I have an Americana that for several weeks has had a white growth on her comb. It looks kind of fury, like a white mold? None of my other 12 chickens have it, and she seems to be acting healthy. I get eggs from her almost every day and she acts normal. I can't seem to find any information on this, any ideas? I'm wondering if it's something fungal? I live in Phoenix, AZ, so it's very dry here. I'd appreciate any help. Thank you.