We received a full-grown rooster from a friend. He said the rooster walks, then falls over. I took him home and allowed him to walk in the yard for a couple of hours. He crowed, flapped his wings, walked around , ran, ate well, drank plenty of water and seemed to be in perfect health. After a few hours we put him in the coop/pen with the other chickens. He did fine for a while then suddenly fell to one side and started "break-dancing" flapping his wings and legs pushing his body in a circular motion on the ground. I've googled everything but cannot find any indication of what may be causing this. We have removed him and placed him in a separate cage by himself so we can observe him but now I am also very concerned about the other chickens should his condition be contagious. Please advise.