"Pit Bull" is most often used incorrectly as a general term for dogs that have certain characteristics or type. More accurately, it's the shortened name for American Pit Bull Terrier. The American Pit Bull Terrier (APBT) is considered a purebred. "Pit Bulls" are registered by their formal names with kennel clubs as either "American Pit Bull Terriers" (UKC, ADBA) or as another breed, "American Staffordshire Terrier" (AKC), although there have been dogs registered as both. That alone shows that they are an existing pure breed, but so does their long history. Pedigrees, which are written family trees, go back 200 years or more for some of these dogs. They are an older breed than many.
The media commonly lumps three breeds together. While they may have all originated from similar dogs in Britain, they are separate breeds in their own right, such as Staffordshire Bull Terriers, which are smaller and look different, American Staffordshire Terriers, which have different bloodlines than APBTs, or Cane Corsos, a Mastiff-type dog that weighs around 100 pounds. Another similar breed is the American Bulldog. They look similar but they have a lineage and breed standard of their own. Many other breeds are related to Pit Bulls somewhere in their history, such as Boston Terriers, Boxers, and Bulldogs. Additionally, there are also mixes called the American Bully, some of whom look like oversized, stocky Pits with huge heads.
If you have adopted a Pit Bull or you are unsure of your dogs origins, he may be purebred or may be a mix. The way to identify what breed you have is to look at physical characteristics and compare them with the breed standard. For example, purebred Am Staffs have a black nose. But does it really matter? A dog is a dog, whether pedigreed or not.
Please spay or neuter- there is a crisis overpopulation of Pits due to over-breeding and they are being euthanized in shelters. Bad breeders and irresponsible owners have given this breed a bad rap. Don't be part of the problem, be part of the solution- neuter and train your dog.
Glossary:
Pit Bull: Term used to describe several breeds of dog in the molosser family, often mis-used by the media to describe a dog based on looks.
UKC: United Kennel Club (registry)
ADBA: American Dog Breeders Association (registry)
AKC: American Kennel Club (does not register Pit Bulls, but does register Am Staff)
Pedigree: A document to record ancestry, sometimes referred to as "papers"
Breed Standard: A set of guidelines developed to define the regulations and ideals for a certain breed, to which dogs can be evaluated