- One of our Muscovy ducks has been dealing with scabbing of her caruncle for months. She also had been breathing a little wheezy, but the wheezing has gone away and her scabbing seemed to get better. I thought perhaps it was fowl pox, but it hadn’t spread to the others. Recently, the scabbing came back and the skin under her feathers looks raw and her eye is beginning to foam. It has now spread to 2 other ducks in the flock. What is this? How can I help them? I see no mites/black dots and other than the looks, they’re all very lively and running around the yard.