Does this look like frostbite? Our big girl Pancake has been having a hard time lately. She's been attacked by one of the other girls in the flock and got bloodied https://www.backyardchickens.com/t/858096/help-chicken-attacked-and-bloodied-by-another. Now this black tissue seems to be getting worse (or at least Ive noticed it more since she's been inside recovering from the attack). She had this tissue damage prior to the attack. We had a real cold spell here (-25*C). It was around that time that I noticed the black tissue. That was about 2 weeks ago maybe? I treated it with 10% iodine solution today. It was her first treatment. Is there anything else I should consider??