The Smooth Collie is a breed of dog developed originally for herding. It is a short-coated version of the Rough Collie of Lassie fame. Some breed organisations consider the smooth-coat and rough-coat dogs to be variations of the same breed. The Smooth Collie is a medium-large dog, ranging in size from 20–22 inches (51–56 cm) for females and 22–24 inches (56–61 cm) for males at the shoulder; weights vary from 40 lb (18 kg) for females up to 66 lb (30 kg) for males. Standard size for the breed is in the United States and Canada 22–24 inches (56–61 cm) for females and 24–26 inches (61–66 cm) for males at the shoulder; for example, for the AKC, the range is 22–26 inches (56–66 cm) and 50–75 lb (23–34 kg). (Source: Wikipedia.org, CC BY-SA)