I have 3 roosters that are showing signs of respiratory infections. I have them separated and heat lamps on them and I have used vet rx. I have la200 on hand and a few other things I use for my goats. I would call a vet out but it isn't practical for $8 chickens. Can i get some advice on what to do for them. I have already been told to cull them but I feel like there is something I can do.