some of my chickens are showing black spots on their combs. Very tiny spot on most. It seems the worst on the rooster. He's been like this for over a month. Now I noticed he is sneezing sometimes. Some of the hens are sneezing as well. I looked in his mouth and didn't see any thing odd. No yellow build up or any of that. I didn't check the hens' mouths.
Can anyone identify the problem and identify proper treatment