[3] Before this, no records were kept and instead of breeds, there were informal landrace strains that initially depended on where a dog's parent or master originated.

[5][6] Dogs had been used since the 13th century in bull-baiting, but the first known mention of bulldogs by name is not found until a seventeenth-century letter requesting them to be sent from London to St. Sebastian, Spain.

[11] This ban was not in effect in the United States; however bull-baiting lost popularity as a form of entertainment, contributing to the rarity of the dogs.

[15] In November 2019, the breed was added to the American Kennel Club (AKC) Foundation Stock Service (FSS).

[17] The American Bulldog is a stocky and heavily built dog with a large head and a muscular shoulders and forearms.

In general, American Bulldogs weigh between 27–54 kilograms (60–119 lb) and are 52–70 centimetres (20–28 in) at the withers,[15] but have been known to greatly exceed these dimensions, especially in the "out of standard" nonworking stock.

[18] The American Bulldog is predisposed to the following dermatological conditions: allergic skin disease, ichthyosis, solar dermatosis, and squamous cell carcinoma.

[19] A review of patient records in the US from over 600 hospitals found the American Bulldog to be predisposed to juvenile-onset demodicosis with a 3.4 odds ratio.