Seizures are always scary to see in a dog and I am sorry you and Jocu are dealing with this. Were his seizures full grand mals or what are called focal or partial seizures? Does he bounce back fast after each seizure with basically no vivible postictal state? Treatment medications may be different depending on the severity/type of the seizures.
I have had 4 dogs in the past with seizures...Yoda's started when he was just over a year old and were full grand mals. Mickey's were partial seizures, not sure when the started as we adopted him out of a shelter when he was around 6 years old and no medical history came with him. Then our Kinnon developed seizures when he was 14... they were due to a brain tumor...our Sunshine at 13 years old also had seizures in just the last week of her life...also brain tumor.
If Jocu is showing no other physical/movement/mental changes then it is VERY doubtful that a brain tumor is the cause...and an MRI would be the only way to dx a brain tumor. Could he have ingested something that caused these seizures...it is strange that they would suddenly appear at his age and repeat 3x in less than 24 hours. What tests were run that you are awaiting results from?
Trini