What is epilepsy?
There are many causes of seizures but the absence of an
identifiable cause is what characterises what is known as
“idiopathic” or “primary” epilepsy.
There is no definitive test for epilepsy and any diagnosis is
tentative. One seizure alone does not result in a diagnosis of
epilepsy. The seizures must be recurrent for this diagnosis to
be at all reliable and it is unlikely that treatment for epilepsy
would be recommended until at least two episodes had
occurred.
Some breeds seem to be predisposed to canine epilepsy, among
them, the Belgian Terveuren, German Shepherd, Golden Retriever and
Border Collie. It has been suggested that between 1 – 6% of
pure bred dogs have a seizure problem
Most instances of idiopathic epilepsy initially occur when
the dog is between 1 and 5 years of age although it is increasingly
common for dogs as young as 6 months to be diagnosed with primary
epilepsy. Dogs that start fitting after the age of 5 years
will almost certainly have a secondary condition causing the
fitting.
What does a seizure look like?
The vast majority of seizures occur when the dog is at rest
or sleeping. It is rare for dogs suffering from primary
epilepsy to have a seizure when they are active. For this
reason it is quite possible for a dog to have an active
life. There are four phases of a seizure
Prodomal phase – abnormal behaviour possibly lasting for
several hours
Aura – a short phase of abnormal behaviour immediately prior
to the seizure. The dog may become aloof or clingy, may appear
vacant or twitchy.
Ictus – the actual seizure lasting approximately 2 – 5
minutes. The dog will usually be unconscious, champing its jaws,
thrashing its limbs, its body rigid. It will salivate and/or
foam at the mouth and may urinate and/or defecate.
Post Ictus/Ictal – dogs are dazed, disorientated and show
abnormal behaviour immediately after the fit. For several
hours or even days the animal may pace about, fail to recognise
familiar people and the senses may be impaired with hearing and
sight being the last to return. Owners often find the post
ictal phase more distressing than the fit itself.
Types of seizure
Generalised seizure: Tonic-clonic (Grand mal or mild) In
the Grand mal seizure, the tonic phase desribes the animal falling
and losing consciousness. This can last for 10-30 seconds
before the clonic stage which involve the paddling of the limbs and
chewing/champing. Other signs include salivation, urination
and defecation.
Petit mal seizure: A brief duration of unconsciousness,
the animal may become floppy and may stare blankly. Also known
as Absence Seizure.
Partial seizure: also known as focal seizures, the
movements are restricted to one area of the body, e.g. one limb,
turning head or body to one side, facial twitches. Partial
seizures can progress into a generalised tonic clonic
seizure.
Complex partial seizure: seizures are linked with
bizarre behaviour repeated during each seizure. Examples
include chewing, fly-biting, aggression, hysterical running
etc. Although the animal may not lose consciousness, there may
be a lack of awareness which may last minutes or
hours.
Cluster seizure: several seizures within a 24 hour
period with periods of consciousness (however brief) in
between.
Status epilepticus: a life threatening condition which
involves one continuous seizure of 30 minutes or more, or several
consecutive seizures with no periods of normal consciousness in
between. Veterinary intervention is required
immediately.
What to do if your dog has a
seizure
If your dog has a seizure is can be a frightening
experience. Firstly make sure that the dog cannot injure
itself for example by falling down the stairs. If you have other
dogs in your household, they should be moved away as, rarely, other
dogs will attack a dog during or after a seizure. Reduce noise
and darken the room, then step back and observe. Do not put
your hands near the dog’s mouth as you may be bitten. It will
be important that you can describe the episode accurately to your
vet so make notes and time the event. A seizure is a great
deal more distressing for the owner than for the dog. It is
possible that, following a seizure, the dog may be disorientated
and irritable. Some dogs become aggressive immediately
following a seizure. Take care when approaching the
dog. Often, following a seizure, the dog will be hungry and a
high energy, nutritious “snack” can be given.
Diagnosis
A definitive diagnosis of idiopathic epilepsy is rarely
possible and it is important to eliminate possibility of underlying
disease. It is usual for a full blood work up to be carried
out together with a neurological examination, serum chemistry
profile and urinalysis. In addition an MRI scan may be
considered, particularly if abnormalities are detected during the
neurological examination.
Causes of seizures
Extracranial (causes from outside the head ) including
liver disease, poisoning, hypoglycaemia, kidney disease, heart
disease, low blood calcium
Intracranial (causes inside the head) including
hydrocephalus, head injury, brain tumour, distemper, protozoal
diseases etc
Seizures which have an identifiable cause are known as
secondary (SES) where the abnormality is structural or
reactive (RES) where the abnormality is the result of an external
factor.
Seizure Threshold
All dogs have a seizure threshold, beyond which certain
conditions may result in a seizure. Dogs with idiopathic
epilepsy may be described as having an abnormally low seizure
threshold. The seizure threshold may be lowered by external
factors. Infections, metabolic disturbances, drug
administration and stress can all lead to seizures in an otherwise
well-controlled epileptic dog. Commonly used drugs such as
ACP (acetylpromazine) which is used as a “pre-med” before surgery,
is known to lower the seizure threshold and should be used with
caution in epileptic dogs. It is also known that the varying
hormone levels in the oestrus cycle can exacerbate fitting and it
is often recommended that affected bitches are
spayed.
These must be considerations when thinking about the
management of your dog. You should research the effects of
vaccination and worming on your epileptic dog and try to eliminate
any chemicals or other external factors which may lower your dog’s
seizure threshold. Clearly this must include a close
examination of your dog’s diet.
Treatment
It is now understood that with each seizure a dog has the
brain can “learn” to have another seizure. This is a process
called “kindling” and can cause seizures to become ever more
frequent and more serious. For this reason, early treatment is
recommended, to prevent the seizures from becoming
uncontrollable. It is much easier to gain control of the
seizures at an early stage. Treatment will probably be
recommended for dogs who have more than one seizure a
month.
Anti-epileptic treatments do not cure epilepsy. The goal
is to control the seizures. The same treatment is used whether the
epilepsy is primary or secondary. It is unlikely that the
seizures will stop completely. The aim is to balance the need
to reduce the seizures with the need to limit the side effects of
the drugs. All anti-epileptic drugs have side effects, some
of which are life threatening in themselves. What
constitutes a tolerable level of seizures will differ according to
how well the owner copes with the episodes. Most
anti-epileptic treatment needs to be continued for the life of the
animal, however, in a small number of cases, the medication may be
gradually withdrawn.
Important note: Anti-epileptic medication must never be
discontinued without veterinary advice. If drugs are withdrawn
too quickly, breakthrough seizures will occur and the ability to
regain control over the seizures may be permanently
compromised.
Common Drug treatments
Phenobarbitone (or phenobarbital) – one of the most commonly
prescribed drugs (Epiphen). It is successful in a large number
of cases and an improvement is seen in a short period of time (less
than 2 weeks). It has the advantage of staying in the body
long enough so that it only needs to be given twice a day. The
drug must be given at 12 hourly intervals so that the levels in the
blood do not fall and cause a seizure. When the medication is
first started most dogs have side effects of a sedative
nature. Dogs may be unsteady on their feet and generally
sedated however, most become tolerant to the side effects within a
few days/weeks. It is important to continue with the
medication even though the immediate side effects may be
distressing. The main side effect with Phenobarbitone is the
damage it does to the liver. Over time many dogs develop liver
damage and, although some dogs never develop any liver problems, it
is important that regular liver function tests are carried
out. Dogs will demonstrate increased appetite and
thirst.
Primidone (Mysoline) is metabolised in the liver resulting in
the production of phenobarbitone. The effects of Primidone
are similar to the effects of Phenobarbitone, however, it is more
expensive to administer.
Potassium Bromide (or Sodium Bromide)
Bromide has been used to treat epilepsy for hundreds of years
although has been shown to cause psychological problems in people,
these issues are not common in dogs. Bromide has a very long
half life which means it takes a long time for the body to
eliminate the drug, however, it also takes longer to become
effective. Bromide can cause an upset stomach and should
be given with food. Potassium Bromide is eliminated by the
kidneys and so has none of the adverse effects on the liver
experienced through the use of Phenobarbitone. Bromide can
also cause sedation when it is first used and dogs quickly become
tolerant to its effects. As Bromide is replaced by chloride an
increase of salt (sodium chloride) or other sources of chloride in
the diet can cause the bromide levels in the blood to
fall. Dogs being treated with Bromide should have a consistent
diet. Dogs may have increased appetite and
thirst. Potassium Bromide is sometimes used as a combination
therapy with Phenobarbitone. This combines the benefits of the
quicker acting and reliable Phenobarbitone with the ability to
reduce the amount of Phenobarbitone needed to control the seizures
(and thus limit the side effects) through the addition of the
Potassium Bromide.
Diazepam/valium
Whilst diazepam is a very effective anti-seizure drug, it has
a very short half-life (of only a few hours) and becomes less
effective over time. It is, however, commonly used to stop a
seizure in progress. Diazepam, administered rectally, is often
used to halt a severe seizure in progress, with the aim of
preventing status epilepticus.
Other drugs less commonly used are prescribed usually where
the main treatments have been unsuccessful. They
include:
Gabapentin (Neurontin)
Propentofylline (Vivitonin)
Levetiracetam (Keppra)
Alternative Therapies
Some dogs respond well to alternative therapies, however,
whilst significant improvements may be experienced, a severe
epileptic dog will nearly always require drug therapy as
well. Richard Allport, a well-known veterinary surgeon
specialising in natural therapies, states that 99% of the animals
he treats need to remain on conventional treatment.
Acupuncture
Massage/Acpressure
Vitamins/supplements
Herbs
Aromatherapy
Flower Essences
Diet
Many owners of epileptic pets report real benefits when
switching to a natural feeding regime. Caroline Levin explores
this factor in some depth in her book “Canine epilepsy – An owners’
guide to living with and without seizures”
Breeding
The issues surrounding epilepsy and breeding are complex and
emotive. The lack of a test for the condition and fact that
epilepsy can be carried without the carrier becoming affected,
together with late onset of seizures can all make the decision
whether to exclude a particular dog, parents or littermates from a
breeding program a difficult call.
My experience
When Darcy had is first fit at the age of 7 months I was
shocked. My vet immediately said “he has epilepsy” but I
didn’t want to believe it. I didn’t want to medicate so went
away and started my research.
He had another fit a month later – but still I didn’t want to
believe it. I had lots of tests done. My vet thought I
was mad but I insisted… He didn’t have an MRI scan because the
neuroexam was clear and I knew any diagnosis from the scan would be
unlikely to change the recommended treatment.
In February, three months after his first fit, the big one
came! He had a cluster of dozens of fits throughout the
night. When we got up in the morning he was a mess. Darcy
was blind and disorientated. He paced about helplessly bumping
into things. I cried. It was very
distressing.
It took Darcy over a week to recover from these fits and I
knew he had to go on medication. I had done my research and
asked for him to be put on a combination of Phenobarbitone
(Epiphen) and Potassium Bromide (Genitrix). This would provide
a balanced of good seizure control whilst minimising the liver
damage that could be caused by high doses of
Phenobarbitone.
Darcy was put on 90mg of Epiphen twice daily and 325mg of
Genitrix twice daily. He did suffer the usual side effects of
the medication at first. He was floppy and
bleary-eyed. He fell over and couldn’t walk up the
stairs. But these problems passed. He did get back almost
to normal. I know that, without the drugs, he would have been
a bit more co-ordinated but most people wouldn’t have known the
difference. He went on to win Obedience competitions and was
the keenest, most enthusiastic dog I have ever owned.
Epilepsy is a devastating condition and it is heartbreaking
to see your much-loved pet go through all that. The side
effects of the medication and the unpredictability of the fits can
make it all seem too much. My only advice is to look to others
for help and support. It is out there, if you ask for
it. Don’t give up just yet. Try to work it through and,
if you eventually decide that your dog’s quality of life is too
badly compromised to carry on, at least you will know that you did
everything humanly possible.
You do need a good relationship with your vet but you also
need to be well-informed as few vets are expert in Canine
Epilepsy. You need to ask for relevant tests and not assume
that your vet will do everything necessary. Even if your dog
is put on medication, you need to ask for regular tests to ensure
that therapeutic levels are maintained and that there are no
adverse effects.
Many people have had epileptic dogs that go on to live a
normal life, even if it is on daily medication and it eventually
died of something completely unrelated!
Please note that this article reflects my own opinions, based
on extensive research and experiences. If you act on this
information, you do so at your own risk. Please read my
disclaimer.
Remember - always consult your vet.
