I have a male, neutered yorkie who is almost three years old. He has been the only resident dog for almost a year, my older dog, a gentle giant pit bull died last year. I just got a little female yorkie and he does not seem to be bonding with her at all. He is big too, almost 11 lbs and she is 3 lbs. He plays very rough and in fact the other night nipped at her and she screamed. I do not know what to do. I had her spayed so she has been in her large crate until she heals but I am afriad that once she is up and ready to move around again that he may attack her. He is very territorial also with toys and bones, not his food though. Any suggestions for me? Am I going to have to keep them separated their whole lives? Should I take him to a professional trainer (he is spoiled)? Thank you all.