Hi there. I’ve had chickens for almost 20 years but it’s been super hot here and even though they’re let out every morning to graze in the yard, I have an old hen who now is making a clunking sound with every breath. I’m supposing she may have a respiratory infection. The only antibiotics I have are cephalexin and Cipro. I wondered if anybody knew if it would be good to try one of those and what the dosage might be for an average size hen?