That was alot of reading to catch up on! Boy was I shocked. Sadly As a probable expert in epilepsy now (child and sibling), this looks neurological more than seizure. Simple partials wouldn’t have the dazed look but I would expect them to be pretty hard to detect in a dog (even in humans) and would typically be short if any physical signs. Everyone else was very accurate about complex partials (the loss of consciousness kind) and generalized aka
grand mal ones which these are not. I suspect you are onto something with vaccine combined with puppy neurology. Darn, I had assumed it was the ear glue early in the reading.