I have two hens that tend to have dirty rears, like all the feathers on their bums sometimes are wet looking with white and black poo (I'm assuming is what it is). The mess isn't chunky, just like they sat in diarrhea. They act fine, eat fine no obvious stuff going on. I've tried to inspect them when they're roosting, which is the only time I can get close to them, I bought them from a gal who was selling her flock and so they won't let me near them :/ So, on the roost the tend to sit with their butts toward the back, so I have a really hard time telling who is who and if I mess around too much my roo gets agitated and then everyone is stirred up I've wormed them once after I got them, which would've been about May. I haven't done yogurt in awhile, could try that. Anyone have any help they can offer? I would think if it was coccidia it would've spread to the others and it hasn't. Could be mites? Man, how do I get ahold of them to take a peek?? Could just be they need the yogurt??