One of my red star hens (about 2 years old) was coughing and sounding very congested. For the past 3 or 4 days I've had her in one of my rabbit hutches for the past 4 days. I've been giving her duramycin. She has stopped coughing and her breathing sounds fine now. How much longer should I keep her on the duramycin? Should I be giving her anything else?