Horse is a common name for hoofed mammals that include the domestic horse and three groups of undomesticated species. One group is made up of the zebra, native to Africa; another consists of the ass, including the kiang and onager of Asia and the wild ass of Africa. The third group contains Przewalski’s wild horse, which is now found only in captivity. Horses belong to the equus family. Equus comes from the ancient Greek word meaning quickness. There are over 350 different breeds of horses and ponies. The horse was the last working animal to be domesticated.