American Staffordshire Terrier (American Pit Bull Terrier)

The American Staffordshire Terrier and the American Pit Bull Terrier (APBT) were bred from the same lineage, but received different names from the two American kennel clubs; Staffordshire was the name given by the American Kennel Club (AKC), and American Pit Bull Terrier by the United Kennel Club (UKC). When compared with the English Staffordshire Bull Terrier, the American Pit Bull Terrier is larger by margins of 6–8 inches (15–20 cm) in height and 25–35 pounds (11–16 kg) in weight.

The dog was bred first to bait bulls and bears. When bear-baiting and bull-baiting were deemed inhumane, rat-baiting and dog-baiting became more popular. The APBT Breed was used in both sports, and its prevalence in being put in pits with rats, or other dogs led to "pit" being added to its name.

The American Pit Bull is medium-sized, and has a short coat and smooth well-defined muscle structure. Its eyes are round to almond shaped, and its ears are small to medium in length, typically half prick or rose in carriage. The tail is slightly thick and tapers to a point. The coat is glossy, smooth, short, and stiff to the touch. The accepted coat color can vary widely, but, both the AKC and UKC do not recognize merle coloring. Color patterns that are typical in the breed are spotted, brindled, solid, and with points.

Twelve countries in Europe, as well as Australia, Canada, Ecuador, Malaysia, New Zealand, Puerto Rico, Singapore, and Venezuela have enacted some form of breed-specific legislation on pit bull-type dogs, including American Pit Bull Terriers, ranging from outright bans to restrictions and conditions on ownership. The state of New South Wales in Australia places restrictions on the breed, including mandatory sterilization. The breed is banned in the United Kingdom, the Canadian province of Ontario, and a few counties and cities in the United States.