We have two black sex-linked girls, hatched in May, and one buff orpington, hatched in July. The feistier of the two black hens, Fiona, has a rattly-sounding chest today (Monday) and all three have diarrhea (caramel-colored). They are free-range during the daytime hours while I am home, and inside at night. Their boxes are filled with pine shavings. I change their water daily and bleach their water dispenser weekly. When anything gets damp, I change the bedding. We did have heavy rain last week and I changed the coop Friday. We have had regular egg production from Fiona and Millie up until yesterday. No eggs yesterday or today. In the past several days, these things have happened: 1) filled the bird feeder for the first time since we've had the chickens, and they went bonkers over the seed underneath. Migratory bird exposure to something? 2) 4-yo dd picked up chickens, and I know she had one of them upside down yesterday. Yes, we had a talk and she is aware this is not acceptable behavior. I read on a post here somewhere that they can get bacteria from their...crop, yes? Sorry, this is new to me, and I am learning as I go. I went to my local feed store, who recommended a broad-spectrum antibiotic, but I hesitate to use it (what if it isn't bacterial?) without knowing better what I am dealing with. Fiona is not gasping, open-beaked, or mucus-y, only rattling and not eating or scratching. Edit: Monday afternoon--she is now coughing on occasion and fluffed out. Any ideas? Thanks in advance.