Hey there, I have to admit I highly doubt that the hives have any connection to your yorkie. I have to say I'm highly allergic to cats and dogs that shed alot but with my yorkie I'm absolutely fine. They're hypoallergenic and don't shed at all, well I'm not sure if all of them are like that but with mine I have absolutely no problem. Just a little advice out of my experience. I'd definetly say to reassure yourself about where the allergy is coming from before giving your little furbaby away. Take care and fill us in on any updates