I think OP is asking what to do about the bird, not necessarily the dog. The "kill the dog" replies are absurd. Im would try feeding the bird a variety of things to spark its interest in food, like pumpkin and other vegetables. Keep her warm and have fresh water nearby. Im sure she will be fine by herself for a while. Ive had birds separated from the flock to heal, and they seemed content. Good luck and keep us updated.