A collie or a collie dog is a dog with long hair and a long, narrow nose. Breed of working dog developed in Great Britain, probably by the 18th century. The rough-coated variety was originally used to guard and herd sheep; the smooth-coated variety was used to drive livestock to market. Both varieties are lithe dogs with a tapering head, almond-shaped eyes, and erect ears that tip forward at the ends. They stand 22-26 in. (56-66 cm) tall, weigh 50-75 lb (23-34 kg), and may be variously coloured. See also border collie