I had a 24week old BO hen, she had paralysis that started in one leg and progressed, (not the classic Mareks position-one foot forward and one back), weight loss, and then yesterday I noticed her nostrils had turned black? They weren't plugged, or runny, but black on the inside, and down her beak a bit. What causes that? Either way she's dead. I was getting up the courage to put her down, headed out, and she was dead thank God. I didn't want her to suffer anymore, but I really dreaded the actual killing. So any ideas? I have a roo with similar symptoms, early stages, and he'll be heading for a necropsy next week before he gets much worse. I found an old pic of her sister, also died with same symptoms. If you look closely you can see a discoloration, like dirt in her nostrils, but in the end the nostril is literally black, extending down the beak 1/4" or more. Mold or fungus?