That's interesting. I've never heard of it. Did you have a thread where you treated your chicken? (with photos too ) I'd like to learn more about that!Foot Parasite is something I discovered a while back. It's gray colored, and sometimes will harden like a rock, but isn't a rock. So far from my studies, I've only seen it in the webbing of a chicken's foot and it barrows up into the leg. On the top of the chicken's foot webbing, it looks like a bubble, and possibly like it's Bumble Foot, but it's not. To treat it, I use tweezers to first remove it, and hopefully in one piece. Next I would pour Peroxide into the whole. This worked on a mild case, but on a worst case, the whole doesn't appear to have a bottom, and the Foot Parasite came back. I don't know if that's what it is actually called, but in my research, I couldn't find anything that matched it.