Does your bunny have dandruff? Is it located along his spine or around his neck or rear end? Does he have patches of missing fur? Could be fur mites.
There are a couple different kinds of fur mites that can be found on rabbits, and they can be diagnosed by looking at some of the dandruff or a skin scraping in mineral oil under a microscope. You might also see mite eggs attached to some of the hair shafts.
As with ear mites, have your vet prescribe a dose of Ivermectin or Revolution, taking care to get the correct dosage and application instructions. You can dust with over-the-counter flea powder, as well, but this takes longer and is much more work. Disinfect the rabbit’s area, litter box, bowls, and toys to get rid of any residual bugs, and be sure to keep healthy rabbits away from the infected one(s) until the mites are gone.