Never seen a mini-horse that was trained as a seeing eye dog, they are used by people that need "emotional support" which falls into the mental illness category. If they were leading around a blind person then it would be a physical condition but anytime someone needs a mini-horse, ferret or any other animal for companionship that's a mental illness. Normal people don't need to have their pet to keep from having a panic attack, though I seriously doubt any of the con-artists running around with their mini-horses or other animals would really have a panic attack as they are just trying to game the system. It seems so funny that years ago you never heard about anyone needing a emotional support animal.. .now suddenly when airlines are forced to allow them everyone start popping up with a need for one.

Miniature Horses as Service Animals | What Can They Do?
Laws have changed to allow miniature horses as service animals. We cover their benefits, tasks they can perform, and how to obtain one.
