Diagnosis and Treatment of Epilepsy In Dogs

Updated November 28, 2020

Idiopathic epilepsy is the leading cause of seizures in dogs. If you’re already sure that’s what’s wrong with your dog, this page is for you.

Click here for the different types of seizures and causes of seizures in dogs

What Is Idiopathic Epilepsy?

In theory, idiopathic epilepsy is a specific brain disease. In practice, it is a seizure disorder for which no cause can be established.

We don’t find the cause for most dogs who have seizures. Epilepsy is the catch-all term for these. Sometimes you can identify and avoid a trigger, but most of the time seizures seem to come out of nowhere.

Diagnosis of idiopathic epilepsy is by exclusion:

  1. No history of access to poisons
  2. A description of a typical epileptiform seizure (if you can take a video it’s very helpful to distinguish from collapse due to heart failure)
  3. Onset of signs under 6 years of age
  4. A normal physical examination and blood tests
  5. Minimal progression or worsening over time

It is perfectly OK to go directly to treatment if you’ve ticked all these boxes. Dogs with prolonged seizures or clusters, worsening over time, onset over 6 years of age or any findings on exams or tests need further testing or referral.

Please also note that many of the causes of tremors and shaking are easily confused with seizures. Examples are ‘white shaker syndrome’ in small & toy breeds and ‘canine epileptoid cramping syndrome’ in Border Terriers. Click the link to read more.

Treatment of Idiopathic Epilepsy

First, is treatment really necessary? Assuming your vet agrees, there is rarely any need to treat partial seizures other than identifying and avoiding the triggers.

There is also no need to treat very occasional generalised seizures if they cause no lasting effects, are short in duration and you are able to cope personally.

Cluster seizures and status epilepticus must always be treated urgently. The only way to stop prolonged seizures is for a vet to give emergency drugs.

Treatment involves a number of medications, usually added in the following order:


Despite its poor reputation in humans, ‘phenobarb’ remains the most effective seizure medication in dogs. It is usually extremely well tolerated and very cost effective. When first used, it causes sedation that wears off after a week and from then on should have no ill effects.

Dogs on phenobarbitone need periodic blood tests for liver enzymes as well as levels of the actual drug. Often the dose needs to be increased from its starting level for best results.


Potassium bromide is rarely very effective on its own but adds significantly to seizure control when used together with phenobarbitone. Once again, it’s usually very safe but monitoring is required. It should be given with food.

Bromide is slow to take full effect, with blood levels increasing right up to four months from the start of therapy. That said, we expect better control within a few weeks of starting.


Pexion® is a new drug registered in Australia as an aid in the treatment of idiopathic epilepsy in dogs. Our personal experience is that it is less effective than the drugs listed above but is useful for cases where control is difficult.

Levetiracetam (Keppra®)

Of the unlicensed human medications, we have some success with levetiracetam for cases that respond poorly to standard therapy or when side effects are excessive. The drug is very fast acting and appears mostly well-tolerated. Now that there’s a generic form, it’s also not as expensive as it used to be.

Most other drugs made for human epilepsy are very disappointing in dogs, but can be tried in an ‘off-label’ way for difficult cases. We usually recommend consulting a specialist before using these.

That is the final message: treatment of seizures is not perfect. We often get excellent results, but seizures in some dogs can remain frustratingly hard to control. However, even if we can’t stop them completely, nearly every dog should get some benefit from treatment.

Have something to add? Comments (if open) will appear within 24 hours.
By Andrew Spanner BVSc(Hons) MVetStud, a vet in Adelaide, Australia. Meet his team here. The information provided here is not intended to be used as a substitute for going to the vet. If your pet is unwell, please seek veterinary attention.

9 Replies to “Diagnosis and Treatment of Epilepsy In Dogs”

  1. I wish I read this info page when my dog first had a seizure! I really appreciate your calm, matter of fact approach. It is all very overwhelming when a dog starts having seizures, and I really do agree that perhaps medicating early isn’t necessary. It’s possible there won’t be many seizures at all.

  2. Hello. My 5 year old Siberian Husky has idiopathic epilepsy. He is on a few medications but as of lately they seem to not be working as much. He has been having what seem like focal seizures and the emergency meds don’t seem to help like they do with the grand Mal seizures. My fear is that these will continue to progress into clusters with more frequency. Is there anything else that can be done?

    1. Hi Chris. It’s always difficult and involves a fair bit of trial and error to get these cases right, so be persistent and liaise with your vet frequently.

  3. Hi my Mollie Shih Tzu is nearly 12 she has been having seizures since she was four averaging 8 approximately a year they last for about up to 9 minutes I always treat her myself she is on no meds but has CBD oh and she always vomits after seizure and you cant Ever tell when she is going to have one we can be walking and she just goes down
    It kills me but just amazing when it’s over she is fine

  4. Hi my Siberian Husky has had about 10 seizures since Friday. She has had seizures previously for a while it was about 4-6 weeks apart then she was put on Pexion for a bit and from July 2019 to Friday 3 Jan 2020. We had stopped the Pexion after a month as we were told to trial the medication. Shes had 1 or 2 and from Friday 3 Jan 20 until early this morning she has had aboout 10. We started the medication again on Sat 4 Jan 20 and she is still not herself, she is dazed and walks into things and constantly pacing her self up and down and around and gets scared when we go to pat her. I need to know if this can be looked further into and if she will return to her usual self or if she will stay like this permanently.

    1. Hi Kristina. When dogs have many seizures close together (we call this a cluster) it can sometimes cause permanent damage. I sincerely hope that’s not the case with your dog. However, to be both positive and realistic, she should return to normal if she stays on the medication and has no further seizures. Of course, seizures can be looked into further but it’s sometimes very hard to get a definitive answer on why they are happening. However, specialist care can be useful to optimise treatment if for no other reason. Good luck.

  5. Hi my 8 month old Border Terrier was recently diagnosed with idiopathic epilepsy. He started having vomiting and lack of appetite and we thought he had GI issues. The next day, he had one seizure. It was a partial seizure where his jaw/face was twitching and he had a bit of drool. The first one lasted about 20 seconds. He then had 5 more the next day (about 4-5 hours apart). They all presented about the same way (facial twitching, drool, 20-30 seconds). He acts completely normal before and after them. We brought him to the ER, they ran the tests (blood, neurological exam, liver shunt, etc.). They couldn’t find a cause so determined it was idiopathic epilepsy. We have had him on 125mg of Keppra for the past 6 days. He had one mild seizure today (milder than the others) so I am a bit concerned the clusters are starting again and/or he will face more intense seizures, but we will wait and see. I couldn’t find much info on how dangerous cluster seizures are when they present like this (partial, etc.). We are deciding whether to do the MRI or not. I never thought I would bring home a new puppy (to replace our two other senior dogs who recently passed) and have to deal with this. Life can be amazing!

      1. We looked into this but he doesn’t present with the symptoms. He had two more partial seizures even while on Keppra since I last wrote so we are back at ER.

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