I have four week old chicks that I hatched (from my own stock) out of an incubator. We had five but had to cull one, its legs had pretty bad deformities and it seemed like it was struggling to breath. The remaining four seemed pretty healthy aside from getting a little pasty butt which I've been keeping a close eye on. Now one of the chicks seems to be breathing heavy today, it actually opens its beak as it breaths, this one has also had pasty butt more than the others. She seems more lethargic/sleepy than the others. I don't have a thermometer in the brooder but have been adjusting according to their behavior. We have clean the brooder every other day and I'll probably clean it again today to keep a better eye on things. Their poops look pretty normal though I did observe the one that is breathing hard have one poop that looked slightly foamy. They're on unmedicated starter and I've been very careful to wash my hands in between going to take care of them and my big chickens. I'm hoping it will be okay but if it doesn't make it I am desparately hoping it's not something contagious.