Considering the crust is in multiple spots and has not gone away with wound topical treatment, it may be mites: https://wabbitwiki.com/wiki/Mites … or some sort of fungal infection.

I would recommend finding a different vet to have this assessed properly before trying any treatments (at-home treatments for fleas/mites is not recommended due to the need for rabbit-safe treatment, as well as proper dosing information). Rabbits must go to rabbit-experienced vets, so perhaps you can find one here: https://wabbitwiki.com/wiki/Choosing_a_rabbit_veterinarian#Rabbit_veterinarian_listings

Do not use any treatment which contains fipronil [Frontline® – Merial]. Fipronil is effective, however, serious adverse effects such as depression, anorexia, seizures, and death have been observed in rabbits, especially young and small ones.

It’s hard to tell from the photos. They could be scabs from bites (another rabbit). Or they could be keratinized papillomas.

Wick makes a good point about the possibility of mites. Although ear mites usually start out inside the ear and crusts form outward after the infestation progresses, I wouldn’t dismiss this. It could be an atypical case.

Those medications are safe for use in rabbits. I’m usually OK with a vet flipping a bunny if needed to do medical procedures (vs. some people just carrying their rabbit around like “a baby”). There are ways to hold them not completely flipped to do those things, but some bunnies struggle a lot.

All of that said though, if you didn’t have a great experience and you have other options, you could get a second opinion.

Sorry I think you missed a word in a sentence. Did the vet say they ruled out mites? or ruled out a fungal infection or syphillis? Or decided it could be fungal?  Rabbits can get syphilis from their mothers when they are born, but it usually doesn’t appear on the ears (it typically is on the mouth in those cases).

You can’t 100% rule out syphilis without a blood test, ‘technically’. But it’s not like vets need to do confirmatory tests for every possibility.. that’d really increase the bill prices! But yes, highlighting what Dana mentions, syphilis on just ears is not common at all, but I wanted to mention it -just in case- since there have been weird locations of syphilis crusting at times.

Trimethoprim Sulfa is safe to use and it is an antibiotic. Not 100% sure what the vet is trying to address using it, but it likely cannot hurt to try an antibiotic (unless you are noticing adverse effects from it).

It is good that tape worms were found and are being treated for.

I’m going to guess that the vet ruled it a possible yeast/fungal infection. Trimethoprim Sulfa does have anti-fungal properties. However, I’m not sure why they wouldn’t prescribe a skin cream.