My one-year-old really sweet RIR rooster is sick. Yesterday morning my mother noticed him moving slowly and sitting with his feathers a little puffed up, I thought it was just because of the random cold snap (my roosters a big baby he always has been) by the evening he was acting fine. Cut to this morning and we let them all out to free range while we do some yard work but after about an hour he went into the coop and was just sitting on a mound of dirt. I gave him some Nutridrench water and an egg and he moved a little and went back out with the hens and fell asleep in a bush. He pooped while he was sitting there and it was really yellow and almost completely water. I don’t have any pictures right now but I’ll try to upload some later. We’ve already isolated him in a small coop in a cool spot with some water and food but we don’t know what’s going on or how to make him better. Any tips?