I had a mini mare several years ago that I bought and she had three seizures. Marching in place, acting blind, running into things blindly, then staggering becoming quiet and then sleepy after it was over, then was fine. It happened EWVRY time she was in season! Vet felt it was pain related, and not hereditary at all. On my vet's advice, I bred her, one time, one breeding only and had second thoughts... I had decided just to put her on Regumate as I had read it would keep her from coming into season. BUT... she took with only one breeding. She never had another seizure. Her hormones must have changed things.