Definition

A seizure, also called a convulsion, is the clinical manifestation of excessive and abnormal electrical activity in the cerebral cortex of the brain. Epilepsy refers to recurrent seizure activity, which may be acquired (such as from a brain tumor or scar tissue) or idiopathic (which means of unknown origin).

Causes of Canine Seizures

Seizures in domestic dogs can be caused by either intracranial (inside the skull) or extracranial abnormalities. Intracranial causes of seizures include genetic disorders, infection (viral, fungal or bacterial encephalitis), brain tumors, abscesses, metastatic tumors from remote regions of the body, stroke, cysts, primary epilepsy, hydrocephalus and anatomical malformations. Extracranial causes include exposure to or ingestion of toxins (antifreeze/ethylene glycol, lead, metaldehyde, strychnine or other rodent bait, insecticides/organophosphates, chocolate), heat stroke, liver disease, kidney failure, direct head trauma, canine distemper virus, sudden drop in blood sugar (hypoglycemia; common with overdose of insulin in diabetic dogs), portosystemic shunt, low blood calcium (hypocalcemia; such as from eclampsia [“milk fever”] or hypoparathyroidism) and other metabolic abnormalities.

Prevention

Since there are so many, potentially unrelated causes of canine seizures, there is no particular way to prevent them from happening. However, once diagnosed, primary epileptic seizure disorders usually can be fairly well-managed with medication. Dogs known to have seizures or that are otherwise suspected to have epilepsy should not be bred.

Special Notes

Most dogs with primary seizure disorders will require lifelong treatment. Although they are fairly common, seizures in companion dogs should be taken very seriously. Sometimes, other medical conditions cause clinical signs that mimic seizures. These should be attended to, as well. Owners who think that their dog may be having seizures should consult with their veterinarian.