This morning when cleaning the poop tray I noticed some very watery poop, with blood in it. At least 2 spots. When I let the chickens out to free range for a little while I noticed the rooster's comb and wattles were black. He was out less than a minute and sat down rather than foraging. His comb turned back mostly red in the time he was out. When I put him back in he almost instantly laid down. He's about a year old. A Buff Orpington. I also have 4 BO hens and 2 OEG banty hens, none of which appear affected. We dewormed everybody about a month ago with Valbazen. We are going to fix up a cage and bring the roo in for the night. Any suggestions on what might be the problem and ways to treat it?