Bleach, if you have a fruit tree sprayer put a high concentration of bleach and water in it and spray the crap out of the coop, (take all the shavings out first) then after spraying everything lock all the doors and windows, if your really paranoid tape all the cracks or use plastic, let the bleach sit for a few hours so the fumes can get into everything, the dirt run try shoveling the top 6 inches of dirt out and refilling it with other stuff from your yard, or lightly bleach it (probly a bad idea, terrible for the environment, but ounce it dries its completely harmless, so i have no idea) Just a word from the wise, be very careful around bleach, i'v been using it for years and it seems harmless but in high concentration it can be dangerous. I had to fumigate a coop a few weeks ago, my hands were in and out of the bleach H2o mix all day, a few days later I ended up with chemical burns all over my hands, i also got the mist around my eyes which screwed up my vision for a day or two and will probably cause problems down the road. While working in the coop i inhaled small amounts of the bleach, which was unavoidable while in the area, later that night I had random asthma attacks, serious ones, I'v always had sports and allergin induced asthma but not random attacks, i was just sitting on the couch watching tv and suddenly I couldn't breath, luckily they passed quickly. That night, or morning, I woke up at around 12 AM, could barely breath, chest hurt, stomach was cramped up so bad i had to crawl to the bathroom cause i thought i was gonna puke, the feeling passed. I'v been working around bleach and other fun chemicals literally since i was eight and i'v never worn any kind of protection, please learn from my stupidity, wear rubber gloves, goggles and a ventilator if you have them and take lots of breaks. Just a rant, when i get going i don't know where to stop... But yeah bleach is probly your best bet. Does anybody know how long a poultry disease can stay dormant and transmitable if it was just sitting out in the dirt?