My vets no longer use Baytril for chameleons. Has your chameleon been seen by the vet or are you treating him yourself?
In my Vet's case Baytril is an option but not the first choice. I've worked with the stuff for over two plus decades and have seen quite a bit of results myself in dozens of different type of reptiles, some good and some not so good.
I've used Baytril injections before. Baytril is quite caustic and it is painful. My vet is board certified in zoo medicine and he finds that Baytril injections can be more effective than Baytril given orally. Anytime I've given Baytril injections, the vet has prescribed a series of five injections given every 48 hours.
Yes, their skin marks up black around the injection site, and sometimes it can be quite a big mark.
Don't worry, the mark will fade.
I love how you added that line that your vet is a board certified vet to support your point of view in this. Personally I've dealt with a number of "board certified" people and there have been as many good ones as
idiots. The phrase doesn't mean as much as it once did. I doubt your vet has rescued or rehabbed the number of Chams I have. But lets not split hairs shall we? The majority of chams I've seen where injections are used don't fare well. Now admittedly there are many possibilities for that- not the least of which could be the animal was just too far gone in the first place. That aside, the average person is not going to always be able to inject properly, they make mistakes too. Also the chams do not tolerate the extra stress as compared to say an iguana, something a lot of "board certified" vets don't understand.I met one vet once who told me it was safer for him to inject than to get the animal's mouth open to give it oral meds, so forgive me if I can care less about your vet giving you reason to feel injections are more effective.
When I try to provide to information or even the more rare venue and teach, I firmly have seen that simpler is better for people asking for info on the site. Oral meds for a chameleon will work better for the majority of folks and when it comes to Baytril and as long as the stuff gets inside the animal it will do its job.
Less stress in a cham = better chance of recovery. Giving a cham something orally or via injection is of course stressful, but orally is going to be easier.
To the OP, gratz on your animal improving. Have you determined the cause yet? If not you are potentially going to have a relapse when the meds are done.