A seizure or convulsion is a sudden excessive firing of nerves in the brain. It results in a series of involuntary contractions of the voluntary muscles, abnormal sensations, abnormal behaviors, or some combination of these events. A seizure can last from seconds to minutes.
Seizures can occur for a variety of reasons including Low blood glucose (sugar)
Liver disease (called "hepatic encephalopathy")
Inflammatory or infectious diseases that affect the nervous system
Poisons or toxins
Blood vessel disorders that affect circulation to the brain
Always call or see your veterinarian if you witness your dog having a seizure.
For more information, please read Seizure Disorders in Dogs.