My bun is losing fur and has what appears to be horrible dandruff. What do??

http://imgur.com/Sygpo http://imgur.com/bGaOz http://imgur.com/O9OCB

Sorry about the terrible quality, all I have around right now is my cell phone. He is losing fur up and down his back and has copious amounts of flaking skin. I took him to the vet today because I thought he might have fur mites, but they weren't convinced that that was the case. The vet sent me home with lime-sulfur dip to spritz him with every week and told me if he doesn't improve I'll need to see a rabbit specialist.

Does anyone recognize this?