border terrier, breed of hardy, medium-sized terrier developed in the Border districts of N England in the 18th and 19th cent. It stands about 12 in. (30 cm) high at the shoulder and weighs from 131/2 to 151/2 lb (6.1-6.9 kg). Its weather-resistant double coat is composed of a short, dense underlayer and a close-lying, very wiry topcoat. It may be red, grizzle and tan, blue and tan, or wheaten in color, occasionally with a small amount of white on the chest. The border terrier was bred to hunt and kill the large hill fox of its native Border districts and came to be used against a wide variety of vermin. Raised today chiefly as a pet, it is a relatively rare breed in the United States. See dog.

border collie, breed of medium-sized, sheepherding dog developed in the British Isles. It stands about 18 in. (45.7 cm) high at the shoulder and weighs from 30 to 45 lb (13.6-20.4 kg). Its double coat consists of a soft, fuzzy underlayer and a harsh, very dense, wavy or slightly curly topcoat of varying lengths. Its color is black with white around the neck and on the chest, face, feet, and tip of tail. Bred for many years exclusively to develop its herding instinct, the border collie is unsurpassed as a sheep dog and has been used with equal success for herding cattle, swine, and poultry. It is exhibited in the miscellaneous class at dog shows sanctioned by the American Kennel Club. See dog.

Border, the, region surrounding the boundary between England and Scotland. From the coast near Berwick along the Tweed River through the Cheviot Hills and on to Solway Firth, the narrow, rugged country is dotted with sites of battles between the Scots and the English. The wild country figures much in literature—in legend, in folklore, and particularly in the Border ballads.

Breed of long-haired sheepdog that has been used along the English-Scottish border for about 300 years. Usually black and white, it stands about 20 in. (50 cm) and weighs 30–50 lbs (14–23 kg). It is the most popular working sheepdog in the British Isles.

Learn more about border collie with a free trial on Britannica.com.