Well, I've noticed something on my chickens combs and I want to know what it is and how I can treat it? It is like black, white, & grey crusty stuff. Haven't tried touching it, lol I'm too grossed out.
That looks like dry fowl pox or avian pox which is a virus spread by mosquitoes, then spread from chicken to chicken in a flock. It usually lasts 3 weeks, and later they are immune to it. There is really no treatment necessary, but there is a wet form that can get into the mouth and throat causing serious breathing problems. If you have any with breathing difficulty, look into their mouths. Here is some info: http://edis.ifas.ufl.edu/ps044