BBC American Bulldog Standard.

Tall, stands erect with head held high, with back straight neither swayed or ridged. The tail should be held down approximately to the hocks, chest wide moderate and deep.
Broad, flat on top, squared appearance with muzzle short to medium in length, with a prominent dish between eyes. Lower jaw should protrude slightly more than the upper jaw, with wide apart eyes. Ears medium in size with a roll backwards or a flop.
Very friendly in daytime, but very aggressive at night, especially with the person not known. This dog should be eager, bold, and trusting with no signs of fear or timidity. Aggressive enough to fight a mean bear or wild hog, but gentle enough for a house pet.
White, to all brindle colors, with white to solid brindle, solid black, or black mixed with brindle or white.
Males from 22 inches to 32 inches and weighing from 70 LBS to over 100 pounds.
Females: from 18 inches to 28 inches and weighing from 50 to over 80 pounds.
Body structure should be big and rugged showing strength and endurance.

Showing Rules
Follow the above standards: Dogs must be untrimmed and unaltered. Tails are held down in a normal stance. Exception---Dogs may be showed if altered by a vet and a handler has a statement from the vet.

   It is hoped that the standards will help both the breeder and the show judge in the selection of the dogs that will better the breed and make dogs more enjoyable to their owners.
The American Bulldog was developed in early years for the purpose of catching and holding wild pigs and cattle. It was also used as a fighting dog that had no equal. The American Bulldog is still used in many places to work with pigs and cattle, but human laws and common sense has stopped most of the fighting of dogs. Today the American Bulldog is used for a family pet and a fearless guard dog. Old people and ladies living alone have made the American Bulldog the preferred family guard dog. It is said that anyone can sleep soundly with the knowledge that the family American Bulldog is on sentry duty all night.
From the beginning in southern farm communities the love of the American Bulldog has spread nation wide and to many other countries.