I've visited lots of zoos, but I never ran into one of these! Fainting goats are a domestic breed of goat with a genetic trait that causes them to stiffen, and often fall over, when they are startled or excited. It's not a disease, just an inherited condition. They are also know as Tennessee goats, nervous goats, and by other names. The technical name for their condition is myotonia congenita. At first I felt sorry for them, but their strange trait actually endears them to people and there are associations of people who raise them. The best movie I've found in QuickTime format: link A descriptive site with some history, facts, and photos.