Welcome to YT! I am no where near as educated on Yorkies and nutrition as some here, but maybe it is her food? What are you feeding her now, or has it changed recently? or has her stress levels changed any? I know when I am stressed I loose hair!
Just some thoughts.
Lisa
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My cute little Turbo butt!
YES, we are also avid members of the
CRAZYCLUB & Little Gentleman's Club! Turbo 
's Tumi!!!