Baytril is an older medication many bacteria are now resistant to it. I understand the problem but I would get on the phone and speak to a vet whom is willing to work WITH you they will have the experience need to properly deal with the problem. I would really recommend a culture be done before dosing with drugs as drugs often purger the culture. Any decent vet will be able to send the sample out to a lab.

The next questions is what is up that is causing the ri in the first place. Typically it is attached to temps (ambient air often) and poor ventilation. So the next question is what are the ambient air temps in your rack and how many holes do you have in the tubs?

there was a poster a while back whom had no holes and over a period of time all the snakes got RI he had, although he insisted they had enough ventilation the whole time...