I need some help. I have a sick chicken, with a chronic respiratory infection. His nostrils are filled with yellow gunk. Standard antibiotics, like the ones I can buy a tractor supply, haven't worked. I have ordered Tylan, and Sulfafimethadine. They both seem to treat different aspects of what my chicken is dealing with. Can I dose him with both antibiotics? Or is it better to use one over the other? Thank you in advance for all your help.