Yes my aunt had a dog with epilepsy.
Once a month he would have 2-3 siezures all within the span of 2-3 days. It was sad if you ever saw it happen, and even if you didn't witness it you would have to clean up a TON of piss (they lose control of the bladder during a siezure, much like people do).
He lived a long, happy, and healthy life though.
His siezures seemed to coincide with the cycles of the moon if you can believe that! He was on medication for them but it never eliminated the completely.