I am so happy that your baby is very healthy! Let me start by saying I am typing this in a kind, gentle tone of voice...not "ATTACK!!!!!". I think that in general the tinier ones tend to be/get all or some the things mentioned above. Not every one. Just like all or some of the things can happen to a standard or even over-sized Yorkie. It is not meant to be an insult to any tiny little Yorkie regardless of health. I don't think my Cowboy will ever reach 3 pounds. Thank God he is healthy also. I do worry about him more though because his bone structure is just more delicate...little wee bones. Of course those will break easier than bigger bones. What irritates people is the exploiting of tinies and then NOT mentioning the greater health risks. A natural born runt is just that and there is absolutely nothing wrong with owning one.
People may be hesitating to add to this thread for fear of it turning nasty as it has so many times in the past about "breeding" for tinies.