American pit bull terriers and American bulldogs are both descended from the English bulldog. Nineteenth century dog breeders began crossbreeding efforts in an attempt to create a breed that combined the game terrier spirit with the strength of the bulldog. These crosses made their way to the United States with English immigrants, where they eventually diverged into different breeds based on their owners’ needs.
The American pit bull terrier head should be a formed like a wide, blunt wedge, with a muzzle slightly shorter than the length of the skull and a wide, well-developed lower jaw. The American bulldog has a broad head that drops off dramatically to a broad and thick muzzle. Two different head types exist in the American bulldog standard. The “bully type” American bulldog, also known as the “Johnson” type, has a muzzle between 25 and 35 percent of the overall length of the head. The “standard” or “Scott” type of bulldog is slightly longer. The Johnson type also has a more undershot bite than the Scott type. Because they are intended to be athletic dogs capable of herding livestock and catching feral hogs, neither the American pit bull terrier nor the American bulldog should have difficulty breathing due to muzzle shape.
Height and Body Type
The American pit bull terrier is medium-sized, standing from 17 to 21 inches at the top of the shoulders. The American bulldog is much taller, standing from 20 to 27 inches at the shoulder. Both dogs have deep chests with well-sprung ribs and moderate tuck-ups at the loin, although the United Kennel Club pit bull standard states that the chest should never be wider than deep. The American bulldog has two different types: the Johnson style American bulldog has a bulkier body with more muscle mass and heavier bones than that of the Scott type.
Coat Length and Type
Both the American pit bull terrier and the American bulldog have short coats. While the pit bull coat is stiff to the touch, the bulldog’s coat can range for soft to stiff in texture and is never to be more than an inch in length. There is no maximum coat length requirement in the American pit bull terrier standard. Both breeds fault a wavy coat, but the pit bull standard also states that curly or sparse coats must be faulted as well.
The breeds’ standards vary widely in terms of acceptable colors. The UKC American pit bull terrier standard accepts all coat colors and patterns with the exception of the merle pattern. The National Kennel Club American pit bull terrier standard is more restrictive, accepting most colors and patterns with the exceptions of shades of gray and blue coloration and the merle coat pattern. The UKC American bulldog standard also accepts most colors and patterns, but all colors must have a minimum of 10 percent white hairs in their coats. The American Bulldog Association color standard is similar, although it requires a minimum of 15 percent white hairs to appear in a dog’s coat.
Temperament and Personality
The American pit bull terrier is expected to have some dog-related aggression, due to the breed's historical purpose. However, lack of aggression toward humans is characteristic of the breed, which makes the breed a poor choice as a guard dog. American pit bull terriers are known for their affection for children and their willingness to please their owners. The American bulldog is supposed to be a fearless dog, without viciousness or cowardice. Unlike the pit bull, the bulldog is an excellent watchdog and may be standoffish to strangers, particularly when the dog is an adolescent.