
It is a fairly common problem in all dogs regardless of breed or type. It is only considered a breed problem if the incidence in the breed is higher than in the general canine population.
So may things can cause epilepsy/fits that other than family history it is difficult to determine if it is a primary condition.
One is Thyroid dysfunction, trauma, lack of oxygen causing damage at whelping, blows to the head, poisoning etc etc.
I am so sorry Trevor. Has some obscure environmental cause been excluded?
Someone in our breed has had nearly all their dogs die young of an uncommon cancer, some have been unrelated, and others have been direct descendants of a brother and sister both living to 16 plus, I believe the sister is still alive with them at 17.