[yorkietalkjilly]

Yea, just separate them until Beau comes to gradually accept her. He could probably bite and scare her pretty bad should he get her in a tender place so I'd watch him like a hawk until he proves a good record of tolerance. Likely right now he feels it's his job to protect you and his territory from this 'invader'. Focusing intently on her with staring, wide eyes, ears up, alert, mouth and body tense, tail erect or straight out, maybe wagging slowly are good indicators he's about to pounce on her so watch him and stop that type of behavior the very instant you see the first sign by quickly saying 'uh oh', (save saying 'no' for after after he learns appropriate behavior but breaks the rules) standing up, staring at him and snapping your fingers as you point at him, walking quickly toward and into his space to back him down, staring and still pointing at him until he turns and leaves. At that moment, you instantly relax to show him that's all you wanted, him submitting to you, case closed. This will show him that you and not he, decides what pack behavior is acceptable and who gets accepted into your little family pack.

Quickly redirect him to another positive activity and don't forget to show him love and affection and favorite treats when he's once again behaving appropriately, but not so quickly after redirecting him that he conflates your affection with approval for his hostility toward the new baby. No doubt he'll need extra cuddle time, longer walks and play sessions with you to keep him feeling positive about the whole new-baby experience.

Keep close-encounters between the two short and sweet and closely monitored for the time being. Any time he is nice to her, instant praises and treats but stern backing him off if the very instant he shows a hint of aggression or hostility, then relaxing the moment he submits. He'll get the message and accept her over time. Dogs are pack animals and he'll grow to adore having one of his very own kind.