Assistance dog

An assistance dog is a dog trained to help a person with a disability in daily life. Many are trained by a specific organization, while others are trained by their handler (sometimes with the help of a professional trainer). They are not to be confused with therapy dogs.

Classification
There are three general "types" in which an assistance dog may be further classified. Most assistance dogs will be trained for only one of these, though "combination" dogs do exist.
 * Guide dogs assist the blind and the visually impaired.
 * Hearing dogs, or signal dogs, help the deaf and hard of hearing.
 * Service dog is a term covering dogs not specifically for visual or hearing impairment, such as mobility assistance dogs, seizure response dogs, and psychiatric service dogs. In the United States, the term "service dog" may be used synonymously with "assistance dog," and is occasionally used for other types of working dogs as well.

Accessibility
In many areas of the world, assistance dogs are not required to have any sort of "certification" or proof of their training; however, most programs voluntarily certify their dogs, and many wear a harness or cape to identify them. In the United States, where animals are banned from certain locations, the Americans with Disabilities Act of 1990 protects the rights of disabled individuals to be accompanied by their assistance dogs or other service animals in places the public is invited. Many state laws also offer similar protection and/or further guidelines. The United Kingdom has a similar arrangement.