SEIZURES IN CATS

Seizures and epilepsy are less commonly encountered in cats than dogs. They are, however, the most common sign of disease affecting the front part of the brain in the cat.

Some important terms:-

Seizure (convulsion, ictus, fit) - an involuntary disturbance of normal brain control which is usually seen as uncontrollable muscle activity. Seizures can be single and very occasional or may occur in clusters followed by long periods (weeks to months) without fitting.

Epilepsy - recurrent seizures.

Preictal (aura) - the change in character that occurs prior to a fit e.g. nervousness, attention seeking, head turning.

Postictal - following a seizures it can take 24-48 hours for a cat to return to normal. This period is called the postictal phase and is characterized by a variety of signs including sleepiness, pacing, depression, excitement, excessive eating and drinking.

Generalized seizures (= a grand mal seizure) - jerking movements, rigid limbs, paddling/running movements, loss of fecal and urinary control. The head is often bent backwards along the spine.

Status epilepticus - continuous fitting for more than 5-10 minutes. Cats in status require urgent treatment.

Partial seizures - very rare in cats may involve only certain muscle groups or be characterized by behavioral changes (e.g. tail chasing, biting at imaginary objects, aggression).

(Absence seizures (= petit mal seizure) - very rarely recognized in cats.)

Seizures often occur at times of changing brain activity e.g. during phases of sleep, excitement or feeding. Affected cats can appear completely normal in between fits. Many different diseases can lead to seizures so it may be important that diagnostic tests are performed to try to discover the cause of the fitting as treatment of the underlying disease is most likely to lead to successful control of the seizures. In cats, idiopathic epilepsy, which occurs commonly in some breeds of dog e.g. German Shepherds, is rare.

How can I help my veterinary surgeon to make a diagnosis ?

Carefully observing your cat particularly at the beginning of a fit can provided very valuable information to your veterinary surgeon about the types of disease that may be causing the problem.

1. Age at which fits began, are they getting worse?

2. Chronicity - i.e. are the seizures intermittent or did they develop suddenly ?

3. Frequency, multiplicity of seizures

4. Association of seizures i.e. asleep, excitement, feeding

5. Other signs of ill health e.g. poor appetite, excessive drinking, reduced exercise

Information about your cat's lifestyle may also be important

6. Medication use - especially recent worming or use of flea control products.

7. Diet

8. Access to poisons

Both diseases which involve the brain directly (intracranial) and conditions which affect other body systems (extracranial) e.g. the liver or kidney disease can cause fitting. With recent developments in treatment many diseases which have previously been untreatable may now be treated though this can require referral to a specialist center.

How can a diagnosis of the cause of the seizures made ?

A range of tests are often needed before a final diagnosis can be made, initially this is likely to involve blood samples to look for extracranial causes of the fitting. Following this a general anesthetic may be required to allow x-rays of the skull to be taken and the fluid that surrounds the brain (cerebrospinal fluid) sampled. In order to actually look at the brain, powerful imaging techniques are required e.g. magnetic resonance imaging (MRI) and computer assisted tomography (CT), these tests are only available at a limited number of specialist centers.

What treatments are available ?

It is important that a cat which is having regular seizures (more than one every 6-8 weeks) receives treatment even if the cause is not as yet clear as each fit can lead to further brain damage increasing the likelihood of more fits in the future. Treatment of the underlying causes of fits is without the scope of this leaflet. In some cases where the cause of the fitting is not known or is untreatable then the seizures need to be treated directly. A variety of treatments are available, the treatment chosen will depend on a each individual cases. Several changes of dose rate, timing and drug may be required before the regime that suits your cat best is found. This can be a frustrating time but the benefits of finding the right treatment become self evident. Even with treatment it may not be possible to completely prevent fitting, in many cases the aim is to reduce the seizures so your cat can lead a more or less normal life.

Golden rules of treatment

ALWAYS follow the instructions on the label both the dose rate and timing of the medication is important to maintain adequate drug levels in the bloodstream.

NEVER run out of the medication as sudden withdrawal of treatment can lead to serious fitting.

LET your veterinarian know when your supply is running low so a repeat prescription can be arranged. This is particularly important if the treatment needs to be ordered specially for your cat.

KEEP these drugs safe as they can be powerful sedatives.

BE CAREFUL about other drugs including herbal remedies that you also give your cat. If in doubt check with your veterinary practice.

What are the side effects of treatment ?

Mild side effects are common particularly at the beginning of treatment or following changes in the regime. The most common side effect is sedation but other signs can also occur, most disappear quite rapidly as the cat becomes used to the medication. If side effects persist or seem severe then your veterinary practice should be informed.

Why has treatment failed?

Sometimes treatment will appear to have failed, in many cases this is because the dosage and timing of the medication is not yet right. Please check that you are following the instructions on the medication label correctly. In some cases your veterinary surgeon may want to take a blood sample to ensure that your cat has adequate circulating blood levels of the medication.

Other causes of treatment failure include:-

1. Specific circumstances e.g. stress - increased medication may be requiredduring such periods.

2. Progression of disease.

3. Some cases are uncontrollable even with medication.

Seizures are generally a sign of fairly severe disease, this does not necessarily mean that nothing can be done for your cat, with the correct treatment, the quality of your cat's life can be dramatically improved.

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