Seizures and Epilepsy in Dogs
- A seizure is abnormal electrical activity in the brain that causes uncontrolled body movements. Epilepsy is a term to describe recurring seizures.
- Most seizures cause full-body convulsions (shakes), but some cause milder symptoms such as twitching in one part of the body.
- Seizures in dogs can be caused by a number of things including head trauma, heatstroke, low blood sugar, a brain bleed, a brain tumour, toxins, and a common condition called ‘idiopathic epilepsy’.
- It’s important to have your dog checked by your vet if they have a seizure, even if they have recovered well.
What does a seizure look like?
Most seizures in dogs are full-body seizures. This type of seizure is called a generalised seizure and tends to cause uncontrolled movements across the whole body. This can include:
- Loss of consciousness
- Jerking movements
- Paddling legs
- Tense/cramped muscles
- Eyes rolling back or moving side to side
- Drooling/frothing at the mouth
- Peeing and pooing
Some seizures only affect part of the body and cause much milder symptoms, such as twitching in the face or leg. These are called focal or partial seizures and are much rarer than generalised seizures.
There is also a very rare type of seizure called an ‘absence seizure’ that causes dogs to lose awareness of their surroundings, become vacant, stare into the distance and stop responding when they are spoken to.
Most seizures tend to last a few seconds to a couple of minutes. If a seizure lasts for more than five minutes (we call this ‘status epilepticus’) it has the potential to cause permanent brain damage. Read more about status epilepticus below.
What causes seizures in dogs
There are many different things that can cause seizures in dogs including:
- Idiopathic epilepsy is the most common cause of seizures in dogs between six months and six years old.
- It’s known to be genetic (passed from parent to puppies) in several breeds of dogs.
- The cause of idiopathic epilepsy is unknown.
- Toxins such as caffeine, chocolate, rat poison and slug bait can all cause seizures.
- Severe head injuries can cause seizures.
- Seizures are common in severe cases of heatstroke.
Hypoglycaemia (low blood sugar)
- If blood sugar drops very low, it can cause seizures.
- This is very rare in fit healthy dogs and mostly affects diabetic dogs and young puppies that have gone without food for a long time.
- One of the functions of the liver is to remove toxins from the blood. If it isn’t functioning properly, these toxins can build up and cause seizures.
- This is most common in older dogs with severe liver disease and very young puppies born with a condition called a ‘portosystemic shunt’.
- Bacterial and viral infections can cause seizures if they affect the brain.
- Lungworm is a common parasite of dogs in the UK which can cause seizures if it enters the brain.
- Brain tumours are rare but can cause seizures in dogs.
- If your dog is under six years old, a brain tumour is very unlikely to be the cause of their seizures.
Hypocalcaemia (low calcium)
- If blood calcium levels drop too low it can cause seizures.
- This is most common in female dogs after giving birth or while they are lactating.
How will my vet know what caused my dog’s seizure?
Your vet will examine your dog and ask some questions about their history and symptoms including how often the seizures are happening and what your dog was doing just before the seizure. If you are able to take a video of your dog having a seizure and their recovery, this can help your vet.
- If your dog has only had a single seizure, it may not need investigating straight away. As long as the seizure lasted less than five minutes, your dog recovered well afterwards and they appear healthy at their check-up, your vet will probably suggest monitoring them at home and only running some investigations if they have another. The seizure may have just been a one-off – many dogs have an unexplained seizure in their lifetime.
- If it wasn’t your dog’s first seizure, it lasted more than five minutes, they seem otherwise unwell or they are less than six months or older than six years old, it’s likely that your vet will suggest further investigations. Your vet will probably run some blood and urine tests, then depending on what’s found, your dog’s age, and other symptoms, they might recommend referral to a specialist for more in-depth investigations such as a brain scan.
- If your vet is suspicious that your dog is suffering from idiopathic epilepsy they might suggest trialling some anti-epileptic drugs before running any in-depth investigations. Check out our page on idiopathic epilepsy for more detailed information about the condition.
How are seizures treated?
If your dog has only had a single seizure, it won’t be necessary to start any treatment straight away because they might never have another. However, if your dog is having regular seizures that are affecting their quality of life, your vet may suggest starting some treatment to control them. This could include:
- Treating the cause – if a cause for seizures has been found your vet will suggest appropriate treatment.
- Anti-epileptic drugs (AEDs) – anti-epileptic drugs (anticonvulsants) work by reducing the severity and frequency of seizures. Some dogs stop having seizures completely while taking AEDs, but most continue to have the occasional seizure while taking them. These medications can cause side effects if given over a long period so should only be started if a dog’s seizures start affecting their quality of life. Once your dog has started AEDs, they will most likely need to stay on them for life and need regular check-ups and blood tests.
- A specialist diet – there is evidence to show that a diet enriched with medium chain triglycerides (MCT), can help dogs suffering with seizures caused by idiopathic epilepsy. For more information, check out our page on idiopathic epilepsy in dogs.
- Avoid triggers – if you know of anything that triggers your dog’s seizures, such as loud noises, bright lights, or busy/stressful environments, then you should avoid these wherever possible.
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 anaesthetic to control their seizure.
- An overnight stay once the seizure is controlled so your vet can monitor your dog 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 already 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).
If your dog has a history of seizures, it’s important to keep a seizure diary. Make a note of:
- When the seizure happened.
- How long it lasted.
- What it looked like (Did they wee or poo? Was their whole body shaking or did it just affect part of them? How long did it take them to come round?) If you are able, you can video the seizure.
Contact your vet for advice if your dog’s seizures start to become more regular, last longer, or their symptoms become more severe.
When to contact your vet
- If your dog is having a seizure right now, follow our first aid advice.
- Contact your vet once they have started to come round, or if the seizure lasts for longer than two minutes.
- Do not transport your dog during a seizure unless your vet specifically tells you to.
- If your dog is on anti-epileptic drugs but still having regular seizures, keep a seizure diary and contact your vet for advice.
Treatment for seizures can become very expensive, especially if your dog needs to be hospitalised and/or requires ongoing medication. It’s important to speak openly to your vet about the cost of treatment, your finances and what you think is right for your dog. If one treatment option isn’t possible, your vet may be able to offer you another.
Consider insuring your dog as soon as you get them, before any signs of illness start. This will ensure you have all the support you need to care for them.
My dog has stopped having seizures, can I stop their anti-epileptic medication?
If your dog has been seizure-free for more than a year, it may be possible for your vet to very slowly reduce their medication to see if they can cope without it. However the risk of them having another seizure is high, and it might be more difficult to control their seizures the second time round. Never reduce your dog’s medication dose without speaking to your vet first.
Published: April 2023
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Written by vets and vet nurses. This advice is for UK pets only. Illustrations by Samantha Elmhurst.