It's possible that you are dealing with more than one pathogen, and I think Denagard doesn't treat E. coli or pseudomonas aeruginosa, which are two common respiratory bacterial infections.Today is day 3 on antibiotics, most of my chickens have drastically improved, all except my silkie and her 2 salmon favorelle chicks (hatched the 25th of this month). They are still showing all symptoms. Should I continue their Denagard for another 3 days?