Do my chickens have a disease

[I LOVE MY CHICKENS!25]

I noticed my chickens sneezing a lot I haven't noticed anything else wrong except runny poop and out of five hens I only get one egg when I was getting five but I think the egg drop could be because of over breeding recently a bunch of my chicken got killed leaving me with 4 roosters and 5 hens two are aggressive and I haven't had a chance to get them out my poor hens are loosing feathers because of it could that be it or are they sick?

 

[sourland]

Stress increases susceptibility to disease. Get rid of the roosters yesterday for the sake of your hens.