Dear Daisy Dog
Stanley, our 2-year-old beagle, had a single short seizure. His physical exam and blood tests were normal, so our veterinarian isn’t very concerned. What causes seizures?
Seizures result from an electrical disturbance in hyper-excitable nerves in the brain.
The most common cause in dogs is idiopathic epilepsy, which means an underlying cause of the dog’s repeated seizures cannot be identified. Epilepsy, which is inherited in beagles and certain other purebred and mixed-breed dogs, generally manifests between one and four years of age.
Liver problems, including an abnormal blood circulation pattern that bypasses the liver, also can trigger seizures. When the liver isn’t working properly or blood goes around instead of through it, the organ can’t detoxify the blood, so ammonia and other metabolic poisons can reach the brain.
Toxins, such as lead, chocolate and some insecticides, can cause seizures.
Extremely low blood sugar induces seizures, because the brain requires sugar, or glucose, for energy. Severe hypoglycemia can result from excessive insulin, either injected into a diabetic patient or secreted by a pancreatic tumor.
Abnormal levels of electrolytes, including sodium, potassium and calcium, also may initiate seizures.
Other causes of seizures include infectious and non-infectious encephalitis, brain tumors, head trauma, and bleeding into the brain, for example, from ingestion of rat poison.
Some fortunate dogs have only one seizure. But if Stanley does have another, you should record the details in a seizure diary and contact your veterinarian for advice. Fortunately, medication is very effective at limiting the frequency and severity of seizures.