When I went out to feed the chickens I noticed one of my cockerels was limping. I immediately thought bumble foot, so I took him inside and cleaned him up. When I checked his feet, I found no sign of bumble foot. No broken bones or wounds either. I can't find anything that would be causing his limping, but the poor guy is hopping around, barely putting any weight on one of his legs. All of the others seem to be fine. Any ideas on what this might be? And how I can help him?