Two of new birds are sneezing and one has a clear runny nose. Both are alert, eating and drinking but puffed up like they are cold. I immediately isolated them from the other 7 (who are a bit older) into a dog kennel in the house where I can monitor them better. I made the kennel draft free, added ACV and some oxytetracycline to the water. They seem more alert this morning but still a bit puffed up and my house is 70*. Their stool is normal and I only see clear discharge from one. What else should/can I do? In 35'ish years I've never had a sick chicken before.