Definition of Pedigree of the Dogs
Determining the ancestry of mixed breeds is a complex task even for the for dog connoisseurs, as they have more genetic changes than purebreds. For instance, two black mixed breed dogs might possess recessive genes resulting in a light coat and able to produce offspring completely different from their parents.
Beginning in 2007 genetic analysis of blood samples and buccal swabs became widely available to the public. Companies claim that their diagnostic test based on DNA is able to determine the breed mixture at the genetic level. Such tests still have limited coverage, as only a small number of hundreds of breeds have been through such verification. In addition, these tests do not measure the breed’s purity but only the genetic sequences, common to certain species. For mixed breeds, such test does not prove the purity of pedigree but only an indication that these dogs have some share of common ancestry with some pure breed dogs. The American Kennel Club (AKC) does not recognize the use of DNA tests to define breed.
Also most of the new breeds of dogs are able to be traced back to the underlying breed what complicates the process of their genetic differentiation.
For example, Labrador Retriever, Flat-Coated Retriever, Chesapeake Bay Retriever, and dogs with Newfoundland mix sharing their pedigree with St. John's water dog (breed from the Newfoundland island no longer occurs naturally).