Four Nights ago, a opossum got in my coop and got at two of my chickens. Fortunately he was only in there a short time as I happen to hear them clucking at about 11:00. The buff orpington had a good attack on her leg and lost a lot of feathers and had a cut. I noticed the last two days her skin on the leg is turning greenish blue. She still walks on it fine and is eating well. Is it infected? Do I need to get antibiotics or is it a lost cause? Thanks.