I also had success many years ago with a lab that was diagnosed with epilepsy. I used a holistic vet who used homeopathy. I also stopped vaccinating him. I have no idea where you are but many of the vets will do phone consultations and will work with your local vet. I have used the following with good results:

Dr. Marty Goldstein
Smith Ridge Veterinary Center
South Salem, NY

Dr. Christina (Tina) Aiken
Kilshannagh Veterinary Clinic
Ancramdale, NY

I hope you have good results no matter how you address this!

Our boy eats a " No Grain Kibble ". He gets daily supplements of Calcium, Milk Thislte, Vitamin D3, B complex and Joint supplements. When a dog is on seizure meds, it tends to deplete their calcium supply. The vitamin B complex helps his his central nervous system and the D3 is because we live in the Northwest, cloudy all the time. My vet suggested I start giving all my dogs the D3 in small doses so it's part of our daily routine.