Try some baytril and you'll see why he hates it! :lol:
I put a little carrot or apple juice (make sure there is no added sugar or sweeteners or anything except pure juice in it, check labels!) in a shot glass, add the baytril to it, mix and suck it up in a 5ml or 10ml syringe, make sure you get it all. My bunny Barney then just sucks it from the syringe, make sure you push the plunger down very slowly or you'll do it too quick and there's a danger he may choke. It's very useful to teach a bunny to take things from a syringe willingly, it enables you to give medicine without stressing them, and is a godsend if the bun needs to be fed liquid food to keep his gut going.
When I had to give it to my hamster, I mushed up a teaspoon of fruit and mixed the baytril in. The key with both methods is to disguise the flavour in something they like. If you make it an unpleasant activity then you will make him more reluctant each time to take it, and you risk damaging your friendship with him.
Has Hannibal been diagnosed with snuffles then? Lots of bunnies on here have snuffles, including my Barney. The first thing to do is to check if your vet is an exotic vet or has an interest in rabbits, as rabbits are classed as 'exotics' so normal vets dont have to learn more than the basics. A good vet that is willing to try new things and work with you will really help.
Your vet probably has explained this already, but there are a few different bacteria that cause snuffles, although the most commonly known is pasturella. Baytril is usually prescribed first as it is effective against pasturella, but dont worry too much if you see no real improvement, as you may need to try other antibiotics, or a combination of them, in order to find one that is effective for your bun. If you do find that the baytril is not working, a Culture and Sensitivity test from his nose will tell you what bacteria you are dealing with, and allow your vet to pick an antibiotic that is effective against that bacteria.
I would also keep a sharp eye on his hay intake, as snuffles can be related to dental problems. I would advise a dental check on the back teeth the next time you go to the vet. That will show up any misalignment of the jaw and major problems, but some cant be seen unless under General Anesthetic. Tooth root problems you cant see without an xray of the jaw.