All the chicks had the coccidiosis vaccine except for 8 of them (which I have a feeling these eight were not healthy as we got them from a local farmer and 5 of the 8 did not make it). Each bird that has died has had one or both eyes close up, like a chick form of pink eye. There was crust between the eyelids. They all had really high pitch chirps, not like the normal kind of chick noise. I have never seen them with any breathing problems and they don't have diarrhea, or at least not that I can tell because they are going outside all day long now and I have a hard time seeing it on the grass. They all have plenty of energy. They seem to be eating plenty.
Right now, I actually am treating one that yesterday had a puffy, swollen shut eye. I have put saline and neosporine on it, and today she seemed better. The swelling went down, but the eye seems to be gone, there is just a red membrane covering the eye. I think it may have been pecked at or got something in it's eye.
I had no idea chicks could have so many illnesses. Maybe I let them outside and they were too young...or maybe we should not have put both sets of chickens together (the set I ordered online and the set we got from a local farmer...even if they were the same age). I sure am learning a lot. Thanks!