I have a RIR hen that is almost 5 years old, and she started displaying these symptoms yesterday or possibly the day before: 1. Difficulty moving around coop. Stayed inside hen house. 2. Toes and legs look curled and are paralyzed (wings are fine--she supports herself on them). 3. Poop looks runny and yellowish, and has little pellets in it that are greenish-black. 4. Still seems alert and has no difficulty breathing. 5. Drinking lots but eating little. Offering layer ration, scratch, grapes, and mealworms. Also have added ACV to her water. I suspect my husband let the food get a bit moldy, but I'm not certain. This EXACT thing happened to another hen, another RIR that was shipped along with her when they were day-old chicks, last year or maybe the year before. My husband eventually put her down because she seemed to really be suffering. This one (Squanto) doesn't seem to be suffering--at least not yet. She actually seems quite content to stay in the cardboard box in our half bath! I keep thinking Marek's, but wouldn't that have presented years ago? I have never supplemented with vitamins or used antibiotics or anything with my hens. Should I? You can see in the pics that she spreads out her wings to support herself. The poop picture isn't that clear--sorry. I think you can see the weird pellets and gooey poop, though. I would surely appreciate any insight from you all! Thank you! Here are a few pictures: ETA: I wasn't able to get a picture of her legs and feet because I'm home alone with the kids, but I can take and add one this evening after husband or mom gets home if y'all think it would be helpful.