Your boy is adorable and looks all yorkie to me too!!

Don't let the vet's comment get you down. I am sure he did not mean to offend you, he just isn't very knowledgeable about yorkies. Someone once asked me if Nikko was mixed because of his coat. He has a very thick, wavy, cotton coat and this person said she had never seen a yorkie with hair like that. I started to get offended but in the end, it's not really offensive. She just didn't know. Before I came to YT, there was a lot I didn't know either. So don't take it to heart. You know you have a beautiful, loveable little boy who brings you lots of joy. Isn't that the most important thing?