Well....I am going to say something here that many will find surprising.....I am impressed that your vet went "outside the box". I don't like Baytril, don't use Baytril and feel that it is the most abused drug ever in veterinary medicine...but I have to give props to the vet for the effort. The idea behind transdermal medication is that is is useful for people that can't or won't do injections. And with most any animal, especially a rabbit, if you can do anything other than oral antibiotics, that is always a plus. There are a couple of reasons for this....first, you all but eliminate a bacterial issue in the gut if you avoid oral meds. Next, many people don't realize that pH in the gut has an effect on drugs....some don't absorb well in acidic climates and some don't do well in alkaline climates. Injectables or transdermal eliminates these concerns.
I also think you are correct in feeling that a culture would be in order. Unfortunately with Pasteurella, it might not always culture. This is due to the fact that Pasteurella is a faculative anaerobe and may actually die during the culture. If we do culture due to presentations of a bacterial infection (primarily discharge and fever)....we treat for Pasteurella. We have also seen other bacteria in rabbits but Pasteurella is by far the most common. And the most common location is upper respiratory but it could also be ocular, vestibular or dental issues causing this concern.
As far as drugs....assuming it's Pasteurella....my current drug of choice is Zithromax. I have also used one of the newer Fluoroquinolones called Zeniquin. While it is in the same class of drug as Cipro and Baytril....it has some advantages over them. Convenia is also a drug (safe as an injectable only) that we have used successfully. Chloramphenicol is a very powerful drug but might not be the ideal choice at this time....this one might bestbe saved for a later day. Baytril and/or Sulfa type drugs would not be at the top of my list for treating this potential infection.
Randy
