I don't ordinarily. Everyone seems to be OK for the time being (they luuuuuv the DE, rush for it when I put it in) but I do realize that it's not for long-term use. We change out the sandbox regularly and rinse the sand, so it won't stay behind.
I think they are just molting (a couple other hens are also losing feathers) but have been giving them DE in their sandbox every day, and vinegar in their water; seems to be helping. Everybody is eating and laying normally, so I'm just going to keep a close eye.
I did buy the vetermycin just in...
Thanks for this thread! Am seriously worried about my favorite hen, who looks just like this (although we did have eggs yesterday) Am still doing some treatment for mites and lice (diatomaceous earth in the sandbox, and apple cider vinegar in the water) just in case.