I have a rooster that is acting normal - eating, drinking, free-ranging, walking fine, etc. But I believe he has frostbite on his back toe (not sure if that toe has a special name). It's lost its claw, and is now a black stub. But again, the rooster seems normal. I have a coop that's heated, but it was below zero for about 2 weeks straight here. I'm sure that's when that happened. Just miserable cold, and the chickens never left the coop during those 2 weeks. Anything I can do for the frostbitten area? Or, could this possibly be something else?