Aw he's so cute. I really think you should keep the puppy - you bought him knowing the signs were there that it was a puppy mill. He's cute and luckily is healthy. I think your puppy will be between 5 and 6lbs full grown which is still very small. Lacy is 7lbs. The next yorkie I get, I would like to have a smaller one -somewhere between 3-5lbs, but Lacy is really a great size and I wouldn't trade her for anything! She is the best dog

I wouldn't be so fixated on size - he may even surprise you and stay as small as you hoped.
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~Magnifique Yorkies~
Purchasing from backyard breeders, pet shops, and puppymills perpetuates the suffering of other dogs.
Educate yourself and buy from reputable breeders or rescue.