To most people, upon looking at Biewers and Parti Yorkies, one would associate them as being the exact same breed. In essence, they are. But there are significant differences. The Biewer is considered a separate breed from the Yorkshire Terrier, even though its bloodline is strictly related to the Yorkie. The Biewer was developed in Germany in 1984. It is pronouned BEE-VAH. Many breeders in America who admired and loved the beauty of the Biewer have imported them here to breed in their own breeding program. All Biewers' bloodlines go back to the original ancestors in Germany. They do have a specific color pattern and do not dock the tails. Biewers are not AKC registerable, their registry originates in Germany still to the best of my knowledge.
The Parti Yorkie was created here in America from AKC Yorkshire Terriers that carried the parti gene color. A breeder in California created the line by breeding more and more of the white recessive gene color together to eventually become what we see today, as being almost all white. The Parti Color Yorkie is 100% AKC Yorkshire Terrier and is now an accepted color on the AKC registrations. The parti color does not have a specific color pattern. Any yorkie that has significant white patches or coloration combined with black and gold is considered a parti color yorkie. The tails are docked by most breeders.
Although, some of the more conservative thinking breeders prefer not to associate the Parti Yorkie with the traditional colored Yorkshire Terrier, the color and quality of the Parti Yorkie grows in popularity and is very much accepted by AKC and its bloodline comes strictly from the Yorkshire Terrier, making them full blooded Yorkshire Terriers.
Both AKC parti colored yorkies*** and Biewers*** are recognized by YTCEHB and accepted into this organization.
***Please remember to look for these registries (above) and to stay clear of puppies that are CKC (Continental Kennel Club)