Breed clubs are important to the hobby for several reasons. One of the primary reasons is in resolving disagreements over what characterizes a breed. Not all so-called "all-breed" kennel clubs accept all breeds, or recognize certain varieties of dogs as constituting a true breed. In this instance, a breed club may maintain its own registry of lineage while at the same time lobbying for the acceptance of its breed by one or more kennel clubs.
Other breed clubs are for owners of well-established breeds who merely enjoy interaction with fellow owners of similar dogs. These breed clubs leave the function of a registry to such major kennel clubs as the American Kennel Club, the United Kennel Club, The Kennel Club, and the like and exist more for social purposes, the dissemination of news about the breed, and in some instances the organization of single-breed shows.
The American Kennel Club (or AKC) is a registry of purebred dog pedigrees in the United States. The AKC registered just over 900,000 dogs in 2006, of which the largest numbers were for the labrador retriever (123,760) and Yorkshire Terrier (48,346). Beyond maintaining its pedigree registry, this kennel club also promotes events for purebred dogs, including the Westminster Kennel Club Dog Show, an annual event which predates the official forming of the AKC, and the AKC/Eukanuba National Championship.