Seizures in Dogs and Cats

What is a seizure?

A seizure is a temporary episode of abnormal electrical activity in the brain. It may cause involuntary movement, altered awareness, unusual behaviour or loss of consciousness. Epilepsy means a tendency to have recurrent unprovoked seizures; it is not the name of every single seizure event.

What might a seizure look like?

Seizures may be generalised or focal:

Generalised seizures often cause collapse, loss of consciousness, body stiffening, paddling or jerking movements, drooling, jaw movements, and sometimes urination or defecation.
Focal seizures affect one area of the brain and may cause facial twitching, repeated chewing or lip-smacking, jerking of one
limb, staring, sudden abnormal behaviour or brief periods of reduced awareness.

Cats are relatively more likely than dogs to show focal signs, although focal seizures can progress to a generalised seizure.

What happens before and after a seizure?

Before the seizure, some pets become restless, clingy, anxious, hide or behave unusually.
During the seizure, awareness may be reduced or absent and movements are involuntary.
Afterwards, the post-ictal period may include confusion, pacing, temporary blindness, hunger, thirst, restlessness, sleepiness or unusual behaviour. Recovery may take minutes to several hours.

A prolonged period of disorientation after an episode supports a seizure rather than a simple faint, although video and veterinary assessment are often needed to distinguish them.

What should I do during a seizure?

Start a timer and, if safe, record a video.
Move furniture or objects away and block access to stairs, pools and sharp edges.
Dim lights, reduce noise and keep other pets and children away.
Do not restrain your pet unless needed to prevent an immediate fall or injury.
Do not put your hands, food, water or any object in your pet’s mouth. Pets do not swallow their tongue, and involuntary jaw movements can cause serious bites.
After the seizure, allow quiet recovery in a safe area and approach cautiously because your pet may be confused and may not recognise you.

Only give emergency seizure medication if it has been prescribed for your pet and you have been shown exactly how and when to use it.

When is it an emergency?

A seizure lasts five minutes or longer.
A second seizure begins before your pet has fully recovered from the first.
More than two self-limiting seizures occur within 24 hours (cluster seizures).
Your pet has difficulty breathing, severe overheating, collapse or injury.
A toxin exposure, head trauma, pregnancy-related problem or low blood sugar is possible.
This is your pet’s first seizure.
Status epilepticus and cluster seizures can cause overheating, low oxygen, metabolic complications and brain injury. Early treatment improves the chance of seizure control.

What causes seizures?

Causes are commonly grouped into three categories:

Reactive seizures: the brain reacts to a problem elsewhere in the body, such as low blood sugar, liver or kidney disease, electrolyte abnormalities, toxins or certain medications.
Structural seizures: disease within the brain, such as inflammation, infection, trauma, stroke, a congenital abnormality or tumour.
Idiopathic epilepsy: recurrent seizures without an identified metabolic or structural cause, often with a presumed genetic basis. This is common in dogs but less commonly diagnosed in cats.

Age, species, breed, examination findings and behaviour between seizures help determine which causes are most likely.

How are seizures investigated?

Your veterinarian will ask about the event, possible toxin exposure, medications and previous illness, then perform a physical and neurological examination.

Blood tests to assess glucose, electrolytes, liver and kidney function and other metabolic causes
Urine testing and blood pressure measurement when indicated
Additional infectious-disease or toxin testing based on the history
MRI or CT of the brain and cerebrospinal fluid testing when structural or inflammatory brain disease is suspected

A clear video and a written seizure diary recording date, duration, signs and recovery are extremely useful.

How are emergency seizures treated?

Emergency treatment aims to stop seizure activity quickly, protect breathing and circulation, control body temperature and identify reversible causes.

Fast-acting anti-seizure medication, commonly a benzodiazepine such as midazolam or diazepam
Longer-acting anti-seizure medication if seizures recur or continue
Oxygen, intravenous access, glucose and electrolyte correction, temperature control and supportive care
Anaesthesia and intensive care for seizures that do not respond to initial treatment

For pets known to develop cluster seizures, a veterinarian may prescribe a home rescue plan. Intranasal midazolam is commonly preferred where appropriate because it can act rapidly and avoids placing hands near the mouth.

Will my pet need long-term medication?

Not every pet requires daily medication after one short seizure. Long-term treatment is more likely to be recommended when seizures are frequent, occur in clusters, last five minutes or longer, cause severe recovery periods, or when brain disease is identified.

Common medications include phenobarbital, levetiracetam, potassium bromide in dogs, and zonisamide. The best choice depends on the species, underlying disease, seizure pattern and other medications.

The aim is usually to reduce seizure frequency and severity while maintaining a good quality of life; complete elimination of every seizure is not always possible.

Care after a seizure

Keep your pet in a quiet, cool and secure area until fully coordinated and aware.
Offer small amounts of water only once swallowing and awareness are normal.
Avoid stairs, swimming, heights and unsupervised outdoor access during recovery.
Contact your veterinarian after a first seizure or any meaningful change in an established seizure pattern.

Seek immediate veterinary care if:

The seizure reaches five minutes
Another seizure starts before full recovery
More than two seizures occur within 24 hours
Your pet remains severely disoriented, blind, weak or unable to stand
Breathing difficulty, overheating, trauma or possible poisoning is present

Clinically reviewed and approved by Dr Giulia Agostini, Pet Emergency Senior Veterinarian and Clinical Manager, DVM MANZCVS (ECC) August 2026