I think if this is an ongoing problem an x-ray could be helpful. I think since you have not had success it might be helpful to do a culture.

With all of Nate’s respiratory problems, we’ve pretty much the gamut of tests. His problems were much more severe than what you’re dealing with (from the sounds of it), but I did a culture and sensitivity on him, once we had tried the second antibiotic to no success. The culture came back showing he was infected with both Pasteurella and Bordetella and the sensitivity showed that the only antibiotic he was receptive to was Tetracycline – not one of which we had tried at that point… so it was definitely helpful for us. I ended up getting x-rays done on him and he was given the all clear for pneumonia, dental problems, etc. So it wasn’t really a necessity, but I felt better knowing that I could rule that out.

Has your vet recommended anything? At the time my vet recommended the culture & sensitivity and said if that came back inconclusive, then we should take xrays. I decided to do both at once, only because when I got him, he was on deaths door.

I think it’s good you’re getting the C & S. Nasal swabs should be deep to be really effective, sometimes this is not possible except with a little snootful of anesthetic. It should be at least two weeks since his last round of meds to be accurate. I had xrays done on Mimzy after multiple nasal infections/antibiotics/swabs only because we’d run out of other options.
Baytril is a low level healer, so if it’s something deep in the sinuses or even the bone, this won’t do much. I can’t give injections properly, but Pen-G is supposed to be good for deep tissue infection. Also antibiotics have to be used longer than just the regular ten days or you get nowhere and the germs just build up resistance.
I’ve found that Mimzy not only has a minor defect in his sinus cavities, (typical in lops), but he seems to be allergic to a lot of hays. 0_0 Kinda sad for a bunny.
I hope your vet is able to provide some relief for Wooly. Sending healing vibes for him. xx

Poor Wooly!
I’m sorry I have no advice as I have no experience with something like this but I hope your vet can figure this out soon.

Sending healing vibes for your boy!

{{{Wooly Pouty-Pants}}}

Mmm…
id have mixed feelings on the approach but i tend to overthink things…
If his own immune system can deal with build up in bacteria then that’s great! But you certainly don’t want to leave it to long if not seeing results.
Have you found the Benadryl has helped so far?

Something I’ve learnt: not all Benadryl is the same! Like in the UK the name is used for a different med altogether. Then there is the allergy versions, paediatric version etc etc.
It’s the ingredient diphenhydramine that is used in veterinary (that I’m aware of).

We used benadryl for Mimzy too. His issues were only marginally resolved with it. We never really found out what was causing his problems.
Now that he’s had head tilt I have to presume it was something like E.C.
I hope Wooly will feel better soon. And that Leopold doesn’t become a benadryl junkie. ((((((Vibes))))))

What about doing some nose drops?