How do humans and animals interact with each other in the world?

Those of us who own pets know they make us happy. But a growing body of scientific research is showing that our pets can also make us healthy, or healthier.

That helps explain the increasing use of animals — dogs and cats mostly, but also birds, fish and even horses — in settings ranging from hospitals and nursing homes to schools, jails and mental institutions.

Take Viola, or Vi for short. The retired guide dog is the resident canine at the Children's Inn on the campus of the National Institutes of Health in Bethesda, Md. The inn is where families stay when their children are undergoing experimental therapies at NIH.

Vi, a chunky yellow Labrador retriever with a perpetually wagging tail, greets families as they come downstairs in the morning and as they return from treatment in the afternoon. She can even be "checked out" for a walk around the bucolic NIH grounds.

Thelma Balmaceda, age, 4, pets Viola, the resident canine at the Children's Inn on the campus of the National Institutes of Health in Bethesda, Md. Families stay at the inn when their children are undergoing experimental therapies at NIH.

"There really isn't a day when she doesn't brighten the spirits of a kid at the inn. And an adult. And a staff member," says Meredith Daly, the inn's spokeswoman.

But Vi may well be doing more than just bringing smiles to the faces of stressed-out parents and children. Dogs like Vi have helped launch an entirely new field of medical research over the past three decades or so.

The use of pets in medical settings actually dates back more than 150 years, says Aubrey Fine, a clinical psychologist and professor at California State Polytechnic University. "One could even look at Florence Nightingale recognizing that animals provided a level of social support in the institutional care of the mentally ill," says Fine, who has written several books on the human-animal bond

for example humans and animals interactw ith each other for example when humans have pets, they interact with commands and the humans assist them.

Explanation:

because a dogs obey their ownsers