Hi Ali, we've had/have 3 BC's over the last 14 years with seizures. All had seizures attributed to thyroid problems and with thyroxin the seizures have stopped.
A thyroid panel blood test is easy to have done.
Some info: https://www.dogster.com/lifestyle/we-interview-dr-jean-dodds-expert-dog-thyroid-issues
A good source of more info: http://www.canine-epilepsy-guardian-angels.com/.
Dr Dodds is a savior for our 14 year old. Our vet dismissed the seizures, Dr Dodds, on vacation in Italy, responded imediately and put Pepper on thyroid
meds, 13 years ago and she hasn't had a seizure since.
Good luck. Hope this helps