
Try not to be too alarmed ;-) Epilepsy is often a broadly used term for seizures (fits) that don't have an obviously specific cause. If fitting is regular or clustered (lots of them in quick succession) then generally the cause would be idiopathic epilepsy if something else had not shown up in tests - and as this has so far only happened once to your youngster that is a big assumption to make, so try to think happy thoughts!!! ;-)
Seizures can be caused by a variety of factors so just keep an eye on him and record any changes that you see in his behaviour, health etc so that you can give your vet a detailed report if necessary.
If you have contact details for your dog's breeder, phone him/her and describe what's happened. There may be a mode of inheritance but they may also be able to set your mind at rest that there isn't :-) :-) :-)
For your own peace of mind, try and ensure that when he is being left alone he is in a small and restricted area - ideally a crate or play pen. That way, should he have another *episode* he is unlikely to be able to harm himself.
Teri :-)