We are first time chicken owners and got our 4 girls about 2 months ago. They are about 10 months old. 2 weeks in one stopped laying eggs and holding her tail down. Thought it was because I changed the food and she would adjust. 2 more weeks later she started having diarrhea that had gotten increasingly worse. 1 week ago another chicken starting hacking and trying to clear her throat. I'm treating for cocci an worms right now but it's been a few days and they are not looking better. I don't want them to die but I do understand that can happen. But I really don't want them to suffer. Does anyone have any ideas what could be wrong