Cat seizures: what to do during the fit, and what actually causes them

Quick answer

During a seizure there is almost nothing useful you can do to the cat, and several things that make it worse. What you can do is protect the cat from furniture, note the time, keep your hands away from its mouth, and film it.

Afterwards is where the value is. Most of what a vet needs to work out why a cat is fitting comes from your account of what happened before, during and after, and from what has been applied to any animal in the house in the last few days.

A calm look-over after the event tells you about vision, balance and awareness. During the seizure, watch and time it rather than handle the cat.

• Never put your hands or anything else near a seizing cat's mouth. Cats do not swallow their tongues, and the bite is severe.
• Time it. A seizure running past about five minutes, or a second one before the cat has fully recovered, is a life-threatening emergency.
• Cats seize differently from dogs. A great deal of feline seizure activity is focal: facial twitching, drooling, lip smacking, a fixed stare, or sudden running.
• A cat that has been in contact with a dog flea treatment containing permethrin is a poisoning emergency and needs a vet immediately.
• In cats, a seizure is more often a symptom of something else in the body than a primary epilepsy.

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Permethrin is the single most important thing to rule out.

Many spot-on flea products sold for dogs contain permethrin or a related synthetic pyrethroid. Cats cannot metabolise these compounds properly. A cat that has had a dog product applied to it, or that has groomed or slept against a recently treated dog, can develop muscle tremors, twitching and full seizures.

If this is possible, treat it as an emergency now. Telephone a veterinary practice before you set off, and say the word permethrin. While arranging transport, wash the cat with lukewarm water and a plain mild washing-up liquid to remove the product from the coat, keeping the cat warm afterwards, because a tremoring cat loses heat fast. Do not wait to see whether it settles.
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Decide in 60 seconds

What a seizure actually is, and what it looks like in a cat

A seizure is a burst of abnormal, synchronised electrical firing across a population of brain neurons. What you see depends entirely on which part of the brain is involved and how far the activity spreads.

Generalised seizure.

The classic form. The cat loses consciousness, falls on its side, becomes rigid and then paddles or jerks rhythmically. Salivation, urination and defecation are common. The cat is not aware and is not experiencing this as pain, however distressing it looks.

Focal seizure.

Activity stays localised. In cats this is common and easily missed. It looks like twitching on one side of the face, repetitive blinking, one ear flicking, chewing or lip smacking motions, drooling from one side, pupils widely dilated, a fixed vacant stare, or sudden unexplained running. The cat may remain partly aware.

Focal seizures matter clinically because they often point toward a localised problem in the brain, and because owners frequently describe them as odd behaviour rather than as a medical event.

Progression.

Focal activity can spread and become generalised. A cat whose facial twitching episodes have started to end in collapse is deteriorating and needs review, not a longer wait.

Cluster seizures and status epilepticus.

Two or more seizures in a short period without full recovery in between is a cluster. A single seizure that does not stop is status epilepticus. Veterinary practice commonly treats anything beyond about five minutes as status. Both cause body temperature to climb dangerously and both damage the brain, so both are true emergencies.

The post-ictal phase.

After the seizure ends the brain does not return to normal immediately. The cat may be blind, deaf, disorientated, unsteady, pacing, ravenously hungry, or defensive and likely to bite. This can last minutes or, occasionally, into the next day. It is not a second seizure and it is not permanent, but a post-ictal cat should be left alone in a safe, dim, quiet space.

What to do while it is happening

Look at the clock or start a timer on your phone. Duration is the number that decides everything else.

Clear the space around the cat. Move a coffee table, block a staircase, put a cushion between the cat and a table leg. Do not lift or carry a seizing cat unless it is somewhere genuinely dangerous such as a stair edge or near water, and if you must move it, slide it on a blanket rather than picking it up.

Keep your hands away from the mouth and head. Cats cannot swallow their tongues. Anything you put near the mouth will be bitten hard, through the jaw muscle spasm, and cat bites to the hand are a serious human injury.

Do not restrain the limbs or hold the cat down. Restraint does nothing to the electrical activity and it risks injuring the cat and you.

Turn the lights down and the television off. Reducing sensory input is the one supportive thing that is genuinely worth doing.

Film it. A short video from a metre away, with the whole cat in frame, is worth more than any description. If your phone shows a timer on screen, better still.

Keep other pets out of the room. Another cat will often react badly to a seizing housemate, and a fight afterwards is a common complication.

When it stops, leave the cat where it is, keep the room dim and quiet, and do not offer food or water until it is fully alert and swallowing normally.

A seizure diary and a weight recorded on the same day turn scattered episodes into a pattern a vet can work with.

Why cats seize, and how the list changes with age

In dogs, most recurrent seizures turn out to be primary epilepsy. In cats the balance is different, and a specific cause is found more often. That is a reason for investigation rather than a reason for pessimism.

Toxins.

Permethrin and related pyrethroids from dog flea products are the standout. Others include ethylene glycol antifreeze, certain rodent baits, some essential oils and diffuser products, and lead from old paint or curtain weights.

Metabolic causes.

Low blood sugar, particularly in a diabetic cat on insulin or a very young kitten. Liver disease producing hepatic encephalopathy, including portosystemic shunts in young cats, which typically cause dullness and seizures after meals. Severe kidney disease. High blood pressure, which in cats travels with kidney disease and with hyperthyroidism and can cause both seizures and sudden blindness.

Nutritional.

Thiamine deficiency causes neurological signs including seizures, a characteristic ventroflexed neck posture and pupil changes. It is associated with diets heavy in raw fish containing thiaminase, with badly formulated home-prepared diets, and occasionally with prolonged inappetence.

Structural brain disease.

Meningioma is the most common brain tumour in cats and is usually a disease of older animals. It often causes gradually worsening behaviour changes, circling and seizures. Importantly, many are surgically removable with good outcomes, so it is worth diagnosing.

Infectious and inflammatory disease.

Feline infectious peritonitis in its neurological form, toxoplasmosis, and disease associated with feline leukaemia virus or feline immunodeficiency virus.

Head trauma.

Seizures can appear immediately after an injury or weeks to months later.

Feline audiogenic reflex seizures.

A described syndrome in which specific high-frequency sounds trigger seizures: crumpling tin foil, a metal spoon on a ceramic bowl, tapping on a keyboard, jingling keys, a plastic bag. It affects older cats particularly and is over-represented in some breeds including Birmans. If your cat's episodes always follow a particular sound, say so, because it changes the diagnosis.

Primary epilepsy.

Diagnosed by exclusion, usually in younger adult cats, once imaging and blood work are clear.

Age shifts the odds. A first seizure in a cat under a year old raises questions of a shunt, an infection, a birth defect or a toxin. A first seizure in a cat over about seven raises the priority of a brain tumour, high blood pressure, kidney disease and hyperthyroidism, and makes blood pressure measurement and imaging more important.

What looks like a seizure but is not

Fainting from a heart problem.

Cats with underlying heart disease can collapse suddenly. The distinguishing features are that the cat goes limp rather than rigid, there is usually no paddling, recovery is quick and complete with no post-ictal confusion, and it often follows exertion or excitement. It is not less serious than a seizure, it is a different problem.

Aortic thromboembolism.

Sudden screaming, collapse, and one or both hind legs paralysed and cold. This is a clot event in a cat with heart disease. It is an extreme emergency and it is not a seizure.

Vestibular disease.

Head tilt, falling to one side, flicking eye movements, rolling. The cat stays conscious throughout.

Feline hyperaesthesia syndrome.

Skin rippling along the back, sudden frantic grooming of the flank or tail, dilated pupils, running and vocalising. Its relationship to seizure activity, skin disease and pain is not fully settled, which is exactly why it needs investigating rather than dismissing.

Sleep twitching.

Normal cats twitch, paddle and vocalise in sleep. A cat that wakes normally when you speak to it was dreaming.

Severe pain.

An acute painful event can produce vocalising, rigidity and collapse that owners reasonably describe as a fit.

Pupil size and whether the cat can track a slowly moving hand are two things worth checking once it is fully awake. Sudden blindness alongside seizures points strongly at blood pressure.

What never to do

Do not put your fingers, a spoon, a stick or a cloth in the cat's mouth. This is the most common and most damaging piece of folk first aid.

Do not restrain, hold down, or try to bring the cat round by shaking or shouting.

Do not give any human medicine. Paracetamol is lethal to cats in very small amounts, and human sedatives and anti-seizure drugs are not safe to improvise with.

Do not give leftover medication prescribed for another animal, and do not give a dose of an anti-seizure drug your cat had months ago without speaking to the vet first.

Do not offer food or water while the cat is still disorientated. A post-ictal cat can inhale it.

Do not put a post-ictal cat straight into a carrier with another animal or let a housemate cat approach it.

Do not apply any flea product to a cat that is not licensed for cats, and never split a dog product.

Do not decide a single seizure that stopped on its own can wait a fortnight. The first episode is the one where investigation is most likely to find something treatable.

Getting to the vet safely

Telephone first, always. It changes what happens on arrival and it lets staff prepare drugs for a cat that is still fitting.

Transport in a hard carrier lined with a towel, top-opening if you have one, so the cat can be lifted out rather than dragged. Cover the carrier with a towel to cut light and noise.

Do not drive with a seizing or post-ictal cat loose in the car or on someone's lap. A disorientated cat under a driver's pedals is how this becomes two emergencies.

Keep the cat warm on the journey if it has been tremoring or wet from a permethrin wash, but do not overheat a cat that has just had a prolonged seizure, because body temperature rises during seizure activity.

Take the product packaging with you if a toxin is possible.

When to get help

Go immediately, out of hours if necessary, for a seizure lasting more than about five minutes, a second seizure before full recovery, any suspicion of permethrin or another toxin, a cat that is unconscious or not breathing normally between episodes, head pressing, circling, or sudden blindness.

Be seen the same day for a first focal seizure, for facial twitching episodes, for any collapse in a cat with known heart disease, and for a cat that is still disorientated hours later.

Book within a day or two for a single generalised seizure that stopped on its own and was followed by full recovery.

Many causes of feline seizures are treatable, and several are curable. Investigation is what separates them.

Bring the video, the diary, the cat's current weight, a full list of every medication and parasite product used on every animal in the house, the diet including any raw fish, the cat's age and vaccination and virus test status, and a note of anything new in the environment. Expect the vet to want a full physical and neurological examination, blood and urine tests, blood pressure measurement, and in many cats imaging of the brain. That sequence is how a treatable cause gets found.