Service animals are legally defined by the American’s with Disabilities Act (1990) and are trained to meet the disability-related needs of their handlers. Federal laws protect the rights of individual’s with disabilities to be accompanied by their service animals in public places.
Federal law does not legally define therapy animals, but some states have laws defining therapy animals. They provide people with contact to animals, but are not limited to working with people who have disabilities. They are usually the personal pets of their handlers, and work with their handlers to provide services to others. Federal laws have no provisions for people to be accompanied by therapy animals in places of public accommodation that have “no pets” policies. Therapy animals usually are not service animals.
Companion animal is not legally defined, but is accepted as another term for pet. “Social/therapy” animals likewise have no legal definition. They often are animals that did not complete service animal or service dog training due to health, disposition, trainability, or other factors, and are made available as pets for people who have disabilities. These animals might or might not meet the definition of service animals.