If we knew - if only if we knew - I have a wonderful vet who is also epileptic but he does not why. He just is and at the moment is seizure-free. But he does not know why or for how long. Just as I do not know when my beloved Pereg will have another seizure. And why her seizures are so violent when other epi dogs have clusters which would kill Pereg. We do not know as there is no rule of thumb. What we do know is that epilepsy is carried on in certain breeds and will come up time after time in those breeds. You do not need to take my word for it. Just look at the health problems on ome of the breeds on Breedia.