Hi, welcome to YorkieTalk, it sounds like you need to totally revamp your training. We have a member by the name of ScootieBootie, who is a training specialist and gives special rates to YT members. Here is her page,
http://www.yorkietalk.com/forums/mem...tiebootie.html, it might be worth it to totally retrain your dog, and understand all the principles involved. Whenever a dog is biting some serious retraining is necessary, but if done properly, you'll have a much more enjoyable pet.