I have a couple of hens, they are second year instead of first like the others, and they seem fine, but, there is runny poo on the back of their feathers. I have 30 birds and a couple of them have poo on their butt feathers. The other ones walk around and their butt feathers are clean as a whistle. These couple have not been sick before, no one seems sick now, I did their de-worming several months ago (maintenance). I have checked their feather bases and there is NO sign of mites or lice. No one else has "caught it" or is having a problem. It has been a couple of weeks...still have it. Checking the poo in the coop and runs and there is nothing that is noticeably runny that would associate it with these hens....It is the regular brown/green/white streaked colors. Any ideas? I would hate to miss something, but, hate to treat randomly without knowing what is going on. No docs around here to test poo. Please give ideas.