Epilepsy is a condition in which a dog has recurrent seizures but there is no structural brain lesion that can be found. The brain is structurally normal but functions abnormally for some unknown reason. Nobody knows exactly what causes epilepsy. It may be due to some little understood biochemical problem involving the neurological system or it may be due to some kind of intrinsic anomaly of the brain. Epilepsy is very common in dogs (much less so in cats) and accounts for 40 to 80% of seizures in these animals. The problem will usually first become apparent while the dog is young (under three years of age for the first seizure) and will continue for life (if an older dog has a seizure for the first time it is more likely to be due to some other disease). Many breeds of dog have a predisposition towards epilepsy, probably due to some form of genetically inherited factor. Breeds often affected by epilepsy include the Beagle, Border collie, Labrador retriever, Boxer, Cocker spaniel, German shepherd, Golden retriever, Irish setter, Keeshond, poodle, St Bernard, Siberian husky and Welsh corgi.
A typical epileptic seizure will have four distinct phases. The first "prodromal" phase is often overlooked since signs are very mild and variable but the dog may seem a little confused or "not with it"; some pets exhibit anxious behaviour or try to stay close to their owner; this stage can last a few hours. The second phase or aura follows this, but is a very short phase and difficult to distinguish from the first; again a change in behaviour is the sign seen during this time.
The seizure itself follows the aura phase. Seizures involve uncontrolled muscular spasms and vary in severity and duration. Seizures are classified into two types depending upon their severity. These two types are the grand mal seizure which affects the whole body and in which the dog totally loses control of itself, and the petit mal where the dog retains some control over its body but may experience muscle spasms or reduced mental function exhibited by behaviour such as staring vacantly into space. Typically in a "grand mal" type of seizure the dog may stagger or appear to be disorientated, its facial muscles may begin to spasm, then other muscles become stiff, the dog may chomp its jaws, salivate copiously, bladder and bowel control may be lost and the dog may make a paddling motion with some or all of its limbs in an uncoordinated fashion, sometimes the dog cries out and this is very distressing for the owner to observe. These "fits" tend to last about 3 minutes or so (longer ones are more serious).
The fourth or post-ictal phase occurs after the actual fit and may involve a period of disorientation or confusion when the dog may pace aimlessly and seem confused or distressed. There may be an increase in thirst and hunger during this stage which can last as long as 24 hours but typically lasts around 3 hours.
Sometimes dogs will just have "petit mal" seizures which may involve local muscle spasms, staggering or strange vacant behaviours.
If one seizure ends only for another to begin and this continues with no recovery between the "fits" it is a very serious condition called status epilepticus and urgent medical treatment is required. If you believe that this is happening to your dog call your veterinary practice day or night. Dogs can die if this condition is not treated!
If you are present when your dog has an epileptic fit it can be a very frightening thing to see, especially the first time it happens!. There is actually very little that you can do to help your pet. It is important to make sure that your dog is not in a situation where it may hurt itself so make sure it is on the floor not on a high surface such as a chair which it could fall from. Ensure that there are no sharp objects or heaters or hot drinks around which could burn your dog if it knocks into them while it is fitting and thrashing around. Do not try to open the dog's mouth or get the tongue out as you may injure the dog or get badly bitten (the muscle contractions are strong and your dog cannot control them) it is rare for dogs to choke on their tongues while fitting although this is a common belief! It may be helpful to talk quietly in a reassuring voice to your pet during the seizure, but do turn off loud music or take frightened noisy children out of the room, dim the lights if possible and keep any form of stimulation to the minimum. After this all you can do is wait for the seizure to be over! Dogs do not die after a seizure although it often looks frighteningly as if they have at the end of grand-mal seizures when it can appear as if the animal stops breathing for a while! However if seizures are clustered and occur one after the other (status epilepticus) this is very serious and requires urgent medical treatment. After the seizure it is wise to make a note of the date, time, severity and duration of the seizure so that you can see any patterns in seizure occurrence. It is also a good idea to try and remember what your pet was doing before the seizure occurred in case you can identify any precipitating factors. Keeping a "seizure diary" will help to allow you and your vet to monitor the response of your dog to any medication which is given.
Most owners tend to panic when they witness their pet having a seizure for the first time. Do your best to remain calm! It is sensible to call your vet, and he or she will almost certainly arrange for your pet to be seen very quickly. However the nature of epilepsy is such that by the time you get to the practice your dog will often be just about back to normal. The vet will examine your pet and will pay particular attention to its cardiovascular system, temperature and any neurological signs. It is most likely that in the truly epileptic patient everything will be normal. A blood sample will probably be taken to check for biochemical imbalances and signs of other diseases which may be relevant to the seizure. A sample of urine may also be requested. Your vet will certainly let you know if any abnormalities are discovered, but the likelihood is that everything will be normal! Very rarely your vet may suggest more specialized tests such as an MRI or CT scan which could show up a problem such as a brain tumour. If no sign of any other problem is found then a diagnosis of idiopathic epilepsy can be made.
In patients with epilepsy vets aim to control the disease because it cannot be cured. If your dog has a mild seizure less than every 8 weeks or so it is probably wise not to give it any drugs since this not a serious problem and the potential side effects of the drugs are more of an issue than the disease in this situation. If seizures are severe or occurring frequently then a number of drug treatments can be tried. The drugs most commonly used in canine epileptic patients are phenobarbitone and potassium bromide. These drugs are given by mouth and require some time to reach a steady concentration in the body before they will be effective in controlling the seizures. With phenobarbitone this takes about two weeks to achieve. Your vet will need to take regular blood samples to check the levels of these drugs in the blood and to check that the liver is coping with the medication. If any problems are found then the drug dose may need to be altered or your dog may need to be referred to a veterinary neurologist. The aim of treatment is to reduce the frequency and severity of seizures to an acceptable level, it will not make them completely cease! Medication will often be required for life in truly epileptic patients. Other drugs which are sometimes used in epileptic dogs include diazepam and phenytoin. The major side effect of these drugs is hepatotoxicity (liver damage) and your vet will want to monitor your pet's liver function with regular blood tests (usually every 6 to 12 months)
An epileptic dog can generally live a normal life, however it is wise to take a few sensible precautions with these pets:
Do not to allow your dog to swim in case it has a seizure and drowns.
You will need to control your pet's diet as the anti-epileptic drugs often cause a dog to gain weight.
It is not a good idea to allow your epileptic dog to breed as it may pass on the problem to its offspring.
Neutering females may be helpful since hormonal changes around oestrus may increase the likelihood of a seizure.
Never stop giving your dog the anti-epileptic drugs suddenly as this rapid withdrawal often causes severe seizures; if you wish to try to stop the treatment your dog will need to be gradually weaned off the drugs.
If your dog needs veterinary attention for any other problems it is best to ensure that the vet is aware that your dog is an epileptic as some drugs will increase the likelihood of a seizure and should not be given to these patients.
Remember that epilepsy can hopefully be controlled but cannot be cured. Each individual epileptic dog will be different and the drugs which work for one may not work for another. Some dogs will just experience one seizure and never have another one, other dogs will have seizures at a reasonably regular intervals and some unfortunate animals will have severe epilepsy with seizures at very frequent and unpredictable intervals. Very occasionally a dog will develop severe cluster seizures or status epilepticus and die. If your pet is an epileptic it is important to find a vet you like and trust so that you can build up a long term working relationship and keep your pet's condition under control. Unfortunately epileptic animals often get more frequent or more severe fits over time so as your dog gets older it may need more aggressive treatment to control the problem.
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