Thursday I had my 4 hens and 1 roo out free ranging after work and I noticed my roo walking real hard. He's 3yo and in his first year, protected his girls from a Fisher cat. So he's always had kind of a "bum knee" i call it. But the next day I got home real late and he wasn't roosted with the others. It's still pretty cold at night so i put him in my spare room in the house, figuring it'd help get him back on is feet but this morning I found him 3 feet from the door of the room just laying there. He's kind of limp with his wings and tail but he's pretty attentive. He's eating and drinking just fine and his poop, since I brought him in, seems to be normal. 2 of them had a kind of blue tint. Those were more solid. The rest have been runny. I lifted his tail to have a look at his bottom and it was very limp. It just fell when I dropped it but he had nothing unusual going on down there. He is 3 years old, not sure what he weighs. He a mix between a red and Americana. i feed "natures best organic layer pellet". Coop is big but not well ventilated. It has windows i open in warmer weather. Wood shavings for bedding, no light or heat cuz we live off grid so im constantly giving freash water in winter. No other chickens acting strangely. Pictures of my roo Luna any advice would be greatly appreciated.