My rooster Jerry has black on the top parts of his comb. I've also started to notice it blistering. I want to help him but I'm not sure what I should do. It's been really cold here and we have good ventilation in the coop. I'm not sure if he got frostbitten or if it was from his coyote attack weeks ago. There were small scratches. He acts normal. He eats and drinks and still crows in th morning. Would Vaseline or neosporin help?
It's most likely frostbite. You can put some neosporin (just the plain - NO pain relief stuff) on it gently.
Pictures of the coop? Some people think they have tons of ventilation, but it may be poorly placed or simply not enough.
When you say coop is well ventilated, exactly what does that mean? Pics of coop and vents.... Gary from Idyllwild Ca here