I'm new to chickens. Got my first 14 hens (production reds) and 2 roosters (true reds) about 6 months ago. They were all about 4 months old when purchased them. Then added 27 chicks of several breeds (ameraucanas, barred plymouth rocks and true reds)... then 10 more welsummer chicks... then a few more... you get the picture! I was hooked and loving it. All was good, life with the birds was great... started getting plenty of eggs and just sitting with the birds was soooo relaxing. We named several of them and so on. A couple months ago I got 13 adult birds from Callahan's in Austin. 3 were real pretty birds but they just didn't know what breed they were. I asked everyone and the manager even came out and said he wasn't sure (I think they got them from a local farmer maybe). He gave me a really great deal on them because he said they had been there a long time and were starting to pick at each other. They were loosing feathers on their backs. I asked if they had mites or were sick but was told that they just needed to get out of the small holding pen they had been in for way too long... so I got 13 of them (9 were true reds and 3 were unknown, 1 was a cornish hen that i didn't mean to get). After having them for about a week I noticed the new birds were sneezing and coughing. A few days later they were gurgling and had labored breathing. I looked on the forums and found out about Tylon and gave them shots for a few days. They got better but I noticed my other birds starting getting sick! AND NOW MY ENTIRE FLOCK IS SICK! I didn't know about quarantine procedures. I just didn't know at first. I've now been fighting a battle to get all my birds better. Shots every night. they get better then others get sick and it spreads all over again... shots for a few nights and they get better - then a few weeks later it starts again! So now I'm facing the reality that I have to kill the entire flock. My wife is very upset and I just don't know if I can do it. I don't even know HOW to kill them. I've read that I have to clean the pen with bleach and get rid of all the hay I use on the ground. The birds are in a run of 80 foot by 16 foot with a roosting house at one end. I also have laying boxes I made out of milk crates. Is there anything I can do to keep the birds? What are my options? If not, how do I cull them?