My Rog, a horseperson, says if you use them a lot, esp. on pavement, their hooves will wear out too quickly, so shoes help to protect, BUT if you don't use them that much in that way, they are better left unshod. He says a barefoot horse will do better on ice than one with shoes, unless they are super-caulked (special shoes for ice). Shoes are also used sometimes for corrective reasons. When we lived on the prairie of Wyoming, we never put shoes on our horse.