Idiopathic epilepsy, also known as primary epilepsy, is the most common cause of seizures in dogs and many of them have a genetic basis. The age of onset in dogs is usually 1 to 6 years of age. Several breeds are commonly present with idiopathic epilepsy and these are the Labrador Retriever, German Shepherd dog, and Border Collie breeds and their cross breeds. While idiopathic epilepsy may be the most common cause of epilepsy in dogs, the diagnosis is reached by ruling out other underlying causes of seizures. Bloodwork, magnetic resonance imaging (MRI) of the brain and a cerebrospinal fluid (CSF) tap are standard tests to run to diagnose this condition. Electroencephalogram (EEG) may be recommended for the diagnostic workup in some patients. Examples of diseases to rule out by performing the diagnostic tests include structural malformations of the brain (intracranial arachnoid cysts, lissencephaly. porencephaly), metabolic diseases (e.g. liver disease, kidney disease, low blood sugar, hypothyroidism, hyperlipidemia, etc.), infection, and cancer. For some patients, infectious agent testing may also be recommended.
Because seizure disorders can become very severe and difficult to control especially in breeds predisposed to such conditions, a very close relationship with your neurologist or veterinarian is important. Keeping a journal of each seizure episode, descriptions of the event, when adjustments to medications are made, and when bloodwork is checked are all pertinent for appropriate seizure management.