What is Epilepsy in dogs
Epilepsy is a brain disorder characterised by recurrent seizures without a known cause or abnormal brain lesion (brain injury or disease). In other words, the brain appears to be normal but functions abnormally. A seizure is a sudden surge in the electrical activity of the brain causing signs such as twitching, shaking, tremors, convulsions, and/or spasms.
The exact cause of epilepsy is unknown, but a genetic basis is suspected in many breeds. Common breeds that have a higher rate of epilepsy include: Beagles, Golden Retrievers, Border Collies, Border Terrier, Poodle, Boxer, Dalmatian and Vizsla.
Additionally, seizures in dogs can be cause by several other conditions, including head trauma, heatstroke, low blood sugar, brain bleed, brain tumour, and toxins.
Written by Dr. Mariella Roberts, Veterinary Surgeon, Animal Trust Vets CIC | Published March 2025 | Review date March 2027 | This advice is for UK pets only and is not a replacement for seeing a vet
Dog seizure symptoms
Seizures can vary in appearance and can be localised/focal (only affecting part of the body) or generalised (affecting the whole body).
Generalised seizures are more common and are often characterised by:
stiffening of the neck and legs
stumbling and falling
uncontrollable chewing
Drooling
paddling of the limbs
loss of bladder control
passing stools
vocalising
violent shaking and trembling
Seizures can last a few seconds to a few minutes, on average about 30-90 seconds, and the pet is typically unaware of the surroundings during this period. In some rare cases, the seizures will not stop or are prolonged and this is referred to as status epilepticus.
Prior to the seizure, many pets will also experience the ‘aura’ stage; this is characterised by the pet appearing anxious, frightened, or dazed, as if the pet can sense an upcoming seizure. After a seizure, the pet may appear confused, disoriented, dazed, or sleepy; this is called the postictal period.
When to contact your vet
When your dog is having a seizure, it’s important to remain calm and remember that your pet is not in pain, as he or she will not be fully conscious. Ensure that your dog is not in a position which could put them in danger and try to make sure the area is clear around them. It’s important not to move them, if possible. Never put your hand inside their mouth – dogs cannot swallow their tongues during fits, and you may put yourself at risk of your pet unintentionally biting you. Contact your vet right away if your pet has more than one seizure in 24 hours, or a seizure is prolonged for more than 5 minutes.
Diagnosis
Epilepsy is a diagnosis of exclusion; the diagnosis of epilepsy is made only after other causes of seizures have been ruled out. A medical examination is important and might be followed by diagnostic testing such as blood and urine tests. Additional tests such as a CT scan or an MRI may be recommended, depending on the initial test results. In many cases a definitive cause is not found; these cases are usually labelled as idiopathic epilepsy.
Canine epilepsy treatment
Anticonvulsants (anti-seizure medications) are the treatment of choice for epilepsy. There are several commonly used anticonvulsants, and once treatment is started, it will likely be continued for life. Stopping these medications suddenly can cause seizures, so it is important to continue on treatment, as advised by your vet.
Irregular dosing schedules (including starting and then stopping the medication or forgetting to give pills causing blood levels to fluctuate) may predispose your pet to more frequent or more violent seizures, so it is important to give the medication on a regular schedule.
The more commonly used medication is phenobarbital, and it has been used for many years with good success. Other medications include Potassium Bromide (KBr), Zonisamide, Levetiracetam and Gabapentin. In some patients, multiple drugs may need to be used at the same time.
Blood monitoring tests are done at specified intervals (weeks to months) for Phenobarbital and Potassium Bromide. These tests are used to help determine the correct dosing levels but also to check organ function, as, in some cases the medications may occasionally have unwanted side effects (although this is rare).
Prevention
Most dogs do well on anti-seizure medication and are able to resume a relatively normal life. Some patients continue to experience periodic break-through seizures, but in most cases the frequency is significantly reduced. Some dogs require occasional medication adjustments, or the addition of other medications over time.
Outlook
Outlook is usually very good if owners give medications as advised, pets are regularly reviewed by their vet and monitoring tests are carried out as necessary.
There are some cases that can be more difficult to manage, and not all patients will respond effectively to standard treatment. Fortunately, these cases are relatively uncommon.
It is important to remember that idiopathic epilepsy is a lifelong condition and will require ongoing medical management in most cases. In addition, although idiopathic epilepsy is one of the most common causes of seizures, there are other potential causes, and this will have an impact on the outlook of the patient.