lab pup started having seizures at 9-10 weeks

Question
My lab pup started having "seizures" at 9-10 weeks old.  My vet has run several blood tests and ruled out a liver shunt, we're waiting on a neospora titer and have him on an antiobiotic in the meantime.  The most curious part of these episodes is that they seem to be feeding time related at least until yesterday when he had one when we let him out in the yard to play with the kids.  Usually they occur right before eating and he has on several occasions actually crawled to his bowl and started eating during a "seizure".  The seizures consist of his legs tensing up, usually lies down on belly and legs are pulled up toward his body, shaky, but completely alert.  Episodes last about a minute usually, maybe two at most.  When it starts to ease up it ends quickly with his legs appearing to be "heavy" for a few steps and then he's perfectly normal again.  We changed his feedings from 3 times a day to every four hours and noticed a significant improvement in the number of "seizures".  Unfortunately, however, he had two yesterday and one this morning (while eating).  Yesterday, one was right after getting out of his crate from a nap and getting near time to eat.  The other as I mentioned earlier, occurred when we let him out in the yard to run with the kids.  Other than these episodes, he seems to be a perfectly normal puppy.  He's growing well and all of his examinations have been normal.  My vet is stumped and will be referring us to a specialist if the neospora comes back normal.  I've read some about exercise/excitement induced seizures and see some similarities, but it seems like a stretch to me.  I'm looking for any other ideas that anyone might have.  We do have contact with the owners of one of the siblings who is also having "seizures" but they don't pinpoint the feeding time or any other consistent trigger.  I've been unsuccessful at getting the "breeder" to admit to any problems with the parents that might help our diagnosis.  Thanks so much for any ideas!

Answer
I am afraid you have already dug in beyond what I know.  I do know seizures can be hard to diagnose.  We picked up a puppy yesterday from the dog guide school's clinic that had seizures a few weeks ago.  They are still waiting for some test results.  If they can't determine the causes and assure that it won't reoccur, the dog can't be used as a dog guide.  That is 2 top vets with every possible resource, spare no expense.