breed of small yet rugged and agile herding dog once used to herd the miniature cattle, dwarf sheep, and small ponies of the Shetland Islands; coat is long, straight, and dense everywhere on the body except the face and lower legs; coat colors may be either black, sable, or blue merle, any of which may be marked with white or tan streaks; ears are large, round-tipped, and fold slightly forward at tip; tail is long, bushy, and hangs straight down; eyes are medium-sized, almond-shaped, and normally black, though blue eyes are sometimes found in dogs with blue merle coats; adult stands 13–16 in. (33–41 cm) tall at shoulders and weighs 14–16 lbs (6–7 kg); reserved with strangers but very loyal and affectionate with owner; often called apartment-sized collies because they look like small collies, to whom they are probably related, ,