is it a broken leg? and what should i do?

[tallulah4]

My dog just busted through the fence and snatched up one of our 6 week old birds. She seemed really stunned for a while and we thought she was paralyzed, but now her eyes are open and she's moving around a bit, dragging one of her legs behind her. There are no open wounds. Should I assume the leg is broken? How do you know if it's the tendon? I isolated her from the other birds and have her safe inside. What should I do next? She's the friendliest chicken i've ever met - I feel awful!