Our barred rock roo has been acting strangely the past few days. We noticed his comb was starting to change colors the other day. Instead of the vibrant red it has always been, it has started to become bluish/black at the tips. He was very lethargic and feathers droopy two days ago. He isn't showing signs of injury. Today his crown is less red and more whitish and flaking looking and has started to flop. He doesn't have any sort of eye discharge, no pasty bum, no sneezing, wheezing or coughing. He is still slow moving but feathers are no longer droopy. He seems to be eating and drinking normally.He goes out with the rest of the flock but stays off by himself most of the day. He was our Alpha roo. Dont know if he's being bullied by one of our other roos or not. Any suggestions would be helpful. Thanks in advance.