A DNA Control Scheme links DNA testing to Kennel Club registrations by limiting registration to those dogs that meet the requirements of the breed-specific Control Scheme (i.e. dogs that are DNA tested normal or hereditary clear). These are put in place to eradicate a breed-specific disease that is severely affecting a breed. There are 4 levels of a Control Scheme, with gradual changes in the scheme at each level to meet the specific circumstances of a disease within a breed. The level at which a Control Scheme is set depends on the specific needs of the breed, but under most circumstances starts at Level 1, progressing to level 4 as the disease is gradually eliminated from the breed.