Key points
- Do not change or stop treatment without talking to your vet.
- Bring your pet for a check-up at least once a year.
If a seizure lasts 5–10 minutes, or there are 3 or more seizures in a day, contact a vet urgently.
You live with epilepsy, not because of it. Animals that are treated properly lead full lives, with only the occasional "bad" day. Enjoy the good days and enjoy your pet. Yes, your pet has a serious condition, but do not let it take over your life.
Talk to your vet
Your vet knows your pet's health best: what it has had in the past, what it has now and which medicines have been used. Learn about the condition and do not be afraid to ask questions. If it is not clear why certain tests are needed or why a particular treatment has been chosen, your vet should explain how it will help your pet.
There is a lot of information online, but it is not worth trusting blindly unless it comes from a reliable specialist who knows the field. Show your vet what you have found. They will help you tell useful advice apart from advice that is unnecessary or could even harm your pet.
What is epilepsy?
Epilepsy usually means recurring seizures. For various reasons, an animal may have a seizure only once in its life. If seizures keep coming back from time to time, that is epilepsy.
Seizures are a sign of brain disease, in the same way that a cough is a sign of lung disease. Anything that damages the brain can cause seizures. Depending on whether a cause is found, there are two forms of epilepsy:
- symptomatic (secondary) epilepsy, when the cause of the seizures is found, for example a brain tumour or a stroke; the seizures are then a sign of that underlying disease;
- idiopathic (primary) epilepsy, when the animal is fully investigated but no cause for the seizures is found.
Most animals with idiopathic epilepsy have an inherited form of the disease, which usually appears between 1 and 3 years of age. Dogs of certain breeds are predisposed to it.
How common is it?
Epilepsy is one of the most common neurological disorders in dogs, but exactly how common is not known. Some data suggest it affects 4% of dogs, others up to 14%. It is less common in cats and other animals because they do not usually have the inherited form.
Can a seizure be predicted?
Nobody knows when an epileptic animal will have a seizure. In some animals seizures recur very regularly, in others only in certain circumstances, for example after stress or when the weather changes. Even when you know the circumstances of previous seizures, it is hard to predict when the next one will happen. Unfortunately, in most epileptic animals no pattern can be found.
How idiopathic epilepsy is diagnosed
Idiopathic epilepsy is a diagnosis of exclusion: the vet looks for other causes of seizures, and if none are found, idiopathic epilepsy is diagnosed. How the investigation goes depends on the clinical signs, the clinic and the owner's circumstances.
To someone without experience, a faint or an episode of weakness can look exactly like an epileptic seizure. That is why your vet needs a detailed description of what you saw during the episode: it helps them decide what type of seizures your pet is having.
As soon as you can after a seizure, write down everything you saw in detail. If possible, film your pet during the seizure and show the video to your vet or a neurologist.
To rule out certain diseases, your vet will carry out several tests. For some of them, they may refer your pet to a neurologist. Even if the animal is the typical age for idiopathic epilepsy, it cannot be called primary epilepsy until the other tests have been done. A study by Podell (1995) showed that more than a third of dogs aged 1–5 years had a clear cause for their seizures. So a dog with epilepsy should have every possible test to look for a cause, although the cost of these investigations also has to be taken into account.
Electroencephalogram (EEG). An EEG is very helpful in diagnosing epilepsy, but it is harder to perform on an animal than on a person. If the EEG shows changes, you can be confident that the episodes are epileptic seizures and predict where the damage is. The problem is that EEG changes, like seizures, come and go, so a recording taken between seizures may not pick them up. It is also difficult to record an EEG in an animal that is awake, so sedatives are often used to keep it still. Weighing up the pros and cons, epilepsy is usually diagnosed from the clinical signs, without an EEG.
Other essential tests
Liver disease can cause seizures, and epilepsy medicines can damage the liver. That is why blood tests to check liver function are recommended both at the initial diagnosis and at each annual check-up.
Depending on the animal's age, the type of seizures and the results of the neurological examination, your vet may suggest further tests. Standard X-rays can show whether the skull bones are intact, but not the brain itself. To assess the brain, magnetic resonance imaging (MRI) or computed tomography (CT) is recommended. These scans are not yet available for animals in Lithuania, but they will be in the future. If needed, the animal is referred to neurologists abroad. These scans can detect problems such as brain tumours or hydrocephalus, which are among the most common causes of seizures and can sometimes be cured.
Seizures can also be caused by inflammation of the brain (encephalitis). In dogs, encephalitis is most often caused by the distemper virus, which is why regular yearly vaccination is recommended. If an unvaccinated dog starts having seizures, your vet will recommend a rapid test for canine distemper.
What are seizures?
Seizures are caused by a "storm" of electrical impulses in the brain. Healthy brain cells communicate with each other through electrical and chemical signals. A signal can be excitatory (it activates the next neuron) or inhibitory (it holds it back), and the brain keeps a precise balance between the two. If the balance tips towards excitation, too many cells fire too strongly and a seizure begins.
This is about the excitation of individual neurons, not about how excited your pet gets when you come home. In fact, seizures most often happen when the animal is at its most relaxed or asleep. Only occasionally do they occur during play or emotional excitement.
An EEG records this excessive excitation of nerve cells as a sharp electrical spike. The "storm" causes the changes in behaviour and movement that we call a seizure. Seizures are divided into several types according to the origin and location of the problem.
Types of seizures
There are two main types of seizures:
- generalised, where the "storm" of electrical impulses starts across the whole brain at once;
- focal (partial), where electrical activity increases only in one small part of the brain.
Your vet may never see a seizure, so they will classify it based on what you tell them. Describe to your vet or neurologist as accurately as you can what you saw during the seizures.
Generalised tonic-clonic (grand mal) seizures
Generalised seizures are further divided into two subtypes: major motor seizures (grand mal) and absence seizures (petit mal). Classic seizures are grand mal, often called tonic-clonic. They usually have three phases, although not all of them are always equally obvious:
- the aura (prodromal phase);
- the seizure itself (ictus);
- the post-seizure phase (post-ictus).
Seizures most often happen when the animal is completely relaxed and in a quiet place. Of course, they can start at any time. But if you notice that seizures start while your pet is moving or very excited, heart problems or low blood sugar may be suspected.
Aura. Just as some dogs can sense when their epileptic owner is about to have a seizure, some owners can sense when their dog is about to have one. The aura (prodromal phase) is a clear change in behaviour that signals an approaching seizure. Most often the animal seems very low or restless: it may seek its owner's attention or, on the contrary, hide. The aura is often confused with the start of a focal seizure.
Tonic phase. A typical tonic-clonic seizure starts with intense muscle stiffening. Usually the animal falls onto its side, stretches its legs out stiffly in front and throws its head back. As soon as the seizure starts, the animal loses consciousness, although its eyes often stay open. Sometimes a dog whines, howls or barks, and the muscles of the face twitch. These sounds are involuntary and are definitely not a sign of pain. The animal usually drools heavily and may urinate, defecate or empty its anal glands. This, too, is completely beyond its control, because it is unconscious during the seizure. The tonic phase is very short, under 30 seconds.
Clonic phase. After the tonic phase come rhythmic movements: usually the jaws move and the legs make paddling or running movements. During the seizure the animal breathes irregularly, so its tongue may turn blue.
Even if the seizure seems to go on forever, it actually lasts no longer than 2 minutes. If a seizure lasts much longer, there is a risk that the animal will go into a continuous seizure state (status epilepticus). In that case, contact a vet immediately.
Behaviour after a seizure
After a seizure, the animal may lie still for a while before getting up again. Some dogs jump up straight away and behave as if nothing has happened, but most need time to recover. During this time the animal often seems blind and disoriented, may wander around the house and bump into things in its way. Sometimes it is very hungry and will eat any food it finds.
Very rarely, some animals become aggressive after a seizure, especially if they are tied up. Although this is rare, it is important to recognise it in time, especially with a large-breed dog in a home with small children. Post-seizure behaviour returns to normal within a few hours, and the dog is itself again.
Not all seizures follow the pattern described above. Some animals have no aura and the seizure starts suddenly. Some dogs jump up straight after a seizure and behave as if nothing has happened, while others stay disoriented for several days. Some have only tonic stiffening (rigidity) during a seizure, others only clonic movements. Very rarely, the animal simply falls onto its side and lies still. This kind of episode is more typical of absence seizures (petit mal), but it can also happen with convulsions.
Cluster seizures and status epilepticus
Most seizures are single and very short, but sometimes things are much more complicated. Large-breed dogs are prone to cluster seizures: the dog recovers from one seizure, and a few hours later has another. Between seizures the dog does not fully recover. Then comes another, and another. Sometimes this turns into a seizure that does not stop, a state called status epilepticus. Occasionally status epilepticus starts without any warning: the animal begins to seize and does not stop.
Cluster seizures and status epilepticus are emergencies that need urgent veterinary care.
Effects of seizures
Most seizures are short, and an animal that is treated properly can lead a full life. Even so, seizures are a serious disorder and can damage the brain, and this damage builds up over time. The main consequence of a short seizure is that another seizure is likely in the future. That is why epilepsy tends to get worse over time, especially if it is not treated.
If a seizure lasts longer than 30 minutes, serious and permanent brain damage is very likely. This can show up as personality changes or forgetting things the animal has learned, such as obedience and commands. Sometimes these seizures lead to a coma. The intense muscle activity drives body temperature up sharply, and the animal breathes irregularly. Seizures can occasionally put the body under so much stress that the heart fails and the animal dies. Fortunately, this is very rare.
Absence seizures (petit mal)
This subtype of seizure is typical in people. It differs from grand mal in that the brain experiences a wave of inhibition of electrical impulses rather than excitation. Whether animals really have absence seizures has not been fully established. In animals, what looks like petit mal is often actually a focal seizure.
Focal seizures
In a focal (partial) seizure, the "storm" of electrical impulses starts in one isolated part of the brain. It may stay local or spread across the whole brain and cause a generalised seizure. So what looks like an aura is sometimes actually a focal seizure turning into a generalised one. If an animal has this type of seizure, damage in a specific area can reasonably be suspected. Tests are then carried out for conditions that cause localised brain damage, such as infections or tumours.
Simple focal seizures start in the areas of the brain that control movement of a particular part of the body. Most often the facial muscles twitch and the animal blinks, often on one side of the face only. If the focus spreads, other parts of the same side of the body are affected, for example a front leg starts to twitch. Usually the animal stays conscious during this kind of seizure and looks for its owner, not understanding what is happening. The seizure may end there or turn into a generalised seizure: the animal then loses consciousness and a classic tonic-clonic seizure begins.
Complex focal seizures start in the areas of the brain responsible for emotions and behaviour (the temporal regions). During this kind of seizure the animal's consciousness is affected, so it behaves strangely: it may run without stopping for dozens of kilometres, repeat aimless actions or even behave aggressively. In other cases body functions are disrupted, causing diarrhoea or vomiting. Like all epileptic seizures, complex focal seizures are short.
Most dogs that behave aggressively or strangely have behavioural problems. But if this behaviour happens only rarely and the dog sometimes also has generalised seizures, complex focal seizures may be suspected and treated accordingly. People who have these seizures experience hallucinations. Some dogs have "fly-catching" episodes, snapping at imaginary flies around their head. These may be hallucinations, but it is hard to say for sure.
What else can look like a seizure?
Some conditions can be mistaken for epileptic seizures:
- dogs with inner ear inflammation can have episodes that look like seizures;
- dogs with heart disease can have fainting episodes;
- sleep disorders, where the animal collapses or makes intense leg movements while asleep.
Your description of the episode will help your vet tell these conditions apart.
Treating epilepsy
Ideally, the cause of the epilepsy would be removed so that the animal never has another seizure. If the epilepsy is symptomatic, treating the underlying disease, for example removing a brain tumour, is sometimes enough to cure it. Far more often, though, the diagnosis is idiopathic epilepsy, where the cause remains unknown. Sometimes a cause is found, but the brain is already too badly damaged, the changes are permanent and the seizures keep coming back. In that case, medicines to control the seizures are prescribed.
What treatment aims to do. Epilepsy medicines do not cure the condition. They help control the seizures, so treatment is lifelong. The goal is to reduce how often seizures happen and how severe they are. Above all, it is important to prevent cluster seizures, which can be life-threatening. Even with ideal treatment, seizures will still happen from time to time. If they are infrequent, short and mild, and the medicines cause no side effects, the treatment is considered successful. With proper treatment, seizures can be controlled in two thirds of epileptic animals, but in a fair number of animals they are very hard to manage.
Treating epilepsy takes a great deal of patience. Medicines affect each animal differently, so finding the right treatment takes time, and doses may change with age. After treatment starts or a medicine is changed, it takes a while for the drug to reach its full effect. It is very hard to watch your pet suffer seizures, but if your vet tells you to wait, there is a reason: there is no way to speed up how the body absorbs the medicine.
Seizures can recur even on medication, so it is important to keep track of how often they happen and how long they last, to judge whether the treatment is working. Your vet will suggest keeping a calendar of seizure dates, time of day, duration and severity.
All epilepsy medicines dampen excitation in the brain so that seizures happen less often. The main medicines used in dogs are phenobarbital, potassium bromide and diazepam. They are given on their own or in certain combinations. Dampening brain activity in this way often causes side effects, such as drowsiness and increased appetite.
When does treatment start?
Before starting treatment, it is necessary to weigh up which risk is greater: untreated seizures or the side effects of the medicine. In general, if seizures happen more often than once every couple of months, the risk of brain damage and of the condition getting worse is high enough to start treatment. If the animal has had cluster seizures or status epilepticus, treatment is strongly recommended, because these are life-threatening. The animal's general health, home environment and the family's finances also need to be considered.
Will it ever be possible to stop treatment?
For most epileptic animals, treatment continues for life. Even so, some animals do "get better". This most often happens when the cause of the seizures is identified precisely and removed, but sometimes animals with idiopathic epilepsy are lucky too. Since seizures cannot be avoided completely even with treatment, the decision to stop medication needs careful thought. Usually doses are reduced once there have been no seizures for several months.
The body gets used to the medicine, so it must never be stopped suddenly: this can trigger very severe and prolonged seizures. Doses are reduced very gradually, and at the slightest sign of a seizure the full dose is restored. Once again, the owner will need patience.
Never stop your pet's prescribed treatment without talking to your vet.
