Hello, I have had chickens for about 3 years now. The first year went well. Nearly all my store bought chickens grew up with no problem. The second year I really got into silkies and incubating. I ordered eggs online and hatched them out myself. They did fine until about 8 - 16 weeks old and then I would go out to the coop and have MASS deaths. Sometimes I would notice a chicken laying around like it was paralized but often I would just go to feed or water and have dead chickens. I think it was probably Mareks. Last weekend I went and bought some Americanas (easter eggers) and some Maran's from some local people. They are not vaccinated for Mareks. I also ordered the Top Hat Special from Murray McMurray and I paid to have them vaccinated before they are shipped which will be next week. I have my chicks in the house right now because I am terrified of putting them in the coop. Now I haven't had a dead chicken in there for over 6 months but I am so afraid to use it. I can't keep chicks in the house forever and I have a nice little coop with a fenced yard.... any tips on how I can "clean" or "sterilize" it? I have already shoveled out all the old shavings and put in new and I raked all the leaves out of it that fell in the fall. Can I just bleach the heck out of it then let it air out for a bit or is nothing really going to help prevent my local bought chicks from catching it? Thanks. Also.... Do I need to keep my vaccinated top hats seperate from my non vaccinated local chicks?