This is probably going to be pretty long, sorry in advance, I just want to make sure I get all the details. So near the end of November I had this rooster who was about two and a half. I went out in the morning to let everyone out and he was laying in the corner not looking right. His face was kind of blue, like he wasn't properly breathing. I picked him up to take him inside to try to figure out what was wrong with him and so he wouldn't anyone else sick. He started to throw up all over. His breathing was raspy, like he was choking. I took a flashlight and looked down his throat, but I didn't see anything. He was acting weirdly for three or four days amd then suddenly he was fine. I kept him away from the others for another day to make sure, and he was still perfectly fine so I took him back out with the others. No problems for a month. Then he threw up and acted weirdly again so I took him back in the house. That night, I woke up the hear him choking. I took him out of the cage trying to find out what to do. After a minute, he started shaking and throwing up, kind of like a seizure, and then he died. I couldn't find anything even remotely similar on the internet for what could've been wrong with him. He also has this string of drool hanging out of his mouth, but I figured it was just like throw up or something. All the other chickens were perfectly healthy. He was a Cochin mix, a chicken I hatched so I have no idea who he was mixed with, my guess was a Plymouth Rock. Then in March, I went out to check on the chickens and one of the americanas, about eight years old, was lying on the ground, shaking with drool hanging out of her mouth and her comb and wattles were blue. I took her inside, inspected her and could find anything strange other than that she had really runny, extremely smelly, dark brown poop. I thought maybe it was an egg binding, so I took her and soaked her in warm water with espom salts. After a few hours I went out to check her and she had thrown up a lot and was shaking really bad. She died a few minutes later. Then today, I went out this morning to check on everybody and everything was fine, I fought with a Rhode Island Red to get the eggs out of the nesting box and after a bit I left. I went out about half an hour later thinking I forgot something, and the the Rhode Island Red was lying on the ground dead, wattles and comb blue, drool coming out of her mouth. She was fine half an hour ago and then she was laying there dead. She was about nine years old. It also happened a fourth time, but I can't remember any of the details except that it was the same basic thing, she was perfectly healthy and then just started shaking, threw up, and died. She was a turken, about three years old. I don't know what's happening, I can't find anything anywhere about what could be wrong. Any help would be greatly appreciated, I don't want to lose anymore of my flock, they're like children to me. After awhile of searching when the first rooster got sick in November, I found a vet and took him there, but it was over two hours away, very expensive, and the others died before I even had a chance to take them. When I took him, he said that something seemed wrong with his crop and he might have a fungal infection. They gave him a crop bra and ran a test, but it came back negative.