You never know...maybe your Yorkie Just needs some time.
I have a Shih Tzu I bought as a baby who was pretty darn bald and most shih tzu's are super fuzzy . She is just NOW starting to sprout some new hair growth.
I want to say I KNEW this about her though when I chose her. My Zoey had been VERY tiny and skinny when she was born. She was half sized and the breeder hand fed her for WEEKS. The breeder told me they totally expected she would not make it but they kept trying with her. All her littermates were full and flufffy . This poor baby was nothing but wisps of fluff and pink skin that you could see in the light, but very healthy and lively so i took her anyways because she had the CUTEST face
. Now months later I'm really glad because either way I would have still loved her to death....but just by luck she started sprouting new hairs lately
.
I'm so glad I went with my gut feelings because even though she is still a bit thin haired she has THE BEST temperment and really is very healthy despite her hard beginnings.