My flock has gotten sick not all of them but most. Their eyes are swelling shut drainage from their nose and coughing and sneezing sounds like they're congested. Some are not that bad but the rooster has done died and 2 more are very weak and won't eat or drink they won't even come out the box. My neighbor gave me some medicine because one of their chickens done the same but I was wonder what should I do to get them to eat? I know its not good for them to go without food or water. And what could this sickness be its very confusing cause some are fine but some are badly sick.