I don't know cold be wrong with OPs chicks, but my girls catch colds!! It doesn't seem to slow them down, but sometimes one or other of my hens gets a clear discharge from her nose and sneezes a lot. Usually the point I notice is if I cop a sneeze in the face when I'm cuddling them - eww! It clears up after a few days and so far has never been bad enough for them to need special treatment for it.
