Epilepsy in Dogs

Clients whose pets have epilepsy have consistently shared positive experiences with us.

If you notice any of these symptoms, consult a veterinarian, ideally a veterinary neurologist.

What is epilepsy?

Epilepsy is a chronic condition that causes repeated seizures (these include a whole range of symptoms, but typically convulsions while lying on the side, with loss of awareness). It is the most common chronic neurological disorder in dogs - we don't have statistics for Croatia, but in the UK 1 in 130 dogs are affected, i.e. 0.6-0.7% of dogs.

In most cases, epilepsy is a lifelong disease. Some dogs have a seizure once a year or less, while others have seizures several times a day, depending on the type and severity of their condition.

What happens during a seizure?

A seizure occurs as a result of abnormal electrical activity in the brain that causes sudden, short-term changes in the dog's behavior (most often loss of body control).

How do I know if my dog is epileptic?

Your veterinarian may suspect epilepsy if a dog has at least two unprovoked seizures more than 24 hours apart. Seizures can be difficult to distinguish from other health problems. Describe what happened in detail to your veterinarian and, if you can, record an episode on your phone.

Characteristics of epileptic seizures

The three main symptoms of epileptic seizures are:

• Loss of voluntary control, often seen as convulsions, tremors or muscle jerks
• Episodes that start and end abruptly
• Seizures that look similar each time and follow a recurring pattern

Are there different types of seizures?

There are several types of epileptic seizures, but the way they affect one dog may differ from the way they affect another. Some dogs have more than one type of seizure, and not all seizures involve convulsions. Most epileptic seizures have a similar pattern:

• They happen suddenly, often without warning
• They last a short time (often just a few seconds or minutes)
• They stop on their own

Injuries can occur during a seizure, although most dogs are not injured. If your dog has not already been diagnosed with epilepsy, contact your veterinarian.

Below are the names of the different types of seizures, along with descriptions of what happens during each type of seizure:

• Focal seizures (jerking, blinking, drooling or changes in behaviour) begin in a specific area on one side of the brain. Their signs depend on where the abnormal electrical activity begins and what that part of the brain controls.

Focal epileptic seizures can manifest as:

• episodic motor signs, such as facial twitching, rhythmic blinking, head shaking or repeated contractions of a limb; or
• autonomic signs, such as excessive salivation, vomiting or dilated pupils, and changes in behaviour such as restlessness, anxiety, attention-seeking or unexplained fear

• Generalized seizures (stiffness, rapid twitching)

They involve both sides of the brain. Generalized seizures can occur on their own, or they can start as a focal seizure (more on that below) and develop into a generalized seizure. In most cases, during a generalized seizure, the dog loses consciousness, and drooling, urination and defecation may also occur. Movement occurs on both sides of the body. Aspects of generalized seizures are often referred to as tonic, clonic, tonic-clonic, and myoclonic. These terms are defined below:

• Tonic: increased muscle contraction (stiffness) lasting several seconds to minutes
• Clonic: involuntary rapid and rhythmic muscle contractions (twitching)
• Tonic-clonic: a tonic phase followed by a clonic phase
• Myoclonus: sporadic jerks usually on both sides of the body

Generalized seizures can also occur without convulsions. Atonic seizures, also called drop seizures, cause a sudden loss of muscle tone and usually lead to collapse.

Focal seizure that progresses to a generalized seizure

In this case, a focal seizure is followed by a generalized seizure. This is the most common type of seizure seen in dogs. A focal seizure is often very short (several seconds to minutes), and secondary generalization follows quickly. A focal seizure can be difficult to detect because of its short duration, and it is important to tell your vet what happened before the convulsions start, to help them determine what type of seizure your dog is having.

What causes epilepsy?

A number of different underlying diseases and other factors can cause seizures that lead to epilepsy. In general, epilepsy can be classified as 'structural' (where an underlying cause can be identified in the brain) or 'idiopathic' (where no underlying cause can be identified and often a genetic predisposition is assumed or the cause is unknown).

Epilepsy can develop in dogs of all ages, depending on underlying factors.

• Idiopathic epilepsy (without known cause)
• Structural epilepsy (caused by a known problem in the brain)
• Reactive seizure (temporary brain changes)

What should I do if my dog has a seizure?

Stay calm. Most seizures are brief, and dogs are usually unaware of them. Although a seizure can look frightening, the dog is unlikely to be in pain during it. Move nearby furniture out of the way to help keep your dog safe. Never put anything in your dog's mouth, including your hands.

Your vet may prescribe 'emergency medication' to reduce the length of the epileptic episode.

Observing your dog's seizure

Most seizures last only one to two minutes, but time your dog's seizure so you know how long it lasts. It is very useful to observe the seizure carefully. Specifically, what were the first signs? Was one side of the body affected first? What movements did your pet make (did your dog paddle its legs, tremble or make chewing motions)?

These notes, together with a seizure diary, can give your veterinarian useful information.

Duration, frequency and severity of seizures

How often a dog with epilepsy experiences seizures can vary greatly between individual dogs and over the course of a dog's life. A seizure diary helps you and your veterinarian assess how well the medication is working and whether the dose is appropriate. Some dogs experience frequent seizures (e.g., more than one a day), long seizures, or those that immediately lead to new seizures – in other words, they do not return to normal between seizures. This pattern poses a particular risk to your dog's health.

The following seizure patterns can be life-threatening and require urgent attention:

• Cluster seizures (two or more seizures within 24 hours)
• Status epilepticus (seizures longer than five minutes or two seizures without the dog returning to "normal" between them)

What can trigger seizures in a dog?

Some dogs seem to have 'triggers' that lead to seizures, while others do not. Triggers can differ from dog to dog. In people with epilepsy, common triggers include: fatigue, lack of sleep, stress and stopping antiepileptic drugs (if prescribed).

Stress is the most commonly cited trigger by owners and can be caused by a variety of situations including changes in the environment, changes in routine, car rides, thunderstorms and visits to the vet - just to name a few.

Some owners report that certain foods or medicines seem to trigger seizures. A seizure diary may help identify a pattern.

How is epilepsy diagnosed in dogs?

Epilepsy in dogs is usually diagnosed by ruling out other causes.

The veterinarian begins with a detailed physical examination and medical history, including a check for lumps or masses that could indicate a tumour.

The vet must listen to both the heart and lungs to rule out other possible causes.

In addition, you will likely need blood and urine tests to identify abnormal cell counts or unusual biomarkers (e.g., proteins, hormones and electrolytes).

An MRI can reveal abnormalities in brain tissue. Cerebrospinal fluid (CSF) analysis may help identify signs of a tumour or swelling in the nervous system.

What treatment options are currently available and can epilepsy be cured?

In most cases, epilepsy in dogs cannot be cured. Maintaining a seizure-free status with no unacceptable side effects is the ultimate goal of antiepileptic drug (AED) therapy. This balance is achieved in 15-30% of dogs.

Therefore, the goal of medical treatment is to improve your dog's quality of life by reducing the frequency and severity of seizures.

Owners should be aware that although medication can significantly extend life expectancy and improve quality of life, dogs with epilepsy usually have a somewhat shorter life expectancy.

Therapy with antiepileptic drugs (AED)

If your veterinarian recommends starting AED therapy, have a thorough discussion to understand the importance of this treatment and why it is necessary. Regular follow-up visits are then needed to monitor the condition and possible side effects of medication. Once started, AED treatment is continued indefinitely, in most cases for life, with periodic health checks and blood tests to ensure correct drug dosage, treatment effectiveness and minimal side effects.

It is important to be consistent with any treatment, therefore:

• Give your pet medicine at the same time every day
• Give the correct dose of medicine
• Continue treatment and do not stop without first talking to your veterinarian

Which AED will my dog be prescribed?

Your vet will be able to advise you on which anti-epileptic drug (AED) is most suitable for treating epilepsy. Factors that can influence the veterinarian's decision are usually the type of seizures, their frequency and possible kidney or liver problems.

In the EU, the first-line medicines your veterinarian may prescribe for canine epilepsy are imepitoin or phenobarbital.

Next steps

If the desired seizure reduction is not seen with the 'first line' drugs, it is also possible to add potassium bromide.

Diet: After diagnosis, keep your dog's diet consistent, because changes in food can affect the blood levels of some medicines. Furthermore, new types of nutrition are currently being developed that could further improve seizure control.

How can I know if the medicines are working?

Treatment with antiepileptic drugs is generally considered successful if the frequency of seizures is reduced by at least half, although the ideal is for seizures to be completely absent.

An accurate seizure diary helps you and your veterinarian assess whether the medicine is working. This is the best way to see if there is improvement.

Do these medicines have side effects?

Unfortunately, yes. Side effects may appear shortly after starting treatment or when the dose is increased. They usually disappear or diminish in the following weeks as the body develops tolerance to the medication.

In some cases, side effects persist and must be monitored to ensure their severity does not compromise your dog's quality of life.

What are the common side effects of antiepileptic drugs?

Common, potential side effects of AED treatment include:

• Drowsiness
• Unsteady movement or stance
• Increased appetite and thirst
• Drooling
• Vomiting
• Diarrhea
• Hind-leg weakness
• Weight gain
• Excitability
• Restlessness
• Changes in behavior

If your dog stops having seizures or develops life-threatening side effects, the vet may recommend discontinuing treatment, but under no circumstances should you decide this on your own, as this in itself can cause seizures and status epilepticus. Consult your veterinarian before making any changes.

And finally, research has shown that CBD (cannabidiol) has a beneficial effect on people suffering from epilepsy and related diseases. Back in 2018, the US Food and Drug Administration (FDA) approved a cannabidiol-based medicine called Epidiolex for seizures associated with Lennox-Gastaut syndrome and Dravet syndrome. Its approval was later expanded to seizures associated with tuberous sclerosis complex (TSC). You can find more information about these conditions and how Epidiolex is used to treat them here.

Research into CBD and epilepsy in dogs is available here. 

VetHealth is a combination of cannabidiol (CBD) and cannabigerol (CBG), without the presence of psychotropic molecules and terpenes, which is why it is completely harmless to animals.

Clients whose pets have epilepsy have consistently shared positive experiences with us. Please get in touch if you have questions.

IMPORTANT: This text is not intended to diagnose or treat your pets. If you have noticed the symptoms mentioned in the text, contact your veterinarian, ideally a veterinary neurologist, first.