; Skip to main content

Seizures in dogs and cats

By September 17, 2020 Greenbay Vet News

We all know that humans can be affected by seizures (fits) and epilepsy. Dogs and cats can be affected too, which can obviously have a big impact on their lives and that of their owners. In this article, Greenbay veterinary surgeon Jemma explains more about the condition.

What is a seizure?

A seizure occurs when there is abnormal electrical activity in the brain. It can cause changes in behaviour and mentation and abnormal or uncontrolled muscle movements.

If your pet has two or more seizures or recurrent seizures, this condition is called epilepsy.

Types of seizures

Seizures can be classed into one of two categories:

Generalised seizures – these involve both sides of the brain. Usually there is involuntary muscle movement on both sides of the body and loss of consciousness or awareness (your pet will not be able to respond to your voice). Salivation, urination and defection may also occur.

Focal seizures – these originate from only one particular area of the brain. The signs of these depend on what part of the brain is affected, but only a single side or specific part of the body are affected. Awareness may or may not be affected. You may see repetitive twitching or movements of limbs or parts of the body, e.g. facial twitching, rhythmic blinking, head shaking or behavioural signs such as restlessness, anxiety/fear or attention seeking. There may also be abnormal nerve function e.g. pupil dilation, salivation, vomiting.

A focal seizure may progress to a generalised seizure.

Generalised seizures may be further classified according to their frequency:

  • Isolated seizure – one seizure lasting less than five minutes with complete recovery afterwards. These are the most common.
  • Cluster seizures – 2 or more seizures in a 24hr period with complete recovery in-between.
  • Status epilepticus – a seizure lasting more than 5 minutes or seizures without complete recovery in-between.  Status epilepticus can result in brain damage. It is a life-threatening condition that requires urgent veterinary treatment.

Stages of a seizure

A seizure consists of three phases:

  • Pre-ictal phase (aura) – this occurs before the seizure and may last a few seconds to a few hours. During this period your pet may have altered behaviour and be restless, anxious, agitated or nervous and may hide, attention seek, shake, hypersalivate or vomit.
  • The ictal phase – this is when the seizure itself occurs and can last from a few seconds to several minutes.
  • Post-ictal phase– this is the recovery phase immediately after the seizure has occurred. Your pet may appear confused or disorientated, they may be flat and lethargic or restless and pacing and they may even appear temporarily blind. This can last from a few minutes to several hours.

What should I do if my pet is having a seizure?

A seizure can be very distressing to you and your pet, but rest assured your pet does not feel pain during a seizure and are largely unaware they are occurring. If cluster seizures or status epilepticus is occurring, you must contact us for urgent veterinary treatment.

  • You can help your pet by reducing external stimuli such as noise and light (darken the room if possible) .
  • Move surrounding objects away or place your pet on the floor to avoid them injuring themselves if you can do so safely.
  • If a seizure lasts longer than 3 minutes, your pet may overheat due to muscle contractions. You can try and help cool your pet e.g. using air conditioning, cool damp towels.

They may feel confused and disorientated afterwards so reassuring them and giving them time to recover and readjust afterwards is important. They may be left feeling exhausted, so let them rest.

What causes a seizure?

There are many potential causes for seizures.

Primary: no underlying cause is identified. It may be a heredity condition or idiopathic (meaning there is no known cause).

Idiopathic epilepsy is usually seen in dogs aged 6 months to 6 years old and is a diagnosed after other diseases have been ruled out and all other tests and investigations are normal. It occurs much less commonly in cats compared to dogs and is usually seen in cats between 1-4 years of age.


  • Structural/intracranial (originating from within the brain). These can occur as a result of inflammation, infection, trauma, a blood clot or bleeding, developmental problems, brain tumours and degenerative brain diseases. These abnormalities can be confirmed by either MRI and/or cerebrospinal fluid analysis. These are more likely if your pet shows neurologic abnormalities between seizures.

  • Extracranial (originating from outside of the brain). This includes toxin exposure, metabolic disorders, liver disease or kidney disease. Blood tests are used to check for some of these causes.

Seizures in cats occur much less commonly than in dogs. Seizures are usually focal and may be characterised by abnormal behaviours or bursts of activity. They may occur as a result of trauma, infection, toxin exposure or a brain mass/lesion.

How is epilepsy treated?

Treatment is not instigated when only a single, isolated seizure has occurred. Indications for treatment include when cluster seizures or status epilepticus have occurred or when two or more seizures have occurred within a month.

Anti-epileptic drugs are not aimed at curing or completely eradicating seizures. Their purpose is to achieve better control of seizures, with an aim to reduce frequency to less than one every 6-8 weeks.

Monitoring concentrations of drugs by blood tests is important to ensure concentrations in the blood are at an effective level whilst avoiding any side effects. Tolerance to some drugs can occur over time and dosages and drugs may need to be adjusted according to your pet’s response and side effects. Not all drugs work equally well in all animals. If the desired reduction in seizures is not seen with ‘first line’ medications, additional or alternative medications may need to be used.

Ensure your pet remains on a consistent diet as changes to what they eat can affect absorption and blood concentrations of certain drugs. New diets are also currently being developed, which might help to further improve seizure control.

It is very important that you:

  • Give your pet their medication at the same time every day
  • Give the correct dosage of medication
  • Continue treatment and do not stop without first discussing with your vet

It is useful to keep a diary of when seizures occur in order to direct management of epilepsy and adjustment of medication. When observing seizures you should note:

  • Date and time it occurred
  • Which body parts were affected
  • How long each phase of the seizure lasted
  • Behaviour after the seizure

The Royal Veterinary College (RVC) have created an app (RVC Pet Epilepsy Tracker) which allows owners to electronically track seizures on their smart phone.

We hope you have found this article useful and interesting. If you are worried about your pet, give us a call on 01803 606059 (Torquay) or 843836 (Paignton).

Leave a Reply