Pitbull

The Pitbull, with its distinctive stocky, muscular build, was originally bred to 'bait' bulls, giving them their name. Their role then evolved to all-around farm dogs, and later moved into the house to become 'nanny dogs' because they were so gentle around children. Nowadays, pitbulls are the most bred dog in America, and are also the most common in shelters and most euthanised.