I'm raising my last batch of 100 meat birds for the year and they were growing really well. I was going to have them out on pasture like I usually do, but it got really cold so I've been raising them in our barn on hay. It has decent ventilation and windows so they get natural light. I hadn't lost a single chick and got to keep the 5 extras that the hatchery sent, but a few weeks ago I found one that looked like it was having trouble breathing. The next morning I found it dead. I didn't think it was a big deal because losing 1 out of 105 is very good, but about a week later, I saw two more that seamed like they were struggling to catch their breath. I took them both out and killed them for dinner which I usually do with the weak birds so they don't go to waste. After they were plucked I made a cut near the vent to gut them and their abdomins practically popped with thick, yellow tinted liquid. Almost the whole inside of the birds were full of the gross liquid. I burried them in a pile of woodchips away from the rest of my chickens. The rest (now 7 weeks old) seamed fine until today when I got home from school. There were two more lying dead in the barn. They were both bloated and I could tell they too were full of the "mystery liquid". Does anyone know what this infection could be and how to treat it? I really need to know soon because I'm butchering them all in a week and I want to know if they're safe to eat. It would be a huge waste and loss of money if I had to throw them away, plus my dedicated customers wouldn't have any chicken over the winter. Thanks!