Absolutely get another opinion, and don't leave out the part about the agressive behaviour following the seizures.
I had a Weimeraner (3 yrs. at the time) who had a seizure in our yard (I thought he'd been snake-bitten). My husband, neighbor, and I got him on a blanket(he was a big dog)and rushed him off to the vet. The dog couldn't even get up, so they gurneyed him into the office. Turns out it was epilepsy, and we started him on Phenobarb right away. He never did have another seizure, but a year later had a gastric torsion and we ended up having to euthanize him. I have no idea if that was related to the meds or not......