This issue comes up a lot. I just replied to a similar post. I learned through vets, show breeders and online research, that Yorkie teeth may take longer to develop than other breeds. Some yorkies maintain their baby teeth through 7 -8 months of age. Some vets use general development/maturity principles to determine that your baby is younger than you were lead to believe.
There are unscrupulous 'breeders' who may say a pup is older so that you believe its done growing. HOWEVER, that's not always the case. A yorkie may legitimately be 6-7-8 months of age and still retain baby teeth.
Not all vets understand the development of the yorkshire terrier breed.
Good luck.
Tracey |