A couple days ago, my roo's comb had a few drops of blood on it. I thought he maybe cut it on the wire Or something. Today, most of his comb is black! He acts normal, eats, and struts around but I am worried aboout it. Temps have went from 60's to teens quickly...could it be that? I have just the one roo and 5 hens. They have a large run so nothing Can get to them. Any advice is greatly appreciated!