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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.


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.


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.


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.






Flower Essences


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”  


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.