Males stand as tall as 22 inches and weigh up to about 45 pounds (20 kilograms). Females stand as tall as 21 inches and weigh up to about 42 pounds (19 kilograms).

They look like a lighter-weight Australian shepherd, but instead of the bobtail characteristic of the Aussie, border collies have a feathered tail that reaches to the hocks. The head is like that of a collie, and the body is slightly longer than the dog is tall. The ears stand but the tips drop over, giving them a jaunty appearance.

Some border collies have a coarse coat about three inches long, while others have a sleek coat about one inch long. A variety of colors are seen including black and white, red and white, black and gray, all black and tri-color. The longer-haired border collie usually has a lush mane and tail.

Border collies are active, working dogs best suited to country living. If confined without activity and company, these dogs can become unhappy and destructive. The breed is highly intelligent, learns quickly and responds well to praise.

Because of their herding instincts, they are protective of their family and territory and make excellent watchdogs. They will look out for the family kids. Although they get along well with children and other pets they are raised with, they can be reserved and sometimes snappish with strangers, nipping at the heels the same way they would nip at sheep if herding.

Border collies are extremely energetic dogs and must have the opportunity to get lots of exercise. They love to run. They also need ample attention from their owners and a job to do, whether that be herding livestock or fetching a ball.

They should be socialized well from the time they are young to prevent shyness around strangers, and they should have obedience training, which can help deter nipping behavior and a tendency to run off or chase cars.

Border collies are considered average shedders. Brushing at least weekly is needed to keep the coat nice. This breed lives about 12 to 15 years.

Border collies are herders and were bred to work sheep, but they can manage just about any type of herd and will even herd children in the family.

The breed originated in the lowland and border counties of England and Scotland and may date back to the 1700s. The ancestors of the border collie are thought to be other types of collies, such as the bearded collie and Scotch collie, and some breed historians believe spaniel might be in the mix somewhere.

During the 19th century, border collies became popular among English gentry. Today, they are still used for working livestock and are family pets. Because they train easily, border collies are also used for police work, narcotics and bomb detection and for search and rescue missions. They also make good guide dogs for the blind. Borders have recently entered AKC show rings amid controversy and protests from fanciers who worry breeding for appearance may compromise working ability.