American Pit Bull Terriers and American Staffordshire Terriers are closely related breeds, tracing their roots to the same founding stock. Few physical traits differ between APBTs and ASTs, and the primary differences relate to ancestry and naming conventions employed by breeders and registry organizations. While the differences between the breeds are slight, most professional breeders eschew mixing the gene pools, and treat the two lineages as distinct.
During the 1800s, European breeders began pairing bulldogs with terriers, in hopes of producing animals with the best traits of both parents. Ideally, the breeders hoped, they could produce dogs with the athletic prowess of bulldogs and the "gameness" of terriers. By the end of the 19th century, they had established just such a new breed, which went by several names, such as half-and-half dogs, pit bulls and Yankee terriers. Eventually, these dogs made their way across the Atlantic, as they traveled alongside their owners who immigrated to North America. Over the following years and decades, this new breed was used for a variety of purposes, including companionship, herding and fighting other dogs in small rings, called "pits."
As time went on, breeders began refining this founding lineage in a variety of ways. Some sought to produce dogs that excelled in the pit, while others strove to produce unique-looking lineages; still others emphasized traits that served their own particular purposes. In 1898, the United Kennel Club began recognizing one of these lineages as American Pit Bull Terriers, and they remain the only registration organization to recognize the breed. Another lineage became slightly heavier than the founding British stock, and in 1936, attained recognition by the American Kennel Club, which originally christened the dogs Staffordshire Terriers, before eventually changing the name to American Staffordshire Terriers.
Nose color is one of the most obvious differences between the two breeds. The AKC considers red noses -- a liver color -- a fault, preferring the either black or the so-called "blue" or slate-grey noses, while the UKC allows noses of any color. Accordingly, AST breeders have largely culled the genes that produce red noses from their bloodlines, while the same genes remain somewhat common in APBT lineages.
Additionally, ASTs are often slightly stockier than APBTs, weighing as much as 75 or 80 pounds, compared to APBTs, which seldom exceed 60 pounds in weight. The heads of ASTs are also more massive than those of APBTs.
Both breeds are strong, muscular and solidly built. They exude athleticism and confidence, especially for breeds of such modest size. They love to put these abilities to work, and are often incredibly efficient diggers and capable of pulling heavy loads relative to their size. They are both typically friendly with people, but require strong socializing during their early life to ensure they play well with other dogs. Both breeds tend to live long lives of up to 14 years, although they may be at increased risk of developing heart disease, mange, and dysplasia of the elbows or hips.