I need some help with a sick chicken I have and I don't know how to treat her. I first noticed she was sick yesterday and she's been walking slow, I noticed that her abdomen feels very tight and swollen, she's keeping to herself a lot, and she's having green/yellow diarrhea which is clumping up in her feathers. This happens to one of my chickens once a year and it's always the same symptoms. Two of them have died before and they're usually sick for about 2-3 weeks before they finally die. I would greatly appreciate if someone could help me figure this out so I can possibly save her...Thank you.