[LullaBelle]

Welcome to YT You will find a wealth of knowledge here.
I am sorry to hear about your problems with your baby. I hope that you will find out soon for both your sakes. My prayers are with you and you yorkie.
One thing I have learned from YT is that there is no such thing as a tea cup yorkie. That is a term used by "some breeders" so they can add to the price of the dog. I mean no disrespect to you or your breeder but its the truth.
That being said I have to wonder if your breeder knew something that they never told you? Like a hereditary allergy or something of the likes. I am not a vet nor do I claim to be but I just thought I should ask just in case. Its not unheard of, for a breeder to know of a genetic problem or a hereditary issue and not speak up about it. For you sake I sincerely hope that it is just a what if type of question but it is one I would ask.
If you don't know the pedigree of your baby I would find out just to satisfy your curiosity, so that way you know that area of your baby's health is clean.
Like I said I am not a vet but it is a question that I personally would ask and try to find out about. I hope you baby feels better soon!