A companion dog is one whose main job is to keep people company.[1] It is not necessary that companion dogs be trained to perform any specific task.[2] Their main service is to provide companionship. A dog trained to perform a task for a disabled handler is called a service dog.[2]
While most any family pet could be considered a companion, the best companion dogs have certain qualities. First, they must be suited for living indoors.[1] They should be calm and not aggressive around other people or animals. A dog should be compatible with a person's lifestyle and personality.[3] Large dogs may not be suitable for very young children. Older people are increasingly choosing smaller dogs.[4] Therapy dogs and emotional support dogs provide comfort to people with certain conditions. Often they belong to staff members of hospitals or institutions.[2] Some dogs are certified as companion dogs and are selected for certain qualities.