Strange, frightening behavior

Question
I have a 3 year old small breed Sallander rabbit, Chubbs, who has exhibited the strangest behavior. Yesterday being the third time I've seen three times since we got him 3 years ago.
He starts breathing really quickly, he shakes all over and has a hard time controlling his ability to walk or hop. He ends up sort of pushing himself on his belly with his back toes and once he gets himself propped up he doesn't move unless he feels scared. He will let us hold him, he doesn't mind being petted, but he won't eat and he only gets into his toilet if absolutely necessary. His head doesn't tilt but unless he is laying flat on his belly he rocks from side to side like looking like a drunk.
The thing that is stranger still is it only lasts 12 to 18 hours (starting mid morning/ early afternoon) and then the next day he is fine. It always seems to happen on a weekend when we can't get him to a vet (I live in Norway and things are run a bit differently here then in the US.) When we take him the vet can't find a thing wrong. He has done everything short of a ct-scan.
I wonder if it could be something that he is ingesting from the veggies we are giving him or perhaps a seizure or maybe a stroke? Our other rabbit, a small breed Palomino, shows no problems despite them always eating the same things.
I was wondering if you had any ideas about what it could be? I know it is hard without seeing it.
Thanks so much, Jennifer

Answer
Dear Jennifer,

I've been thinking about this one for days, and the only thing I can come up with is that the bunny is suffering from painful gas that makes him want to stretch out and then not move.  Rabbits prone to gas can behave this way, and it's very important to relieve the pain with (1) pediatric simethicone suspension (about 1/2cc) and (2) gentle tummy massage, preferably with a vibrating massager.  Some rabbits can react so badly to gas pain that they actually go into shock and start becoming hypothermic.  So it might be a good idea to check your bunny's body temperature if this happens again.  Please see:

www.bio.miami.edu/hare/sickbun.html

If this were a stroke, you would likely see unilateral signs of paralysis/paresis or palsy.  It could be a "seizure", but that's sort of a non-specific term that could apply to many different things.

I'm guessing gas/GI problems.  If this is the case, then I strongly urge you to read:

www.bio.miami.edu/hare/ileus.html

and

www.bio.miami.edu/hare/poop.html

The most common reasons that trigger episodes of gas/ileus are incorrect diet:

www.bio.miami.edu/hare/diet.html

and/or

dental problems, such as molar spurs

www.bio.miami.edu/hare/dental.html

I hope this helps.

Dana