I have a uncle , by marrage , that when I was a kid , he would have seizure , , when I was in like my preteens , and early teens , they had his so medicated , seemed like he slept most of the time , and then he ballooned to over 300 pounds , then later , he had surgery , and better medication
he became a changed man
became very active , went back to school for nursing
but now , he's gotten up their in age , and the seizure's have returned
pretty scary thing
but anyways
I do know they make a supplement for seizures in dogs , but I'm sure every dogs different , and like most medication , I'm guessing it's trial and error
good luck