Seizures are due to abnormal electrical activity within the brain. Causes for this abnormal activity include those that are extracranial (diseases of the body secondarily affecting the brain) and intracranial (primary diseases of the brain). Some extracranial causes include hypothyroidism, toxins, high or low red blood cell levels, low blood sugar levels and electrolyte problems. Intracranial causes can include infection, inflammation, strokes and tumours.

One of the most common causes of seizures in dogs is idiopathic epilepsy, meaning an underlying cause cannot be identified. This typically occurs in animals between the ages of six months and five years.

Clinical signs

Common signs of seizures are loss of consciousness, paddling of the limbs, stiffness of the limbs, urination and defecation, although this list is not inclusive; other signs such as focal areas of twitching and behavioural changes are possible. Some owners will notice their pet acting abnormally before or after a seizure. These periods are known as the pre-ictal and post-ictal phases, respectively. Animals may be aggressive, fearful, confused or blind in the post-ictal phase and this may last for several days.


Treatment for seizures involves attempting to identify (through bloodwork, abdominal ultrasounds, MRI, spinal taps, etc) and treat any underlying causes. The seizures themselves are managed with anti-epileptic medications, of which several are available. It is important to understand that in most cases the seizures are never cured, but we hope to reduce the severity and frequency of the events.