“Cats are not small dogs”
When I trained as a vet in the 1980s, cats had only been treated in their own right for about a decade. (Astonishing I know!) To prove how far things had come in the last ten years, the lecturers often said, “Cats are not small dogs”….and then illustrated the point with a piece of new research that highlighted how ridiculous it was that veterinary medicine ever put cats in the same category as dogs.
The reason for this anecdote is that epilepsy and seizures in cats are a perfect illustration of the uniqueness of our feline friends. For example, epilepsy is relatively common in dogs, but exceedingly rare in cats. Seizures also.
At this point I’m duty bound to digress and point out the difference between seizures and epilepsy.
- Seizures: Fits that happen as a result of underlying health problems such as high blood pressure.
- Epilepsy: Fits for which no underlying cause is found (and are the result of unexplained abnormal electrical discharges in the brain).
Again, seizures are unusual in cats (in contrast to our canine companions) and when they do occur it’s usually as a complication of another problem.
What do I mean by this?
Older cats are most at risk of seizures. But this is no coincidence. Older cats are more likely to have high blood pressure, or kidney disease, or an overactive thyroid gland: All of these conditions have the potential to cause seizures.
This is an important point to grasp because the treatment for these fits is not anticonvulsants, but to correct the underlying problem. For example, treat the cat’s high blood pressure with a medication called amlodipine and the seizures should stop. See the difference?
What are the Common Causes of Seizures in Cats?
In Young Cats
Fits are rare and usually the result of hydrocephalus (water on the brain) or a porto-systemic shunt (PSS). The latter is a congenital problem where a blood vessel that bypasses the liver in the womb, fails to shut down after birth. The upshot is ammonia builds up to toxic levels in the blood stream, affects the brain (a condition known as hepatic encephalopathy), and causes seizures. Another cause is feline infectious peritonitis (FIP) which can infect the central nervous system.
In Older Cats
Seizures most commonly arise because of other health problems, such as:
- Hypertension: high blood pressure predisposes cats to blindness, seizures, and strokes
- Liver Disease: toxins build up in the bloodstream that are poisonous to the brain
- Kidney Disease: urea and ammonia in the bloodstream have a harmful effect
- Hyperthyroidism: high levels of thyroid hormone cause excessive stimulation of the central nervous system
- Low Blood Sugar Levels: this happens in diabetic cats when an owner gives too much insulin, or because of a form of pancreatic cancer (insulinoma).
- FARS: feline audiogenic reflex seizures or a condition in older cats where an over sensitivity to sound triggers seizures.
In Curious Cats
Unfortunately curiosity is also a risk factor for seizures. There are many household chemicals which cats are exposed to which are potentially harmful, and seizures are just one of the complications. These include substances such as insecticides and herbicides (carbamate), bird and mole killers (alphachloralose), rodenticides (bromethalin and strychnine), and other chemicals such as metaldehyde and organophosphates.
Whilst most cats are pretty good at not eating things they shouldn’t, what may happen is their fur becomes contaminated with chemicals, which are then swallowed when the cat grooms.
If Your Cat has a Seizure…
Whilst seizures are alarming to witness, the cat won’t know what’s happening and fits usually last no more than two to three minutes.
Noises and bright light stimulate the brain, and can worsen or prolong a seizure. Help the cat by staying calm. Look around you and turn off anything that might stimulate the cat. This includes turning of lights and the TV, and getting everyone (quietly!) out of the room.
Don’t move or touch the cat whilst they’re having a seizure. Instead, ensure they are safe by putting cushions between them and any sharp objects such as table legs. Turn off any electrical appliances (especially heaters) so these don’t pose a hazard.
If you can, video the episode on your phone as this can give the vet valuable information at a later date. Also, time the seizure. If it lasts more than five minutes then your vet needs to know right away.
Once the seizure is over, the cat may be hungry and thirsty, so let them eat and drink. Phone your vet for advice and follow their instructions. The vet may well want to see the cat and check them over, including measuring blood pressure and screening blood tests to trouble shoot for those underlying problems. Sadly, a small percentage of older cats do have seizures as a result of a brain tumour, in which case this won’t be detectable on tests unless the cat has an MRI scan.
What about Epilepsy in Cats?
You’ve probably guessed by now that this is exceedingly rare in cats (unlike in dogs). When it does happen it is a “diagnosis of exclusion” which means that all other tests (including an MRI scan) turned up normal or negative – Only then can epilepsy be truly diagnosed, and the rare cases where this happens are usually young cats under the age of five.
For cases of true epilepsy anticonvulsants are prescribed, but the effects are less predictable than in dogs, which brings us neatly back to the beginning and: “Cats are not small dogs.”
Dr Pippa Elliott BVMS MRCVS is a veterinarian with 27-years’ experience in practice and a special interest in feline medicine and behaviour. Pippa is housekeeping staff to four highly individual cats that conspire to keep her busy opening doors on demand.