wow, that is so similar to what is happening with two of my hens, about 23 weeks old. No wounds, no evidence of bumblefoot; first afflicted hen, a RIR, acted listless, had eyes closed a lot, but had good appetite and drank water OK. She's doing much better now, but still limping a bit.
Second hen is a tiny mutt, barely weighs 3 pounds I bet. For a week have been soaking their feet in epson salts and spraying neosporin on as well. Based on yesterday's postings, I changed out straw to pine shavings, disinfected with Nolvasan. Hens are separated from others. I inherited these hens, not sure if they had good diets that included oyster shell, but from day 1 (I got them two weeks ago) I have been giving them fresh greens and oyster shells. I'm going to add some aspirin to their water in the a.m.! Perhaps we can keep in touch about this thru the forum.