Epilepsy in dogs

Based on the international veterinary neurology guidelines (IVETF, ACVIM). Updated 19 October 2026. 10 min read.

What is epilepsy in dogs?

Epilepsy is a brain disorder in which the brain has a lasting tendency to produce epileptic seizures. A seizure happens when a group of neurons (the nerve cells in the brain) fire electrically, excessively and all at once, like a brief “electrical storm”. The seizure usually stops on its own, but it can happen again.

The difference between a seizure and epilepsy matters. A dog can have a seizure because of a problem outside the brain, such as a sudden drop in blood sugar or a poisoning. That is a reactive seizure, and the brain itself is healthy. According to the International Veterinary Epilepsy Task Force (IVETF), a dog has epilepsy when it has had at least two unprovoked seizures more than 24 hours apart.

Epilepsy is the most common chronic neurological disease in dogs. In the general dog population it is estimated to affect roughly 0.6-0.75% of dogs, and in some breeds the figure is much higher.

What does an epileptic seizure look like in a dog?

The best-known form is the generalised seizure: the dog suddenly falls onto its side, loses consciousness, goes stiff and then makes rhythmic paddling movements with its legs. It may drool heavily, foam at the mouth, and pass urine or faeces. A seizure like this usually lasts less than 5 minutes, most often 1-2 minutes.

Many seizures look nothing like this. A seizure can be limited to one part of the body: twitching of the face or an eyelid, chewing movements with nothing in the mouth, a leg that trembles rhythmically, sudden drooling, dilated pupils, or a short episode in which the dog seems frightened, hides or looks for its owner for no reason. These are called focal seizures. I explain them in detail, with examples, in the article on types of epileptic seizures.

What happens before and after a seizure

Some dogs change hours or even days before a seizure: they are restless, unsettled and want to be close to their owner. This period is called the prodrome. After the seizure comes the post-ictal phase, the time the brain needs to recover. The dog may be disorientated, bump into things, seem unable to see, walk unsteadily, or drink or eat a lot. The post-ictal phase can last from a few minutes to a few hours, and occasionally even days.

Does one seizure mean my dog has epilepsy?

Not necessarily. A single seizure is not epilepsy, but it is always a reason to see a vet, as soon as possible once your dog has recovered. A first seizure needs investigating because it may be the sign of a problem that is treated differently: liver disease, low blood sugar, a poisoning or a lesion in the brain.

If the episode happens again, bring the video recording and your notes on each seizure to the consultation. Sometimes what looks like a seizure is actually fainting caused by the heart, or a balance problem. The differences are explained in the article on epileptic seizures and fainting.

What causes epilepsy in dogs?

The IVETF guidelines divide seizures into three broad groups according to their cause. The group matters because it determines the treatment and the outlook.

Idiopathic epilepsy is the most common form in dogs. It is a diagnosis of exclusion: the vet has to rule out the other causes before calling it idiopathic. The causes are covered in detail in the article on causes of epileptic seizures and diagnosis.

At what age does epilepsy start in dogs, and which breeds are predisposed?

Idiopathic epilepsy usually starts between 6 months and 6 years of age. If the first seizures appear in a puppy under 6 months or in a dog over 6 years, a structural or metabolic cause becomes more likely, and the guidelines recommend more thorough investigation, including an MRI.

Any dog can develop epilepsy, crossbreeds included. In some breeds, however, studies have shown a higher frequency and a probable inherited component. These include the Belgian Shepherd, Border Collie, Australian Shepherd, Labrador Retriever, Golden Retriever, Bernese Mountain Dog, Border Terrier, Dalmatian, English Springer Spaniel, Standard Poodle, Hungarian Vizsla and Irish Wolfhound. In one Danish study, for example, idiopathic epilepsy was found in 3.1% of Labradors and in around 9.5% of Belgian Shepherds.

Is epilepsy in dogs hereditary?

In many breeds a genetic cause is suspected, but in most of them the genes involved have not yet been identified. The inheritance seems to be complex, involving several genes as well as environmental factors. The practical advice for breeders is that a dog with idiopathic epilepsy should not be bred from. You will find more detail in the article on breeds predisposed to epilepsy.

How is epilepsy diagnosed in dogs?

The diagnosis is built up step by step, because there is no single test that shows “epilepsy”. The IVETF diagnostic guideline describes three levels of confidence, from the most basic to the most complete.

1. The history and a video of the seizure. What the episode looked like, how long it lasted, what happened before and after, and what time of day it occurred. A 30-second video often says more than any description.
2. The clinical and neurological examination. The vet checks the gait, reflexes, cranial nerves and responses to stimuli. In a dog with idiopathic epilepsy the examination is normal between seizures (except in the days after a seizure or because of the effects of medication).
3. Blood and urine tests. A full blood count, biochemistry, bile acids or ammonia (to check liver function) and a urinalysis. These look for reactive causes.
4. MRI of the brain. Magnetic resonance imaging, done under general anaesthesia, shows whether there is a lesion in the brain. It is recommended especially when the seizures start before 6 months or after 6 years of age, when the neurological examination is abnormal, after cluster seizures or status epilepticus, and when the seizures do not respond to treatment.
5. Cerebrospinal fluid (CSF) analysis. The fluid around the brain and spinal cord, usually collected under the same anaesthetic as the MRI, helps detect inflammation and infection.
6. EEG (electroencephalography). This records the electrical activity of the brain. It can confirm that the episodes are epileptic and represents the highest level of confidence in the IVETF guideline. It is not yet a routine test everywhere, but it is particularly useful when it is unclear whether the episodes are seizures at all. You will find more on the veterinary EEG page.

When should treatment for epilepsy start?

Not every dog that has had a seizure needs treatment straight away. The IVETF and ACVIM (American College of Veterinary Internal Medicine) guidelines recommend starting long-term treatment if at least one of the following applies:

• two or more seizures within 6 months;
• cluster seizures (two or more within 24 hours) or status epilepticus (a seizure lasting more than 5 minutes, or repeated seizures without recovery in between);
• severe signs after a seizure, such as aggression or temporary blindness, or a post-ictal phase lasting longer than 24 hours;
• seizures that are becoming more frequent, longer or more severe over time;
• a known lesion in the brain or a previous head injury.

If a dog has had a single short seizure, or the seizures are very infrequent, the vet may suggest monitoring alone, with a seizure diary. The decision is made together, once the vet has explained the risks of both options.

How is epilepsy in dogs treated?

Treatment is based on antiepileptic medication given every day at set times, usually for life. The vet chooses the medication, the dose and any combinations according to the type of seizures, how often they occur, the dog’s weight and general health, and any other conditions. The dose is adjusted over time, based on the response and on blood tests.

Why regular blood tests are needed

For many antiepileptic drugs the level of the drug in the blood is measured, to check that the dose is both effective and safe. Biochemistry tests are also done to check the liver and other organs. For some medications, for example, the IVETF guideline recommends blood tests before treatment starts, at about 2 weeks and 3 months, and then every 6 months. The exact schedule depends on the medication chosen.

What you can do

• Give the medication at the same times each day, and do not change the dose without talking to your vet.
• Never stop the treatment suddenly. Stopping abruptly is one of the most common triggers of seizures, including status epilepticus.
• Keep a seizure diary: the date, time, how long it lasted, what it looked like, how long recovery took and what happened beforehand.
• Keep to the same food. Changes in diet, vomiting and diarrhoea can affect how the medication is absorbed.
• Tell your vet if you notice side effects. Some medications can cause drowsiness, wobbliness or increased appetite, especially in the first few weeks.

Can epilepsy in dogs be cured?

In most cases, no. Idiopathic epilepsy is controlled, not cured. The realistic aim of treatment, as the IVETF guideline puts it, is for seizures to become less frequent, shorter and milder, for cluster seizures and status epilepticus to stop, and for the side effects of the medication to be acceptable. Some dogs have no further seizures on treatment, while others continue to have occasional ones.

Remission (a long period without seizures) does occur in some dogs: in studies from university hospitals, in roughly 15-30% of dogs with idiopathic epilepsy. Even then, reducing the treatment is only discussed after at least 1-2 years without seizures, and it is done very gradually, under supervision.

In structural epilepsy the outlook depends on the cause: inflammation of the brain may respond to treatment, while a tumour follows a different course. With reactive seizures, treating the underlying cause (for example correcting the blood sugar or removing the toxin) can stop the seizures completely.

How long does a dog with epilepsy live, and what is life like?

Many dogs with well-controlled idiopathic epilepsy have a normal lifespan. The ACVIM consensus notes that, in the studies available, the average lifespan of dogs with idiopathic epilepsy was no shorter than that of dogs in general, unlike dogs with structural epilepsy. The outlook is more guarded in dogs that have cluster seizures or episodes of status epilepticus, and it varies from breed to breed.

Quality of life depends a great deal on routine. A dog with epilepsy can go for walks, play and travel. What matters is keeping your dog at its ideal weight (the increased appetite caused by some medications easily leads to weight gain), regular exercise and a steady daily routine. You will find practical tips for everyday life in the article on living with a dog with epilepsy.

When should you take your dog to a veterinary neurologist?

Your usual vet can manage many cases of epilepsy. A neurology consultation is especially helpful if:

• the first seizure happened before 6 months or after 6 years of age;
• your dog has other neurological signs between seizures (unsteady walking, a head tilt, changes in behaviour, blindness);
• there have been cluster seizures or status epilepticus;
• the seizures continue despite treatment being given correctly;
• it is unclear whether the episodes are seizures or something else.

At the epilepsy consultation I go back over the history and the videos with you, carry out a neurological examination, review the existing test results and decide which further investigations are needed and what the treatment plan will be. You can send the documents in advance by e-mail to helga@demed.ro. You will find more about how the consultation works on the epilepsy consultation page.

Frequently asked questions

This article is for information only and does not replace a veterinary consultation.