I have a Buff Orpington who is about 20 weeks old. She was fine, healthy and suddenly started limping Sunday - her right leg. She was hopping like a bunny when she ran, but she still scratched around the yard and used that leg. Monday she was a bit worse, limping more but still eating, drinking, scratching. Tuesday she was getting worse, so I checked for bumblefoot, (nothing) checked for swelling, foreign objects, break, toe nails all there, etc. and she seemed fine. Separated her from the others, she is eating and drinking, poo looks ok. Today she is still worse (will check again for bumblefoot) and is now holding up her right foot. She still jumps on the low roost in her pen, but is wobbly. I am a chicken newbie and don't know what else to check for. Seems like it could be a bad sprain - we have a rooster who is just coming into maturity with the hens, so maybe he injured her? What else should I look for? She does not like to be separated from the others, but we put her in a small cage overnight to try to keep her more quiet. Any other suggestions? I hate it when my animals get sick - I feel so helpless. Also, she was vaccinated when she was purchased. Thank you very much!