There is much debate as to whether a Parti Yorkie is even a true Yorkshire terrier. I can’t prove that
the Parti line was not a result of breeding a Yorkie to another breed of dog, that is the responsibility
of AKC. What I can show is that there is a probably of this color occurring in the Yorkshire Terrier.

 How the breed was formed
                              Sue James,

Today's Yorkshire Terrier is very different from the early Yorkshire Terriers of the North of
England. There are varying accounts of the origins of this breed and its development. I have tried to
give the most accurate, and most widely agreed upon history of the Yorkshire Terrier assembled
from books and publications written be reliable and experienced fanciers of the breed in the UK.

Before 1750, most British people worked in agriculture. The onset of the Industrial Revolution
brought great changes to family life. In Yorkshire, small communities grew up around coal mines,
textile mills and factories. People were drawn to these areas to seek work from as far away as
Scotland. They brought with them a breed known as the Clydesdale Terrier, or Paisley Terrier.
These were primarily working dogs, much larger than today's Yorkies, and were used for catching
rats and other small mammals.

These terriers were inevitably crossed with other types of terrier, probably the English Black and
Tan Toy Terrier, and the Skye Terrier; it is also thought that at some stage the Maltese Terrier was
crossed with these breeds to help produce long coats. As the outline of the Maltese resembles that of
many of today's Yorkies, this is very likely. Unfortunately, no records in the form of Pedigrees exist
to confirm these crosses (possibly because of the poor level of literacy in these times), but a great
deal is known about the type of people who bred them, and there can be no doubt that early breeders
had a very clear idea of the type of dogs they were attempting to produce. We can see in today's
Yorkies how strongly the terrier temperament has been retained.

            Here is an excerpt from Yorkshire Terrier Club of America
                                               Joan Gordon

The facts concerning the origins of the Yorkshire Terrier are usually presented in modern books as
being unknown.  

According to many present-day writers Yorkshires were the result of a number of breeds being bred
together to produce the desired points.  How anyone could believe, or even imagine, these early
fanciers would have bred from a Dandie Dinmont, a breed with an uneven top line; a Maltese, a
totally white breed lacking any blue or tan markings or from a smooth coated Manchester Terrier
(originally a smooth coated Old English Terrier) is not being realistic.  The name Manchester was
not even given to this breed until a later day.  We can only guess this latter breed was named
because one of Huddersfield Ben's ancestors was a dog named Albert from Manchester.  

One of the troubles in getting the Yorkies origins correct is that each of the three breeds necessary to
arrive at the final breed of Yorkshire Terrier are now extinct.  

What is consistent in both of these articles is that no one can state with absolute proof the origin of
the Yorkshire Terrier. Now what is interesting is that in one article they felt that the Maltese Terrier
was breed into the line to help produce long coats. The other author said it was unrealistic to have
breed a Maltese Terrier into the line because that breed is totally white breed lacking any blue or
tan. Now if we look at the terriers that are believed to be the origin of the Yorkshire Terrier and the
Yorkshire Terrier as we know today it becomes apparent that there had to be something in the lines
to produce the long silky coats we see today and the fact that the Maltese terrier is white doesn’t hold
any water. Because of the fact that the genes that control coat texture and control color are separate
genes any experienced breeder could have used a Maltese Terrier to improve the coat quality and
not change the color of the coat. By doing this would have produced Yorkies that carried the
recessive genes for the white color seen in the Parti Yorkies.

This is just one possibility of how the genes responsible for the white color in Yorkies, was
introduced in the 1800s.
Precious Little Paws ®
Parti Article