Topic summary
Stud book
Extracted from the Wikipedia article Breed registry.
Closed stud book
A closed stud book is a stud book or breed registry that does not accept any outside blood. The registered animals and all subsequent offspring trace back to the foundation stock. This ensures that the animal is a purebred member of the breed. In horses, an example of a closed stud book is that of the Thoroughbred, with a stud book tracing to 1791. The American Kennel Club is an example of a kennel club with primarily closed books for dogs; it allows new breeds to develop under its Foundation Stock Service (FSS), but such dogs are not eligible for competition in AKC conformation shows, although they do compete at those shows in the FSS category. For the breed to move to the Miscellaneous class and then to fully recognized status, the breed's stud book must be closed.