horses as a form of therapy.

“The beauty of the horse is that it can be therapeutic in so many different ways,” says Breeanna Bornhorst, executive director of the Northern Virginia Therapeutic Riding Program in Clifton, Va. “Some of our riders might benefit from the connection and the relationship-building with the horse and their environment. Some riders may benefit from physical movements and will build core strength, body awareness, and muscle memory.

One of the instructors in the therapeutic riding program, speech therapist Cathy Coleman, worked with Ryan Shank Rowe, a 9-year-old boy with autism, on a recent afternoon.

It’s not one-on-one. Happy, a pony with speckles, was the co-therapist for this session.

Happy obeyed Ryan’s command to “walk on.” Coleman responded, “Excellent.”

Ryan answered Coleman’s question and kept up a constant back-and-forth chatter as the session progressed. He even made Happy trots and weaved between poles.

Coleman recalls Ryan being in a formal environment. Since he began horseback riding, however, his speech has improved.

She says, “I see greater engagement, alertness, language, and processing.” “Plus, it’s not just that he is good at this.

Donna Shank says that Ryan’s speech has improved because of the riding.

It’s helped him follow directions and some core life skills like getting dressed and balancing, which also translates into many other safety issues.

Not all research focuses on humans. Johnson of the University of Missouri says, “We are interested in how animals benefit from this exchange.”

Johnson has studied the benefits of dog walking by observing volunteers at animal shelters. She wrote a book called Lose a Pound by Walking a Hound.

She says that these programs have helped people become healthier. They increase their activity while walking their dogs. “But it increases their awareness so that they exercise even more during the week.”

The program also helped the dogs.

She says the extra exercise and socialization the dogs received in the group made them more likely to adopt.

Johnson is working on a project that will benefit both dogs and humans. Veterans returning from Iraq or Afghanistan provide basic obedience training to shelter dogs.

While it is still early in the research process, one thing is clear: “Helping animals helps veterans readjust to living at home.”

Research is now receiving a scientific boost.

With funding from the pet food giant Mars Inc., the National Institutes of Health recently created a federal program for studying human-animal interactions. The National Institute for Child Health and Human Development administers the program. It offers grants to scientists to investigate the impact of animals on child development and physical and psychological therapy treatments.

Johnson says it is essential to provide the scientific basis for the idea that animals benefit humans, even if this seems obvious.

She says, “The last thing that we want is an entire field based on warm-fuzzy feelings and not scientific data.” “It’s important that the NIH is focusing on this… it helps scientists like me to be able do our research.”