I thought I'd chime in about the tail - my purebred Clark didn't have his tail docked and it looks the same.
My other dog, Maple is only 70% yorkie (as per the DNA test) and we were surprised because she looks so different than a yorkie. Some similarities of course, but a lot of differences. Same tail though, too, lol. But just from looking I'd say your pup is 100%, but if you are really curious, DNA tests are pretty cheap now.
__________________ shaymic along with: Clark, pure yorkie puppy sweetness and Maple, 70% yorkie, 100% adorable |