I am a first time chicken owner. I have three 25 week Black Australorps who have been laying for a little while. I just wormed the girls for the first time and now they have started coughing and one has nasal drainage. I also introduced two new four week old RIR chicks to my group three weeks ago. They all free range during the day but have separate roosting and feeding areas. The babies do have access to the big girls water. I wormed all the girls at the same time, but only the older ones have this cough. Any ideas what I am dealing with and what I should do? I started all on Sulmet just in case. I need some help but am not in a financial position to spend a lot of money at a vet.