Miniature horses may be small--they're not much bigger than large dogs--but they are very strong. In fact, minis were once put to work pulling wagons in coal mines. Nowadays, miniature horses are kept as family pets, but they still help people in other ways. Some minis visit schools, community centers, and senior citizen centers to cheer people up. It's clear that these gentle creatures are no ordinary pets A miniature horse might be an unusual choice...