From Wikipedia:

“Therapy Dog refers to a dog trained to provide affection and comfort to people in hospitals, retirement homes, nursing homes, mental institutions, schools, and stressful situations such as disaster areas.

The concept of a therapy dog is often attributed to Elaine Smith, an American who worked as a registered nurse for a time in England. Smith noticed how well patients responded to visits by a certain chaplain and his canine companion, a Golden Retriever. Upon returning to the United States in 1976, Smith started a program for training dogs to visit institutions. Over the years other health care professionals have noticed the therapeutic effect of animal companionship, such as relieving stress, lowering blood pressure, and raising spirits, and the demand for therapy dogs continues to grow. (more…)