My 3 1/2 year old Hav Charlie woke up this morning, made on our carpet right in front of us, which seemed odd and proceeded to have a seizure out of the blue. This NEVER happened before and , needless to say, we were terrified. He was flailing and stiff when I went to pick him up. He was shaken up afterwards, but now he's fine. What could have caused this? Has anyone else experienced this? I took him to the vet and his reflexes and coordination are fine. They are running bloodwork to check for anything obvious. If anyone has experience with this I would appreciate any information that you have.