Hello I am a new chicken owner and have a total of 9 girls, a mix of Orpingtons and barred rocks. They live in a nice large coop with a run and I clean the coop about once a week. We let them free range whenever we are home. About a week and a half ago I noticed one of the Orpingtons had a very messy bum. I gave her a bath and didn't think about it again. A few days later it was in the same state and one of the barred rocks was looking the same. I didn't notice any worms or anything in their poop but decided to try and deworm them. I gave them oral Ivermectin on October 17th with no real change. They continue to have diarrhea and are getting increasingly weak/falling. They still eat and drink some. I gave them two days of "stress aid" (an electrolyte & Vitamin mix) and started them on tetracycline last night. I just dont know where to go from here. Today the Orpington was just laying on her side in the straw and didn't try and get away from me when I patted her which is unusual. Their vents look healthy and they don't feel egg bound. They are just having this persistent liquid poop with some loose green material in it. Does anyone have any other suggestions? It is breaking my heart to see them like this. They are quarantined from the rest of the flock and the rest of the flock have shown no symptoms. They are out in our baby barn in a stall right now... I was hesitant to bring them inside because we would be putting them in the basement where the wood furnace is and I was nervous of them becoming to accustomed to the heat and not be able to handle the cold of the coop if they survive...but im thinking now maybe being warm would take some of the stress away.