I have a 4 month old Speckled Sussex, that is very lethargic, the neck retracted so its head it tight to its body, feathers are fluffed out, and she keeps here eyes shut. My wife just picker her up, and tipped her over, and a bunch of milky white slime came pouring out of the chicks mouth. Her breast area is also VERY squishy (almost like its filled with fluid), not solid like others. This will be the 3rd one to have this same issue in a matter of weeks, the other two died. They are in a coop with 11 chicks, 5 adults, fed only fast grow and meal worms, and maybe a little (very little) scratch just a couple of times. Let me know your thoughts!!!!