It is unknown why herding dogs were originally called collies. This could be a corruption of a Gaelic word meaning "useful," theorises "Herding Dogs: Their Origins and Development in Britain." But no matter where the name originated from, dogs that helped shepherds were called collies. Two of the most popular types are the rough collie, also called the collie, and the border collie. Both breeds developed in the UK.
Collies, both rough and smooth-coated varieties, average 22.7 to 34 Kilogram and grow to be 22 to 26 inches high at the top of their shoulders, according to the American Kennel Club. In contrast, the border collie only grows between 18 and 23 inches high and weighs between 35 to 50 pounds, according to "The Howell Book of Dogs." Both male collies and border collies tend to be taller and heavier than females.
Collies come in several colours, with the most popular being sable and white, which was the colour of the popular fictional collie Lassie. Collies also come in white, which may have some small coloured markings; tricoloured with black mixed in the sable and a blue merle, with spots on a light blue background and white. However, all collies have a white bib marking around their necks and down their chests. In contrast, border collies come in far more colours and patterns. The most popular is black and white, but they also come in all black, brown and white, tricoloured, blue merle and white, sable and merle mixed, and mostly white with some black spots. Other unusual colours include brindle or black and orange striped; Oz Red, which is yellow and white, black with tan legs, belly and eyebrows; and lilac, a type of grey.
Collie ears are tulip-shaped, meaning their bases stick up but the tips flop down. Border collie ears can be this shaped or stick straight up or flop straight down. Collies have much longer, narrower noses than border collies. When collies stand in profile, their heads are wedge-shaped while border collie profiles look rounder and blunter at the muzzle.
Rough collies or "Lassie dogs" have long, thick coats that need daily brushing to avoid tangles. The white areas can be hard to keep white as collies like to get dirty. The smooth-coated variety of collie is much easier to groom, but this variety is rarer than the rough coat. In contrast, border collies do not need the intensive brushing and bathing that rough collies need. Border collies also have smooth and rough-coat varieties, but the rough coat does not grow as long or as thick as a rough collie's.