Hi Robin,
I did some searching and could not find any data about oral availability of Baytril in snakes. However, I did find that another antibiotic, azithromycin, has been shown to be absorbed through the GI tract in ball pythons and reach effective plasma levels. Also metronidazole, an antibiotic used in anaerobic infections, has been shown to be absorbed through the GI tract in yellow rat snakes. So it's certainly feasible that Baytril would also be absorbed through the GI tract, but no one has done the studies yet.
CritterVet