I personaly would not get a puppy under 3 lbs. A yorkie Pup can still be healthy at 2.4 lbs, however nothing under 2 lbs. anther thing to be weiry of is that tiner they are the easier it is for them to hurt themselves by jumping off of funiture, getting stepped on, or sat on.
liver shunts, Hypoglcemia are just A couple illnesses a tiny Yorkie and suffer from.
A yorkie could still put on weight up to at least 7-8 months until they reach adulthood.