EPILEPSY IN THE DOG
 
 

Epilepsy occurs in most of the species treated by your vet but is most common in the dog.  An epileptic fit often appears suddenly, causing a dramatic change in attitude and a distorted posture, leaving the owner to feel first panic and then severe shock.  Often it is not easy for the concerned owner to accept that the dog is neither in pain nor likely to suffer serious injury from an attack.  The alarm experienced by onlookers makes the vet's work particularly difficult because epileptic fits are usually quite short and the patient appears normal by the time he sees it.  This means he has to rely on others for a description of the attack, and panic and shock are not conducive to accurate observation.
 
 

The successful treatment and management of animals with fits depends essentially on teamwork; on the specialised knowledge of the vet, on the common sense and powers of observation of the owner, and above
 
 

It is hoped that this leaflet will promote this teamwork and at the same time help to allay some of the fears and misunderstandings the owner of an epileptic dog may feel.
 
 

WHAT IS EPILEPSY AND WHAT CAUSES IT?

The brain is an extremely complex organ consisting of many millions of nerve cells or neurones .  When stimulated these neurones pass messages by means of depolarisation - small fluctuations in electrical charge.  All neurones are well insulated and are only normally depolarised when a large enough stimulus affects them.  The stimulus is then said to be greater than the threshold of the neurone.

        Under normal conditions the amount of activity in the brain is relatively small and under strict control, only a percentage of neurones are working at any one time.  During a fit (seizure, convulsion or ictus) this control breaks down and large parts of the brain discharge at the same time giving rise to the typical signs which are covered later.

        The massive discharge which causes a fit can arise for a number of reasons :-
 
 

•       In some individuals the threshold of the neurones or the amount of insulation between them is abnormally low.

For example in Primary Epilepsy - a hereditary condition which is more common in certain breeds (G.S.D., St. Bernard, Irish Setter, Poodle and Beagle).
 
 

•       Drugs, toxins, poisons or infections may decrease the threshold to fits in an otherwise normal dog.

For example :-  in Canine Distemper

                Encephalitis and Meningitis - infections of the brain

                        Poisonings - such as metaldehyde (slug bait) and warfarin

                        Liver and kidney disease
 
 

•       Damage or pressure on the brain may act as a focus of hyperexcitability.

For example :- Head injuries

                        Brain Tumours

                        Strokes and Cerebro-vascular disease - damage to blood vessels in the brain.

                        Hydrocephalus - fluid on the brain
 
 

•       Excessive stimulation of the peripheral nervous system.

For example :- in Puppies which are teething or have a parasitic worm infection
 
 

There are several important points to remember:
 
 

? Any animal is capable of having a fit given a large enough stimulus, but the epileptic animal convulses much more readily than the majority of its species - its fit threshold is lower.

?  A fit is a sign of an underlying disease not a diagnosis in itself. Just as for example lameness is a sign which may be caused by many conditions such as a broken bone, a muscle strain, a cut pad or arthritis.

?  An animal is an epileptic only if it suffers from recurrent fits.  It is possible for a dog to have only one or a few fits due for example to a transient infection or poisoning from which it subsequently recovers.  It would be unwise to label such an animal as an epileptic and treat it as one for the rest of its life.
 
 

RECOGNISING A SEIZURE
 
 

The signs which a dog may display during a fit are variable and depend upon the areas of the brain involved and the size of the discharge.  A typical seizure consists of the following;-
 
 

Aura    the first phase that precedes the actual fit and lasts for as little as a few minutes or as long as several days.  In certain types of epilepsy there may be no aura.

Signs to look for;      -  Restlessness, whining, shaking

        -  Dazed appearance

                                -  Change in temperament

                                - Twitching of muscles
 
 

Seizure/Fit/Convulsion or Ictus

The attack is usually short in duration - between 1 and 15 minutes (most commonly between 1 and 3 minutes).

Signs to look for;      -  Collapse, unconsciousness

                                -  Tonic spasm (legs held rigid)

                                -  Clonic spasm (jerky leg movements, running movements,                                                        paddling, eye movements, rapid respiration.)

                        &/or    -  Salivation, urination, defecation

                        or      -  Flaccid paralysis, unresponsive dilated pupils
 
 

Post-ictal Phase

Immediately follows the seizure.  It can last from just a few minutes to several hours. The severity of signs vary a great deal from dog to dog.

Signs to look for;      -  Transient blindness

                        -  Restlessness, poor co-ordination, confusion

                        -  Apprehension, barking, aggression

                        -  Ravenous appetite and thirst, chewing, salivation
 
 

These three phases are seen in typical epileptic fits with various combinations of the signs listed.  However not all attacks follow this pattern; some dogs may have atypical fits in which they exhibit other signs such as bizarre behavioural abnormalities, brief periods of rigidity, or even running attacks.  A complete description of the animal before, during and after any seizure will greatly aid your vet in diagnosis, especially in atypical cases.  For this reason you should fill in the record sheet attached to the back of this leaflet as soon as possible after each seizure.
 
 

The essential features of an epileptic fit which distinguish it from most other attacks with which it could be confused (e.g. heart attacks, fainting, metabolic and spinal disorders), are that -

a)  It occurs when the animal is relaxed in its own home surroundings, and frequently when the animal is asleep.  This is because the threshold for fits is lower in a relaxed animal and therefore a smaller stimulus will cause one.  Heart attacks often occur when the animal is excited or frightened, or has suddenly  exerted itself.
 
 

b)   The animal is completely disconnected from its surroundings for at least part of the fit.  Almost all owners make some attempt to control or comfort their dog, and can say whether or not the animal made any effort to respond.  This is probably the most useful single criterion for differentiating between heart attacks and fits.  During a fit no response is shown, but during a heart attack the dog will show its response to its owner by eye movements, or by struggling to rise.
 
 

Other useful points to remember:-

        This onset of a fit is usually sudden and without vocalisation.

        The animal may have difficulty regaining use of its hind legs after a fit.

        The colour of the tongue and mucous membranes remains pink in a fit.

Because of the muscular exertion of a fit the dog will often have a pounding heart and fast breathing afterwards. This does not indicate that it has had a heart attack.  The abnormal pulse and respiration are a consequence of the attack not a cause of it.
 
 

There is no correlation between the severity of the signs shown in a fit and the underlying disease causing it - severe fits do not necessarily originate from severe brain conditions such as tumours.
 
 

Animals are UNCONSCIOUS during a fit.  The grotesque appearance of a convulsing animal is not an expression of pain (our evidence for this comes from human epileptics).  Dogs have no untoward memory of the fit afterwards.  It is no exaggeration to say that often the owners are more distressed by the fit than the dog.
 
 
 
 

DIAGNOSING THE CAUSE OF EPILEPSY

A fit is a sign of an underlying disease not a diagnosis in itself.  Thus once a dog has been shown to have suffered from a fit and other attacks have been eliminated, your vet will try to find the cause of the seizure.

        As we have seen there are many causes of epilepsy and so diagnosis is not always easy.  Your vet will give your dog a complete physical examination, however the most important points are often from an owner's own observations.  Do not be surprised if you are asked many varied questions, some of which seem to have no bearing on the fits - many pieces of information are needed to build up a complete picture and narrow down the causes.

        In some cases one or more specialised investigations may be needed to help establish a diagnosis.  These may include taking blood, urine and faeces samples as well as ophthalmology or radiography.  Finally advise from a specialist, such as a consultant neurologist with access to EEG (Electro-encephalography) may be sought.

        In some dogs it may take months or even years to establish a cause for the fits.  Sometimes an absolute diagnosis is never reached.  Patience and trust is needed by all involved in such cases and it may be helpful to keep the following points in mine:-
 
 

Veterinary knowledge on epilepsy is not absolute - there are still many things we have yet to discover.  Many of the causes of epilepsy still remain obscure.
 
 

Most veterinary surgeons do not have access to the sophisticated equipment that hospitals have for the diagnosis of human epilepsy.  Many of the more complicated tests are expensive to perform, so your vet will not advise their use unless absolutely necessary.
 
 

In many cases an absolute diagnosis is not necessary for the successful treatment of the dog.  Often is more important for certain causes to be eliminated - such as those which have a poor outlook or need special treatment.
 
 

Forming a Treatment Plan

After their dog has experienced its first fit many owners confront their vet while still feeling shocked and confused.  It is difficult for them to believe that their dog has not suffered severe pain and will not die in the near future, and so they expect treatment straight away.  This makes their vet's actions hard to understand - often if the first fit has not been severe no treatment is given.

        As has been stated, for an animal to be called an epileptic it has to have recurrent fits.  It would be unwise to put a dog straight onto anti-convulsant drugs when the fit may be an isolated incident.  If the fits do recur, but are mild and infrequent (many months apart), it may also be best not to put the dog onto anti-convulsants but to save them for future use.  Some dogs become gradually resistant to the effects of anti-convulsant drugs and increasing doses have to be used; so the longer their use can be delayed the better.

        The decision to instigate any treatment strategy with anti-convulsants depends upon many individual factors and should not be taken on the spur of the moment.  It is better to take time so that the owner can understand the problems more fully, the vet can investigate the causes, and some discussion can take place between them.  Therapy can then be initiated at the optimum time for the dog and not merely to alleviate the panic an owner may feel.
 
 

What treatment is available for epilepsy? Treatment can be divided into two types; firstly, if your vet has been able to diagnose the cause he may be able to treat it ; secondly symptomatic treatment of the fits by anti-convulsants can be instituted as and when necessary.
 
 

1)      Treatment of the underlying cause.

In certain cases where your vet has been able to diagnose the cause of the fits he may be able to act directly against it.  For example by the use of antibiotics against infections, diuretics against hydrocephalus, wormers against parasitic infestations or changing the diet in kidney disease.  Unfortunately the number of cases in which this can be done is limited and often the damage has already been done.
 
 

2)      Treatment of the fits with anti-convulsants.

For most dogs anti-convulsant drugs are the treatment of choice, but they are not given automatically - only when necessary.

        The most common drug in use is Phenobarbitone but other drugs or combinations of drugs may also be prescribed.  By various means all anitconvulsant drugs decrease the chance of a fit occurring by increasing the threshold to fits, or decrease the size of the fit by stopping the spread of the discharge.
 
 
 
 

There are four very important points to remember -
 
 

•       There is no fixed dose rate for any anti-convulsant.

Teamwork and co-operation are required to determine the correct dose rate of anti-convulsants.  When medication is given by mouth and the site of action is in the brain, many factors such as absorption and transport affect the result; hence a certain amount of trial and error is inevitable.  Even the selection of the ideal anti-convulsant cannot be forecast with certainty and every patient must be considered as an individual case.
 
 

•       An anti-convulsant must be given regularly, not just at the time of the fits.

Oral medication usually takes at least several days to reach therapeutic levels and so seizures may still take place shortly after medication is instituted.  Once on an anti-convulsant drug medication must then be continued on a regular basis.  Any change in medication must be made gradually on the advice of your vet.  The sudden discontinuation of anti-convulsants in epileptic dogs will often precipitate a series of seizures or even status epilepticus.
 
 

•       In almost every seizure disorder, even those well controlled, some relapses will occur.

An anti-convulsant will not necessarily control the fits completely because the high dose rate could produce severe side-effects.  But medication should reduce the frequency and/or severity of fits.
 
 

•       Anti-convulsant drugs may produce certain side-effects.

The most common of these is poor co-ordination, which usually wears off after a few days.  If it persists the dose may be too large and you should contact your vet.  other possible side-effects are increased thirst and sometimes increased hunger.  These effects usually decrease after a few weeks.  If you feel medication may be causing any ill effects to your dog other than these contact your vet for advice - do not just discontinue use of the drug.
 
 

It is not desirable to give continuous medication to a dog for a number of years because habituation occurs, and ever increasing doses are needed.  The ideal scheme is to find a drug and dose which control the fits to an acceptable frequency, and then gradually reduce the dose and, hopefully, eventually withdraw it altogether.  The dog can then be left without medication until the fits recur at sufficiently short intervals to warrant further therapy.  With this regime the dose can be kept low enough to avoid serious side-effects.  Many dogs suffering from epilepsy live a normal life-span if treated in this way and finally die from some other cause.

        Sometimes the results are less good and may provide either an acute emergency or a chronic problem -
 
 

a)      Acute Emergencies.

The acute emergency is STATUS EPILEPTICUS  ; when the dog has one fit after another for a period of hours.  This situation will end fatally if not treated correctly.  Your vet must be contacted immediately if your dog has more fits than normal, especially if they are more severe.  The most common cause of status epilepticus is the sudden cessation of medication, either due to an oversight or failure to appreciate the need for continuous medication.  Although status epilepticus is a very serious condition, many epileptics have just one incidence of it in their lives and live for many years after such an incident.
 
 

b)      Chronic Problems.

The Chronic problem is less well understood.  Some dogs whose fits have been reasonable controlled with anti-convulsants for years suddenly seem to be refractory to their effect, and even large doses no longer control the frequency of the fits to any appreciable extent.  The situation may be due to some change in the brain cells, or to a decrease in the animal's ability to absorb and transport the drug, or to some other factor having an adverse effect on cerebral function (such as cerebral tumour or a head injury).

           If the dog has a mild toxaemia from some illness unconnected with the central nervous system (e.g. kidney disease), the frequency of fits in an epileptic dog may increase.  This does not necessarily indicate any permanent deterioration in the brain, and if the illness is treated successfully, the fit frequency will in due course revert to its former level.

               In other dogs there is no obvious solution.  Because a change in the pattern of seizures may indicate that medication is no longer working, sometimes a change of anti-convulsant helps.  Otherwise the outlook may be grave.
 
 

The Future
 
 

Despite the problems which have just been mentioned, many dogs are treated successfully and live long and happy lives.

        The outlook for an epileptic dog does depend to some extent on the cause of the fits.  Some underlying causes are progressive and the epilepsy will be expected to get gradually worse : conversely, in some cases the causes can be eliminated and the size and frequency of the fits will be expected to reduce.  Your vet will be able to advise you of his opinion of the outlook based on the individual facts of your case.  However it must be stated that even in the most serious cases where there is a progressive structural disease such as a brain tumour, the epilepsy can usually be at least partly controlled, and the dog's happy life-span increased.
 
 

Some useful points to bear in mind are -

?       Animals seldom die from a fit, except in status epilepticus
 
 

?       In general the younger the animal and the longer it has had the fits already, the more successful the treatment is likely to be.
 
 

?       Fits do not cause any deterioration in intelligence, or a change in temperament.  Owners often worry that the heart will be damaged by the apparent violence of the heart-beat during and after a fit, but there is no evidence to support this fear.
 
 

?       Normal activity need not be restricted;  the fits will occur during periods of relaxation or sleep, not when the animal is excited or overactive.  There have been Olympic athletes who were epileptic , and they were able to train and perform successfully without fear of fits.  Working dogs such as Guide Dogs and Police Dogs can continue to work satisfactorily with primary epilepsy.
 
 
 
 

As you will now see epilepsy is a complex problem.  This leaflet cannot hope to cover all of the questions you may have, however by reading it you should now have developed a good basic understanding of the most important aspects.  There will be individual point, pertinent to your dog that you may like to discuss, or times when the burden of worry seems especially great.  This is what your vet is here for; to answer your questions and help you over any difficult periods, as well as for the treatment of your dog.
 
 
 
 

THE MANAGEMENT OF FITS
 
 

Keep these sheets in a handy place for quick reference and use during and after fits.
 
 

Before a Fit

If experience has shown that your dog has a long aura before a fit, it may be possible to give some medication during this phase to prevent or lessen the severity of the actual seizure.  This should be worked out by your vet before-hand who will fill in the details below.
 
 

Medication to be given during the Aura
 
 

If you feel a fit is coming on keep the dog active by walking it around, but keep it away from dangers, and get these sheets out ready for use.
 
 

During a Fit

THERE IS LITTLE THAT AN OWNER CAN OR SHOULD DO WHEN A DOG HAS A FIT.
 
 

•       Ensure that it does not damage itself:

e.g. by falling downstairs, off furniture, or into a pond, or burn itself near a fire.  Moving a dog during a fit can be done by throwing a blanket or coat over it first and then gathering it up, or if afraid to do that pushing the covered animal with the foot.
 
 

•       There is no need to insert a wedge between the teeth:

Since dogs seldom bit their tongues when fitting, and if they do the injury is not usually severe.
 
 

•       Never try to give any tablets during a fit.
 
 

•       Keep young children and other animals away until the dog is fully recovered.
 
 

After a Fit

As the animal recovers and wanders round without full vision, it may be necessary to shut it in a room with as few obstructions in it as possible, until the whole of the brain has recovered its normal activity.  This POST-ICTAL period is very variable - sometimes it lasts a few hours or so, and sometimes it is completely absent.  This stage can seem very distressing, but there is little you can do to shorten or alter it. It usually ends with the animal tiring and lying down to sleep.  The sleep seems natural, and when the animal wakes it is, in all respects, normal.

        A dog is totally unaware of its surroundings during a fit and, as it recovers, there is often a stage when it is on its feet but does not yet recognise the people around it.  DURING THIS PHASE THERE IS A DANGER THAT A NORMALLY GENTLE ANIMAL MAY BITE SOMEONE.  It is important that you realise this both for your sake and for the sake of children or visitors.
 
 

Fill in the 'record of fits' sheet as soon as possible and as accurately as you can after the fit.  Inform your vet so that he can keep his records up to date, and advise you of any change in the medication.  If your dog has one fit after another for many hours it could be in STATUS EPILEPTICUS - INFORM YOUR VET STRAIGHT AWAY so that he can take action.
 
 

In the Long Term
 
 

The animal's life style probably need not be drastically changed.

Fits normally occur during relaxation so there is no need to curtail exercise.  The dog should not be left alone with other dogs, until their reaction to it at the time of a fit can be seen - they may attack.
 
 
 
 

The most important thing for you to do is ensure that your dog gets its medication regularly without fail.