http://www.internetjfs.org/articles/ijfsv8-5.pdf This is a very useful article. I have chosen not to treat sick ones. We are culling those with symptoms. I spent a lot of money on incredibly good quality stock - I am not risking anything. Plus no treatment has been proven completely useful. Plus most of the affected ones are cockerels and do not 'need' them anyway. I have way too many of them and there is no way I am pawning sick chickens onto another person.
If you look up treatment you are going to find a huge range of advice. Some say cull, some say treat with antibiotics, some say it won't help, others say this...that - it gets overwhelming fast. Because of this- I choose culling since I would culling them ANYway were they completely healthy. Too many roos. Plus all I can think about is them walking around with a compromised immune system- they will be the first to catch whatever might float around (whereas a healthy chicken might not be susceptible normally) and the he could give it to the other chickens. I tend to overthink things and want to be extra safe though.
Anyhow that's what we are doing. Plus spraying the area of the coop down with ACV. My husband needs to move the waterer and we need to something about that area of the coop still because now that it's been molded it's going to be a constant problem. :|