patientz3ro all true but Baytril can be bought off the shelf now and has been used as the first 'hammer' for what 20 years? It has been used to treat RI and just about every other infection around. It is so often used and in so many cases when there isn't even an infection at all or for durations that are simply too short to be effective that many bacteria have become resistant to it, my vet in workshops with the big vet names (Jacobsen, madder) has learned some believe more than 50% of ri cases cannot be treated with Baytril. The same way with people, antibiotics are rotated the same broad spectrum being used by 90% of doctors to treat everything for 20 years is not going to be effective. I am assuming you are a practitioner? You know that resistance is a huge issue.

I would suggest that a culture is the best way to discover if antibiotics are needed (not actually a respiratory issue especially as many vets have little to know experience with reptiles so mis diagnoses are very common) and which antibiotics many be the most effective or at least what ones are not.