I found him laying on his side on the floor of our coop. He can't use his legs and his neck is very stiff. He's got his head leaning back on his back. I took him out and gave him some water (I had to hold it up to his beak). He drank a little. I put him in the shade with his sisters and brothers. His legs and wings are limp. Yesterday he was fine, running around and eating and drinking... Any suggestions???