The 5 Dog Seizure Causes + Symptoms (you NEED to know about)

Watching your dog have a seizure must rate as one of the most upsetting things that can happen to any dog owner.  Dog seizure causes are numerous so what causes seizures in dogs?  Here I run through the top 5 groups of conditions causing dog seizures and the different symptoms you might notice with each one.



Toxicity or poisoning is one of the most common causes of seizures in dogs.  Some foods like xylitol or poisons like metaldehyde slug and snail bait are common things in the house or garden that can cause seizures in dogs, especially in young dogs.

Some of these poisons can cause seizures to start within 30 minutes and for seizures to be the only cause.  Other poisons causing seizures might result in a number of other symptoms (like vomiting and diarrhea) before causing seizures some time later.  There are many other signs your dog might have been poisoned.

If there is any chance your dog has eaten something poisonous then you should contact your veterinarian straight away for advice.

Learn about the most common pet poisons here

Dog epilepsy

Along with poisoning, this is one of the most common causes of seizures in dogs.  Dog epilepsy typically starts at some time between 6 months and 6 years of age so is a disease of young dogs.

Epilepsy is a diagnosis of exclusion.  There is no one test that can diagnose epilepsy in dogs.  Instead we rule out the other causes of seizures in dogs and if there is no other explanation (and no reason to discount epilepsy like old age) then epilepsy is diagnosed.

Epilepsy in dogs can not be cured but it can be managed very well in the majority of cases, reducing seizure frequency.

An older dog who starts to have seizures is not going to be caused by epilepsy.  If your dog is showing other symptoms of being unwell then epilepsy is also an unlikely cause.  Most epileptic dogs will appear perfectly healthy apart from when they are having a seizure.


Organ disease + hormone abnormalities

Diseases such as kidney disease, liver disease, liver shunts in young dogs as well as hormone problems such as diabetes or insulin producing tumors can all cause seizures.  They do this by causing an imbalance in salts or sugars within the blood or through the build up of certain toxins that then cause seizures and fitting.

If a dog is having seizures because of another disease then they will also have other symptoms.  These might be drinking or urinating a lot, losing weight or many other symptoms.  It really depends on what disease they are suffering from.


Various different types of infection including parasites (such as Neospora), tick borne disease (like Lyme Disease) and general bacterial sepsis can all cause seizures in dogs.  In some cases seizures may be the only symptom of infection.  In most cases though, your pet will also be feeling unwell, have a temperature or showing other symptoms of infection.

Brain lesions

Tumors are a common cause of seizures in older dogs (along with organ or hormone disease), hydrocephalus is something that affects younger dogs (typically those breeds with domed heads).

Again, dogs with these conditions will typically have other symptoms.  They will generally show other signs of nerve disease when they are not having seizures.  This might be having their head tilted to one side or stumbling or wobbly when walking.

Diagnosing the cause of seizures

In the majority of cases of dog seizures, with the notible exception of epilepsy, there are likely to be other signs and symptoms your dog is showing which may give your vet an idea of what is going on.

Diagnosis of the cause of seizures can sometimes be tricky.  Your vet may want to take blood + urine tests, ultrasound or xrays, along with brain imaging and sampling of the fluid around the brain.

If you have any questions then please leave me a comment below.

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