We had 3 chicks in a quarantine pen in our back yard. While we were away today the bottom of the pen broke off and the 3 chickens escaped into the yard (without us knowing). When we got home we let our dog's outside (6 of them). After a few seconds we heard something scream. Of course we ran outside and the largest chicken had been attacked. It was laying on it's side with a dog above it. There was no blood, but it wouldn't move. We think she has an injury to her left leg. She won't stand, but uses her wing for balance when we pick her up and put her down. She will not eat or drink - I am assuming she is in shock. She is a 4 month old Brahma (very large). I gave her a baby aspirin and have put her by herself in the garage. What else should I do? When I feel her left leg it feels somewhat loose, but she lets me mess with it. Should I just cull her or wait and see if she gets better??? We've never had anything like this happen - it's very upsetting of course. Thank you.