A chow chow is considered a full-bred dog if it has two colors of chow chow in its bloodline. However, if a chow chow is mixed with another breed, it is no longer considered a full bred chow chow. This is because the gene pool becomes diluted and the dog's characteristics may change. While some people may still consider a mixed-breed dog to be a "chow chow," that dog is not technically considered a purebred.