The black Russian terrier and the bouvier des Flandres bear a superficial resemblance to each other. In part, this resemblance is due to the manner in which the two breeds are groomed, with heavy eyebrow and mustache hairs accentuating their powerful heads and their double coats trimmed to accent the outlines of their bodies. Despite these superficial similarities, the black Russian terrier and the bouvier are quite different breeds.
The black Russian terrier is a member of the American Kennel Club's Working Group and the United Kennel Club's Guardian Group. The breed primarily serves as a guardian and a protection dog. By contrast, the bouvier is a member of both registries’ Herding groups. The bouvier des Flandres was developed to herd and to drive cattle. Now in less demand as a herder, the bouvier often serves as a guide dog and in police forces and armed forces. However, both standards of perfection require the breed to have a steady and resolute temperament without the aggression that's expected of the black Russian terrier.
Both the black Russian terrier and the bouvier de Flandres have short-coupled bodies with flat toplines. The black Russian terrier has triangular ears that are high-set and that lie close to the sides of the dog’s head. The breed’s muscular neck is set on the shoulders at a 45 degree angle. The black Russian terrier’s body has a moderate tuck-up, its outline rising noticeably from the ribs to the front of the rear legs. The bouvier has standing ears, sometimes cropped. The dog's neck is also muscular but is arched and is set upright at the dog’s shoulders. The Bouvier has only a slight tuck-up.
Both the bouvier des Flandres and the black Russian terrier have heavy double coats with thick undercoats. The outer coat of the black Russian terrier has a harsh and wiry “broken” texture similar to other terrier coats. While the bouvier also has a harsh coat, the dog's coat is rough and long, more like that of a collie, and has a tousled appearance. The black Russian terrier has only one accepted color, black, which may have scattered gray hairs. The bouvier may come in many colors, from fawn to black. The bouvier may also have a brindle coat pattern and a limited number of white hairs on the chest.
The black Russian terrier is unique among all breeds -- the dog was specifically bred to have an aggressive temperament by a Soviet government-operated kennel for use by the military, created by selectively breeding Rottweilers, giant schnauzers, Airedale terriers and a number of other breeds. The herding bouvier, in contrast, must not be aggressive to humans or animals. That makes the bouvier more suited as a family pet than the black Russian terrier.