Epilepsy in Dogs

Epilepsy is a brain disorder characterized by recurrent seizures without a known cause, brain injury or disease. In other words, while the brain seems, for all intents and purposes, to be normal, it functions abnormally.

And although the precise cause of epilepsy remains a mystery, a genetic basis is relatively common in many breeds, including golden retrievers and golden mixes. They typically develop symptoms between the ages of 6 months and 6 years, with a median age of 2.5 years.

Seizures are either generalized or focal. Generalized seizures are more common and involve both sides of the brain, whereas focal seizures involve a smaller region on only one side of the brain. A focal seizure may be subtler, making it harder to identify. For example, some dogs may display “fly biting” behavior, appearing to catch a non-existent fly, which may be due to a focal seizure or other causes.

Signs of a generalized seizure include: loss of consciousness, convulsions characterized by stiffening (tonic) and paddling (clonic) movements, excessive drooling, unusual vocalization and involuntary urination or defecation. Signs of a focal seizure include: abnormal repetitive, uncontrollable movements in one set of muscles or a group of muscles in the body, increased salivation, dilated pupils and loss of consciousness or not.

Seizures can last from a few seconds to a few minutes, on average about 30 – 90 seconds, and the dog is typically unaware of his surroundings during this period. In some rare cases, the seizures either won’t stop or will be prolonged, which is referred to as status epilepticus.

Seizures are often characterized by three phases:

Pre-ictal phase: subtle behavioral changes such as restlessness or anxiety, which may or may not be noticeable, preceding a seizure.

Ictal phase: the seizure itself, often lasting from seconds to minutes.

Post-ictal phase: a recovery period in which the brain is “resetting” itself after this abnormal activity, characterized by confusion, disorientation and lethargy. Some dogs may even show a craving for food during this period.

When a seizure occurs, remain calm and keep your dog safe, away from furniture, stairs and water.

Do not put your hands near your dog’s mouth: dogs do NOT swallow their tongues.

Cushion your dog’s head: use a pillow or a cushion to protect your dog’s head from any injury.

Time the seizure: an active seizure lasting more than five minutes (status epilepticus) or multiple seizures in a 24-hour period (cluster seizures) is considered a medical emergency and you should take your dog to the nearest emergency veterinarian immediately.

However, you should ALWAYS see your veterinarian after your dog’s first seizure. Why? Epilepsy is a diagnosis of exclusion. A diagnosis of epilepsy is made once all other causes have been ruled out. A thorough medical history is taken and a physical examination is performed, followed by diagnostic testing such as blood and urine tests and x-rays. Additional tests such as bile acids, cerebrospinal fluid (CSF) testing, computed tomography (CT) or magnetic resonance imaging (MRI) may be recommended, depending on the initial test results. In many cases, a cause isn’t found: the term for this is idiopathic. Many epilepsy cases are classified as idiopathic since more advanced testing is often not done due either to cost or availability. A dog’s age when the seizures first start is also a prevalent factor in reaching a conclusive diagnosis.

Anticonvulsants (anti-seizure medications) are the treatment of choice for epilepsy. Once treatment has been started, it will likely be continued for the rest of your dog’s life. Stopping these medications suddenly can cause seizures. (You will have to record the date, time, length and severity of all epileptic episodes in order to determine the need for medication and your dog’s response to the treatment). If your dog’s seizures occur more than once a month or in clusters, vets often prescribe such medications as:

Phenobarbital: a long-used, effective and often inexpensive option.

Levetiracetam (Keppra®): another common, effective and fast-acting option.

Potassium Bromide: (Kbr) or Zonisamide are often used in combination with other drugs such as gabapentin or clonazepam in some dogs whose seizures are difficult to control.

Blood monitoring tests are done at specified intervals (from weeks to months) for phenobarbital and potassium bromide. These tests help determine the correct dosing levels and check organ function since these medications may have dangerous side effects. Your veterinarian will determine the proper treatment plan for your dog’s condition. Irregular dosing schedules (including starting and then stopping the medication or forgetting to give pills causing blood levels to fluctuate) may predispose your dog to more frequent or more violent seizures, so it is essenial that you remain consistent.

Most dogs do well on anti-seizure medication, allowing them to resume a normal lifestyle, although some continue to experience periodic break-through seizures. Many dogs require occasional medication adjustments and others require the addition of other medications over time.

According to the Veterinary Health Center, University of Missouri, dogs suffering from idiopathic epilepsy often have a normal or near-normal life expectancy if their seizures are well managed with medication. While some studies show a median lifespan of 8 -11 years or even up to 13.5 years, severe, poorly controlled epilepsy or cluster seizures can significantly reduce these dogs’ lifespans.

Researched and written by Nomi Berger
(main sources: VCA Canada and Veterinary Health Center,
University of Missouri)