Pet therapy is a guided interaction between an individual and a trained animal. It also involves the animal's handler. The purpose of pet therapy is to help a patient recover from or cope with a health problem or a mental disorder. Pet therapy is also called animal-assisted therapy. Dogs and cats are the animals most commonly used in pet therapy. However, fish, guinea pigs, horses, and other animals that meet screening criteria can be used. The type of animal chosen depends on the therapeutic goals of a patient's treatment plan. Pet therapy, however, is sometimes confused with animal-assisted activities. Pet therapy is a formal, structured set of encounters. These meetings are planned to help patients reach specific goals in their treatment or progress.