Last week we had very low temps around -20 and I found one of my chickens stuck in a nest box. She somehow managed to get her right foot stuck. It seemed to be frozen solid so I brought her inside. I noticed her wing must have gotten some frostbite as well. It looks like it is infected. The tip of her wing looks black and smells bad. It's hard to see in the pic but the wing is crusty with infection I would assume. Should I give her antibiotics?