Lady had idiopathic epilepsy when I adopted her as a rescue at age four. She takes two kinds of seizure medications and they are under control.
Did they do a thyroid panel when he had bloodwork? That's not part of the routine CBC and should be done on older dogs.
Have you been giving him anything for liver support? One of Lady's seizure medications can cause liver damage so she gets Marin (milk thistle). Here's some information about it:
http://www.canine-epilepsy-guardian-...lk_thistle.htm