We are new to raising chickens. We have 6 hens and 1 rooster. All have been really healthy,good layers with no problems. One hen though, I have noticed a couple of days ago started getting poo in her feathers. Thought maybe just having a bad day. Today I have noticed something is definitely not right. The feathers all around her legs and tummy are now getting greasy looking and she looks like she is having spasms back there. One brown layer is not laying and I am assuming that it's her. If you can offer any suggestions and help me know what to try I will really appreciate it very much. I have really become attached to my little feathered friends and don't want any to be sick or suffer needlessly. Thank-you in advance for your help.