Yes, Ivermectin should clear any mites up. But the bird is vulnerable to re-infestation if your flock has mites, so it's a good idea to change their litter and spray down the coop, including nests and roosts, to clear the problem up for everyone. Permithrin is a good product to use, but if you do decide to do it, follow directions on the bottle closely. You should also use vaseline treatment or Ivermectin on the rest of your flock but there will be a period where their eggs won't be safe to eat if you use Ivermectin. I believe you have to wait at least two weeks before eating them again. No wait period with he vaseline treatment.
I can't really think of anything besides mites that would cause this problem, unless it is just old age or a skin problem. But if it doesn't clear up after a while, get back to us, and we'll try to figure it out. Photos of the legs would help. Good luck-- I hope it all works out.
