Tooth purring sounds like they are chewing, basically, just grinding their teeth a bit. Pain grinding is a harsher grind, that comes with seemingly no reason and is usually accompanied by the rabbit seeming uncomfortable. For example, Stickers when she gets an upset tummy will be tense and lay in odd positions and let me touch her more than she usually would, while tooth grinding because she’s in pain. Whereas Powder when he’s tooth purring will sit there with his eyes half closed “purring” at me for petting him and look very relaxed.

Rufus purring generally goes in little sets of three so it’ll be silent for a while and then I’ll hit a good spot and he’ll make three little tooth rubbing noises then a pause then three more. It’s really hard to describe! Sometimes I can hardly hear it but I see his jaw moving in the little three pattern.

My understanding is that tooth grinding is generally much louder and more continuous – someone else will be better to jump in here.

I rely on context most of all though. Occassionally Rufus starts chattering his teeth together really loudly and continuously for ten seconds or so. I freaked out and thought that maybe he was hurt somewhere but he had his eyes half-closed, made no attempt to move and he was purring normally on either side of the loud run. It also didn’t seem to be when I was patting him in any one place in particular. Now I’ve come to the conclusion that it’s when he’s particularly blissed out and cosy, normal purring isn’t enough!

Tooth purring is a gentle, chewing sound that tends to be done in waves “purr purr purr…pause… purr purr….pause”. Grinding is a loud, chatter that is more constant.

Do a YouTube search for “bunny tooth purr” and you should be able to find some vids.