The problem I've heard regarding turkey: vets report that there is a spike in the number of cases of pancreatitis after Thanksgiving and Christmas, and that's in all breeds, not just Yorkies. It seems that people "sneak" table food to their dogs while they are eating. But, my understanding is that the culprit wasn't the turkey meat itself, but that nice, crispy skin. Yes, the dogs love it, it is tasty! But the rich, high-fat hit is especially hard for a smaller dog to handle.
Dogs, Holiday Foods, and Pancreatitis: Thanksgiving and Christmas Treats Can Make Your Dog Sick
It isn't the protein source, it is getting the high fat "treat" that is of concern. So roasted turkey breast, OK. Turkey skin, bad.