Psychiatric service dogs may be of any breed or size suitable for public work. The ADA regulations specify that only dogs, or in specific cases, miniature horses, may work as service animals. Many psychiatric service dogs are trained by the person who will become the handler—usually with the help of a professional trainer. Others are trained by assistance or service dog programs. Assistance dog organizations are increasingly recognizing the need for dogs to help individuals with psychiatric disabilities, and there are even organizations dedicated specifically to supporting psychiatric service dog handlers.