My dear friend has a flock of what were healthy chickens. Today, however, she noticed that 4 of 42 chickens have very swollen faces and swollen joul area (under the beak). This condition would have began no more than 72 hours ago (she was away for a few days and prior to that she was with the chickens every day). It was this morning she noticed the condition. Those animal affected have the following symptoms; the swelling, obsiously not feeling great (poofed up and a bit lethargic), they are still eating and drinking at this point, not sure about droppings. Any ideas would be a great help, she's not sure whether she should just put those 4 down. Thanks in advance for all your help!!