I had a black japanese bantam rooster that generally was so quick that the larger roosters couldnt get at him, but somehow he came up lame. I placed him in a cage and he seemed to decide that he no longer needed to walk. I could not find anything wrong with his leg. no discoloration, no swelling and he did not seem to be in any pain. he continued to eat and drink just fine right up until he died. what in the heck happened?