Heard of a guide-horse for the blind?

I had never heard of a miniature horse in place of a guide dog. They live longer, are smarter, and are instinctually natural at reading the gestures of the person beside them. This article discusses the wide variety of animals being used, and the variety of ways that people are trying to abuse the practice just to allow them to take their animals with them everywhere.

http://www.nytimes.com/2009/01/04/magazine/04Creatures-t.html?pagewanted=1&_r=2&hp