We've had 8-16 chickens for the past 4 years. We got a variety of breeds. We've been very lucky with predators and also lucky with illness.
We've had 4-5 chickens get poopy but over time. Most have recovered after a cleaning with no associated lethargy. We've had two, both original Australorps get it really bad. After we cleaned them with warm water, give them yogurt, keep them warm, and made sure they were drinking, they became really lethargic, their bottoms get red & swollen and after 3-4 weeks we have to put them out of their misery.
We thought it was perhaps localized to the Australorps. But now, one of the original New Hampshire Reds has the same thing! We don't want this to end the same way!
Pictures are attached. We haven't seen mites or lice (but perhaps we don't know what we are looking at!). We haven't vaccinated or wormed or anything. Just layer pellets, fresh water daily, good kitchen scraps, and time out in the yards every few days. Any advice would be appreciated! Thanks!