My rabbit Mango does this too when I scratch his rear – he starts licking himself and it cracks me up. I think either he must like it or it tickles him. The vet probably would have found a tender or sore spot during her exam so I think it’s just a pleasant reaction.

As Sarita says, this is likely a happy thing…Bunnies tend to bite or box or flee if they don’t like something…They would probobly NEVER lick if you were hurting them!

Does he lick anything with your scent on it? Normally pain is masked with quiet and lethargy and/or grinding of teeth (not to be confused with the utter contentment movement of a slow chewing motion) so I don’t think that is it. He may just be content. Do you know with the broken back and all if he has all the feeling back there that other bunnies do?

When I rub the hind quarters of my bunnies or if I rub their ears, they also begin licking. I think it is a reflex for “group grooming”

Pepper has a "secret spot" behind her ears that, if you pet/scritch it, she licks.  She will lick the surface she is on, or her own front paws.

Hmm, that’s really interesting. I haven’t noticed that with my two.

Animals w/ tails…have plenty of nerve endings near the spine & or where the tail extends from the spine.  Its almost like a natural reaction, like a reflex.  You can test this from the tail up the spine to find where this reflex ends.  There is actually a name for this reflex…but I can’t remember it.  I call it the non-medical term, sweet spot.  My Phoebe cat is especially sensitive to this almost up to her neck.

your grooming him, so he’s grooming you back as if to say “yay! thanks! that’s the spot!” it’s their way of showing affection.