One of my roos is sick and I don't know what's going on with him. Yesterday, my son took treats out and realized the roo, Willow, was the only one not participating, but instead was laying in the coop. He picked him up and noticed he had fowl mites. He also had a limp. I felt around his legs and couldn't identify any injury. His feet were fine, too. We gave him a permethrin solution dip and cleaned his bum where he'd been laying in his poop. No other chickens had mites, so I suspect he's just not been cleaning himself. Today he was still laying in the coop at treat time, but now his wings are splayed out and his brother has done a number on his comb. We removed him because his brother wouldn't stop attacking him. He's the only one sick in a flock of 19. I would spare him the misery and just process him because he's a right jerk, but I'm not keen on eating a mysteriously ill chicken. Any suggestions? Things to check?