Piper is a 3 yr old Dutch. He has episodes, for lack of a better term, about once a month on average. The episodes come on without warning signs. During an episode, Piper bends his body to the left and holds with tense muscles for 5-10 seconds. Then he does it to the right. He draws up his limbs in flexion and rolls onto his side or back. The process repeats several times and then he relaxes after a couple of minutes of the acute phase. He lays still, apparently relaxed for a minute or two and then he gets up and hops across the room as though nothing happened. Then he's fine the rest of the day. Diet consists of Timothy hay, orchard grass, oxbow adult rabbit food (pellets) Italian parsley, kale and small amounts of steel cut oatmeal. I'm trying to figure out what is causing these episodes. Vet hasn't been able to help much, except to confirm that he's got nothing abnormal on exam. Any ideas? Thanks.