Both Partis and Biewers have what is called a recessive pie-bald gene that is responsible for their coloration. The Biewer breeders took what essentially was a Parti Yorkie and breed it many hundreds of times to develop a special coloration and marking for the dog. The Biewer has a standard and several clubs and is trying to get listed with the AKC registry as a separate breed. Because European countries have banned tail docking the Biewer standard calls for a full tail. Parti's on the other hand really have no official standard, and are just regular yorkies who have two recessive piebald genes, and their color is considered not within standard, but they are can still be listed with the AKC if their parents were listed. There is no separate category for Parti, that I'm aware of, they are just considered Yorkshire Terriers. |