Idiopathic Epilepsy in Dogs


  • Idiopathic epilepsy is the most common cause of repeated seizures in dogs.
  • Dogs with idiopathic epilepsy tend to start having seizures between six months and six years old, and appear perfectly normal between episodes.
  • Although it’s not a fully understood condition, idiopathic epilepsy has been proven to be genetic in many breeds.
  • Idiopathic epilepsy is a lifelong condition that can’t be cured but, in most cases, it can be well managed with medication allowing affected dogs to live a good quality of life.
  • It’s important to have your dog checked by your vet if they have a seizure, even if they have recovered well.
  • Read more about other causes of seizures in dogs.

What is idiopathic epilepsy?

A close up photo of a dog lying on the floor
  • Idiopathic epilepsy is a common cause of recurrent seizures in dogs.
  • It tends to start causing seizures between six months and six years old and is a lifelong condition.
  • Some dogs with idiopathic epilepsy have several seizures a day, whereas others have a lot less (perhaps one every few months or even years). Most dogs appear completely fine between episodes.
  • Vets don’t yet fully understand the cause of idiopathic epilepsy in every dog, but it’s been proven to be a genetic problem (passed from parent to puppy) in many breeds.

Breeds prone to idiopathic epilepsy

Idiopathic epilepsy affects approximately one in every 200 dogs across the UK and although it can affect any breed, it’s most common in the following:


Idiopathic epilepsy tends to cause seizures that last between one and three minutes. Some dogs have several seizures per day, whereas others have a lot less, (perhaps one every few months or years). Most dogs with idiopathic epilepsy have no other symptoms and are perfectly well between seizures.

Before the seizure

Epileptic seizures are most common during rest and sleep but other triggers might include stress, excitement, hot weather, a change in routine or sleeping patterns, or hormonal changes. You might notice your dog showing some of the following signs a few seconds to an hour beforehand:

  • Restlessness
  • Tremors
  • Weeing
  • Barking
  • Salivating
  • Staring into the distance

During the seizure

Most dogs with idiopathic epilepsy have ‘generalised’ (full-body) seizures. During a generalised seizure, dogs tend to fall over, lose consciousness, thrash their legs, drool/foam at the mouth, and pee/poo.

However, some dogs with idiopathic epilepsy have ‘focal’ (partial) seizures which only affect part of their brain, and cause milder symptoms such as twitching in the face or leg. Whatever type of seizure your dog has, it can be very unpleasant to witness but fortunately your dog is likely to be completely unaware of what’s happening — stay calm and follow our first aid advice.

After the seizure

Most dogs return to normal within a few minutes of having a seizure but some can take as long as a couple of days (although this is rare). Within this time you may notice that your dog is a little confused, unsteady on their feet, low in energy, and less interested in food. It’s very important to contact your vet for advice after your dog has had a seizure.

When to contact your vet

  • It’s important to contact your vet for advice if your dog has a seizure, even if they seem fine afterwards or have already been prescribed anti-epileptic drugs.
  • You should contact your vet immediately if your dog has had more than one seizure in the last 24 hours, or has been seizuring for more than two minutes.


Idiopathic epilepsy doesn’t cause any changes that can be picked up on tests so is usually diagnosed by ruling out other causes.

  • Your vet will examine your dog and ask you some questions.
  • They will take into account their age — idiopathic epilepsy tends to cause seizures in dogs aged six months to six years old.
  • They may want to run some blood and urine tests to check for anything abnormal.
  • If nothing abnormal is detected, your dog has no other symptoms, and they are in the right age bracket idiopathic epilepsy is the most likely cause — at this point your vet may want to try some treatment.
  • If your vet is concerned that your dog’s seizures could be caused by something else, they may suggest referring them for an MRI brain scan. Read about the other causes of seizures in dogs.


Treatment helps most dogs with idiopathic epilepsy have fewer seizures and maintain a good quality of life. Anti-epileptic drugs, specialised diets and trigger avoidance can all help.

Anti-epileptic drugs

  • There are a few different anti-epileptic drugs (AEDs) that can help control seizures in dogs. They work by stabilising electrical activity in the brain which reduces the chance of a seizure happening. One example is phenobarbital.
  • Most dogs don’t stop having seizures completely with AEDs but they tend to be a lot less frequent and severe.
  • AEDs can cause significant side effects, so are only recommended if a dog’s seizures are severe and frequent enough to be affecting their quality of life. Your vet is likely to suggest starting them if your dog has:
    • More than two seizures in six months
    • A seizure that lasts more than five minutes
    • Seizures that cause severe side effects such as blindness or aggression for more than 24 hours afterwards.
  • Treatment with AEDs is considered successful if they allow a good quality of life by reducing seizures whilst not causing too many side effects.
  • It’s likely that your dog will be started on a low dose and have it increased as necessary. If your dog’s seizures are hard to control it may be necessary to combine two or three different AEDs.
  • AEDs must be given every day, at approximately the same time to keep blood levels consistent. It’s also important to give them with or without food as per the instructions.
  • It’s likely that your dog will need AEDs for life and it’s very important never to stop them suddenly as this can cause withdrawal seizures.
  • You will need to keep a seizure diary and take your dog to the vet for regular check-ups.

A specialist diet — there is evidence to show that a diet enriched with medium chain triglycerides (MCT), can help some dogs suffering with seizures caused by idiopathic epilepsy. Speak to your vet for more information. 

Trigger avoidance — if you know of anything that triggers your dog’s seizures, such as loud noises, bright lights, or busy/stressful environments, avoid these wherever possible.

Monitoring and check-ups

Dogs taking anti-epileptic medication need regular check-ups with the vet to make sure:

  • Their seizures are well-controlled.
  • Their drug dose is still correct.
  • Any side effects are manageable.

They may need regular blood tests and, if your dog isn’t responding as expected, they may need further investigations such as an MRI brain scan.

Status epilepticus

Any seizure that lasts for more than five minutes (known as status epilepticus) can cause permanent damage to the brain and other vital organs, so if your dog has been seizing for more than two minutes we advise calling your vet immediately. It’s likely that they will advise bringing your dog to the surgery for emergency treatment, which might include:

  • A combination of anti-epileptic drugs given directly into the bloodstream to stop the seizure. If this isn’t successful your dog may need to be put under an anaesthetic to control their seizure.
  • An overnight stay once the seizure is controlled so your vet can monitor them and stop any further seizures straight away.
  • A fluid drip to keep them hydrated while they recover.
  • Some investigations to find out what caused their seizure (unless the cause is known).
  • Very sadly, some dogs never recover from status epilepticus and, if your dog continues seizing despite medication, you may need to consider euthanasia (putting them to sleep).


Most dogs with idiopathic epilepsy can be well controlled with medication — it might not be possible to stop their seizures completely, but they can usually be reduced to a level that enables a very good quality of life.

Sadly, there are a small number of dogs that don’t respond to medication. If this is the case for your dog, and their seizures are affecting their quality of life, it may be necessary to consider euthanasia (putting them to sleep).


There is nothing you can do to prevent your dog from developing idiopathic epilepsy but you can prevent them passing it on by not breeding them. If you are thinking of getting a puppy, you should ask the breeder about the health of the parents and any previous litters.


Treatment for a dog with idiopathic epilepsy can become very expensive, especially if they need hospitalisation, investigations and long-term antiepileptic drugs. It’s important to speak openly to your vet about your finances, the cost of treatment, as well as what you think is right for your dog. There is often more than one treatment option so if one doesn’t work for you and your pet then your vet may be able to offer another.

Consider insuring your dog as soon as you get them, before any signs of illness start, to ensure you have all the support you need to care for them.


Can I wean my dog off anti-epileptic drugs?

If your dog hasn’t had a seizure in a very long time (one-two years), it may be possible to slowly wean them off their anti-epileptic medication. However, you should only ever try this under the close supervision of your vet, who will help you reduce the dose as safely as possible and monitor your dog throughout. Weaning your dog off their anti-epileptic medication always comes with the risk that their seizures might start again and, if this does happen, it’s important to be aware that they can be harder to control again afterwards.

How can I tell if my dog’s had a seizure when I’m not there?

Your dog may not show any signs of having had a seizure, but you might notice they are a little confused, unsteady on their feet, low in energy, and/or less interested in food.  There might also be signs around the house such as your dog toileting indoors, saliva, or signs of your dog thrashing. You could also set up a camera to monitor your dog remotely.

Does epilepsy make dogs behave differently?

Evidence suggests that idiopathic epilepsy in dogs might be linked to behavioural changes such as higher levels of anxiety and lower attention. If you are concerned about your dog please contact your vet for advice. 

Can my dog swallow their tongue during a seizure?

No, it is actually impossible for a dog to swallow their tongue as it is firmly attached to the bottom of their mouth. They can unfortunately bite their own tongue during a seizure. However, it is important not to put your hand near your dog’s mouth during a seizure to try and move the tongue, as you may get bitten by accident.

Is epilepsy contagious?

No, idiopathic epilepsy isn’t contagious, although it can be genetic (passed down from parents). Other causes of seizures might be infectious — check out our page on seizures for more information.

Published: April 2023

Written by vets and vet nurses. This advice is for UK pets only. Illustrations by Samantha Elmhurst.