I have exactly the same problem. Two weeks ago I got a female yorkie, 2 months old and brought her home to our male yorkie(2 years old). At first he did not want to even be near her. Now is still not better. If he is playing with a toy or a treat in his mouth and the puppy approaches him, he will drop whatever he has to escaped the puppy. He avoids her all the time. She wants so badly to play with him, be he doesn't, he runs away or growls at her. He always sleeps with my daughter, well now, he rather sleeps alone than in the same room with the puppy. How long will this last? The boy seems so sad and stress. But we cannot get rid of the puppy, we also love her. He is neutered. Thanks for any help