I believe that one of my Easter Eggers may have worms. She seems totally healthy, and she's laying well. However starting a few weeks ago, I've noticed that the feathers around her vent remain filthy all the time. Because she's white, this is very obvious. Here's a photo I snapped of her walking away from me so you can see what I mean. I'm thinking that this could be the result of worms. I have never wormed my very small backyard flock, but I think I need to start. I do use ACV in their drinking water, and I sprinkle diatomaceous earth around their coop, run and nestboxes, which I keep very clean, so those items can be checked off the anti-worm list. I'd be really grateful of others would share whether, when and how you worm your chickens. Please be as specific as you can with regard to brand names, administration routes (add to water, give in shot to chicken, etc) and how often you do the worming. Many thanks!