Hello all, New to backyard chickens and starting off with an unfortunate post! Last week I looked on craigslist for chickens nearing laying age, I found a woman with four hens and went to her house to look at them. I ended up buying them out of pity, because she had them in terrible conditions. Tiny cage, corn only and no run. They are reported 8 months, and have never laid. I am feeding them Layena, Oyster shells and they've had a little beef liver. Moving their coop/run around the yard every two days for fresh grass. Constant fresh water with a little bit of apple cider vinegar mixed in. They've also had a little bit of yogurt. This chicken appeared healthy when I got her home, but today she didn't come down from the coop into the run until around 9 or 10 AM. Her feet are terribly swollen and she has lost the feathers on her underside (pictures above). I noticed feathers in the run yesterday, but chalked it up to pecking. After the photos I rinsed her feet in epsom salt water, and the dark matter which I believe is mud or poop, and her normal skin came off some. She did not have bumble foot when I got her. Another chicken was having trouble walking and standing still, and has a bald patch on her back, but has since improved and is walking fine. The two others are both bald near their vents. They mostly sleep crowded around the nest box, but have seen all of them on the roost at certain points. Any help would be appreciated!