My rooster Penguin was treated for an upper respiratory about a week ago with injectable Tylan 50 one shot for three days. He was bad, breathing deep and breathing with his mouth open and sneezing/coughing. After the first dose of Tylan 50 he was better crowing and breathing a lot better. He is on Oxytetracycline and should be soon getting off of it (it's been a little over a week), but he still has a cough. It's very very cold here so we have him and his hen in the garage in a cage with shavings, a heat lamp, and bags of wood pellets and thick blankets on and around the cage to keep the heat in from the heat lamp. He is eating and drinking but he still has the cough. What should I do to help the cough? He has gotten better by 100 times but that cough is still there. What should I do?