What does an epileptic seizure look like in a cat?
In cats, many seizures start as focal seizures, meaning they begin in one area of the brain, and they show mainly in the face. The cat may twitch its lips, whiskers or ears, chew at nothing, lick or swallow repeatedly and drool heavily. Some cats suddenly race around the house, have very dilated pupils, pass urine or faeces, or seem frightened for no reason.
A focal seizure can stay localised or spread to the whole brain. The cat then falls over, loses consciousness, goes stiff and makes paddling movements: this is a generalised seizure. In studies of cats with idiopathic epilepsy, about half had both focal and generalised seizures. Seizures usually last 1-3 minutes.
What happens after the seizure
In the post-ictal phase, the recovery period, a cat may be aggressive or disorientated, may seem unable to see or hear, may walk unsteadily, or may eat or drink a lot. Be careful when you touch your cat straight after a seizure, because it may scratch or bite without recognising you.
The different forms of seizure are explained in detail in the article on types of epileptic seizure.
What can be mistaken for a seizure in a cat?
Not every strange episode is a seizure. In cats, the vet has to tell seizures apart from fainting caused by heart disease, balance problems (vestibular syndrome), neck pain, compulsive behaviour, behaviour during a heat, feline hyperaesthesia syndrome (the skin along the back “ripples”, and the cat whips round and attacks its tail) and feline orofacial pain syndrome. That is why a video of the episode is so useful.
What causes epilepsy in cats?
In cats, a specific cause in the brain is found more often than in dogs. In a review of published studies, structural epilepsy (caused by a lesion in the brain) accounted for 40-70% of recurrent seizure disorders in cats, idiopathic epilepsy (no cause identified) for 22-57%, and reactive seizures (caused by a problem outside the brain) for roughly 15-25%. The figures vary widely between studies.
Causes in the brain (structural)
- tumours, especially meningioma (a tumour of the membranes covering the brain), lymphoma and glioma;
- inflammation and infection of the brain, for example feline infectious peritonitis (FIP), toxoplasmosis or cryptococcosis;
- head injuries and problems with the blood vessels;
- hippocampal necrosis, a lesion described in cats in recent years, associated with cluster seizures, drooling and aggression.
Causes outside the brain (reactive seizures)
- low blood sugar, low calcium;
- liver disease, including a portosystemic shunt (an abnormality of the blood vessels of the liver). In cats, routine blood tests can come back normal even when a shunt is present;
- poisoning, for example with insecticides. A common scenario: a permethrin spot-on flea treatment meant for dogs, put on a cat. In a study of 286 exposed cats, 87.8% had tremors, muscle twitching or convulsions.
At what age does it start?
Cats with idiopathic epilepsy were on average younger when the seizures started, around 3.5-4.6 years, compared with about 8 years in cats with a structural cause. The age ranges overlap, so age alone does not tell you the cause.
How is epilepsy diagnosed in cats?
The diagnosis follows the same steps as in dogs, with a few particular points. It starts with the history, a video and the clinical and neurological examination. Next come blood and urine tests, bile acids to check the liver, a blood pressure measurement and, in older cats, thyroid tests. If the results do not explain the seizures, the next step is an MRI scan of the brain and analysis of the cerebrospinal fluid (CSF, the fluid around the brain), which can reveal tumours, inflammation or infection.
Electroencephalography (EEG) is used less often in cats than in dogs, and its value for routine diagnosis in this species is not yet well established. The diagnostic steps are covered in detail in the article on causes of seizures and diagnosis.
A neurological consultation tells you where the problem comes from and what to do next.
How is epilepsy treated in cats?
If a cause is found, the cause is treated first: the infection, the inflammation, the liver problem or the poisoning. Anti-epileptic treatment is considered mainly when seizures are frequent, come in clusters or there is a known lesion in the brain. The vet decides on the medicine, the dose and how long treatment lasts, and some medicines need regular blood tests.
Results in cats are generally encouraging. In one study of cats with suspected idiopathic epilepsy, about 40% became seizure-free, another 40% had their seizure count at least halved, and about 20% did not respond to treatment. In another study, of 76 cats with epilepsy of unknown cause, 42% went into complete remission. Even so, treatment must never be stopped on your own: it is reduced only after a long seizure-free period, gradually and on your vet's advice.
How long does a cat with epilepsy live?
Many cats with epilepsy live for years with a normal life. Cats that have seizures but no other neurological signs in between generally have a good prognosis. In the Swiss study of 76 cats with epilepsy of unknown cause, 91% were still alive at the time of follow-up, at least a year after discharge. With structural epilepsy, life expectancy and quality of life depend on the cause found: a treatable infection or inflammation follows a different course from a tumour. Your vet can only give you a realistic prognosis after investigations.
How does epilepsy in cats differ from epilepsy in dogs?
| Cats | Dogs | |
|---|---|---|
| Typical appearance of seizures | Often focal, with signs in the face (drooling, twitching, chewing), sometimes becoming generalised | Most often focal, spreading to the whole body (generalisation) |
| Most common cause | Structural causes are found often, in many studies in close to half of cats or more | Idiopathic epilepsy |
| Role of genetics | Little evidence | Likely inherited predisposition in many breeds |
| Remission on treatment | Reported relatively often (around 40% in some studies) | Rarer, roughly 15-30% in hospital-based studies |
For comparison, you will find the information on dogs in the article on epilepsy in dogs.
When is it an emergency?
If a seizure lasts longer than 5 minutes, if your cat has one seizure after another without recovering in between, or if you suspect poisoning, go straight to the nearest emergency vet clinic that is open now. The practical steps are set out in the article what to do during a seizure. To investigate repeated seizures once your cat is stable, you can book an epilepsy consultation.
Frequently asked questions
My cat is foaming at the mouth and trembling. Is it a seizure?
It may be, but not necessarily. Drooling and tremors also occur with poisoning, particularly when a flea or tick product meant for dogs has been put on a cat, or with severe stress. If the episode does not stop within a few minutes or your cat does not come round, go straight to the nearest emergency vet clinic that is open now.
Can indoor cats have epilepsy?
Yes. Epilepsy has nothing to do with lifestyle. Some causes, such as head injuries or certain infections, are more likely in cats that go outdoors, but seizures can happen in any cat.
Can my cat's seizures be triggered at certain times of day?
In cats with idiopathic epilepsy, seizures have most often been seen at rest rather than during activity. Write down in your seizure diary the time and what your cat was doing beforehand, because these details help with the diagnosis.
Can a cat pass epilepsy on to her kittens?
Unlike in dogs, there is very little evidence in cats for a genetic cause of idiopathic epilepsy. It is not a contagious disease.
Sources
- Pakozdy A., Halasz P., Klang A. 2014, Epilepsy in cats: theory and practice, Journal of Veterinary Internal Medicine 28(2):255-263
- Hazenfratz M., Taylor S.M. 2018, Recurrent seizures in cats: diagnostic approach, when is it idiopathic epilepsy?, Journal of Feline Medicine and Surgery
- Szelecsenyi A.C. et al. 2017, Survival in 76 cats with epilepsy of unknown cause, Veterinary Record 181(18):479
- Sutton N.M. et al. 2007, Feline permethrin spot-on poisonings reported to the VPIS London, Journal of Feline Medicine and Surgery 9(4):335-339
- Berendt M. et al. 2015, International veterinary epilepsy task force consensus report on epilepsy definition, classification and terminology in companion animals, BMC Veterinary Research 11:182
- Potschka H. et al. 2015, International veterinary epilepsy task force: consensus proposal: outcome of therapeutic interventions in canine and feline epilepsy, BMC Veterinary Research 11:177
This article is for information only and does not replace a veterinary consultation.