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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 characterised by a
variety of signs including sleepiness, pacing, depression, excitement, excessive
eating and drinking. Generalised
seizures
(= a grand mal seizure) - jerking movements, rigid limbs,
paddling/running movements, loss of faecal 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
characterised by behavioural changes (e.g. tail chasing, biting at
imaginary objects, aggression). (Absence
seizures (=
petit mal seizure) - very rarely recognised 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 centre. 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 anaesthetic 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 centres. 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 vet 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 the 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 the veterinary practice
should be informed. DO
NOT BE TEMPTED TO CHANGE THE DOSE OR TIMING OF MEDICATION WITHOUT CONSULTING
YOUR VETERINARY SURGEON FIRST 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 required
during 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. |