Ok, my brother just got a 5 month old Rotty. She's very sweet adnd friendly and was actually trying to play with Gizmo, however Gizmo was terrified and tries to nip at her. When he did it she barked at him and got in his face and I'm afraid she'll feel threatened and try and bite him. He's like this with big dogs since the pitbull attack. How do I socialise him and get him tostop nipping at bigs dogs. This Rotty is going to be around for a long time, and they need to get along.