Seizures: When the Brain Misfires

Seizures are frightening things to experience

Published: July 21, 2016

Peanut Teri Oursler
Photo by Teri Ann Oursler, DVM
It was not the way to start a morning, brushing my teeth and hearing the scrambling of dog feet on the tile floor with my youngest son hollering “Mooooom” in a panicked voice. I went running out to the kitchen to see my 11-year-old dog, Peanut, having a generalized (grand mal) seizure, while my husband and son tried to keep her from falling down the steps and getting hurt.

Seizures occur fairly commonly in dogs, as they do in people, and are frightening things to experience even for those of us who deal with them as part of our professional lives. Seizures can appear in different ways but the type of seizure that is the scariest to observe is a generalized seizure that affects the whole body. During a generalized seizure the patient falls to the ground and the limbs thrash; the patient may urinate and or defecate, and drooling is common. That is what my Peanut girl was doing while we tried to keep her from falling down the steps. My mind whirled, thinking of all the reasons she could be having a seizure.

Kneeling down to calm Peanut and my family, I uttered words that deep down I knew were probably not going to turn out to be true: “She will be OK. We can start her on drugs to stop the seizures. It's probably just idiopathic epilepsy.”

Idiopathic epilepsy is a seizure that occurs in an otherwise normal brain. The good news is that if the seizures can be controlled, the dog may have an otherwise normal lifespan.

Seizures in dogs and cats can be caused by idiopathic epilepsy but they also may be due to more serious conditions including: congenital abnormalities, toxins, infectious diseases, immune-mediated diseases, metabolic diseases, brain tumors, traumatic injuries, and vascular accidents (strokes).

So why did I think, deep down, that I was wrong in saying that idiopathic epilepsy was the cause of her seizure? Let me count the ways…

Age plays a role in determining how likely a certain cause is for any given patient. For instance, seizures in puppies and kittens are much more likely to be due to congenital diseases than in a 10-year-old dog or cat, and seizures due to idiopathic epilepsy usually begin between the ages of 6 months to 5 years.

In addition to age, certain dog breeds have a higher frequency of some diseases that cause seizures than other breeds. For instance, any small breed dog can be prone to episodes of hypoglycemia (low blood sugar), especially if it is a puppy. Yorkshire Terriers are prone to congenital liver anomalies (portosystemic shunts), hydrocephalus and immune-mediated diseases of the brain. Golden Retrievers and Boxers are both predisposed to cancer of all kinds, including brain tumors. Golden Retrievers, German Shepherds, Border Collies and quite a few other breeds have a high incidence of idiopathic epilepsy.

Lifestyle differences can also help determine the cause of the seizure. Is the dog vaccinated for rabies and distemper? Is he confined to a yard, or does he run, thereby increasing the chances of toxin ingestions and trauma?

While Peanut was a Labrador/Border Collie cross, both breeds predisposed to idiopathic epilepsy, she was not even close to the right age for that to cause her first seizure. She was not a dog who was allowed to run, so trauma and toxins were ruled out right away. She was current on her vaccines, including rabies. I bundled her up and took her to my clinic where bloodwork revealed that she had no metabolic reasons for her seizure. I was whittling away at the list, wiping one category off at a time and coming up against the least treatable causes of seizures.

The last categories on the list consisted of immune-mediated disease, a bacterial or viral infection, as well as cancer. Diagnosing these last three categories requires some advanced testing, such as a CSF tap (collecting cerebrospinal fluid), MRI or CT scans ― none of which I had the ability to do in my clinic. In addition, for the average pet owner, these tests can be cost prohibitive and may not reveal any treatable diseases, especially in an older pet.

Due to the severity of her seizure, I started my girl on anti-convulsant drugs immediately, but over the next two days she progressively got worse with increasing signs that her problem was located in the brain, due either to a tumor, a stroke, or immune-mediated disease. We could not determine which as she was never stable enough to transport and anesthetize for further diagnostics. I ended up euthanizing her, with my husband and son talking to her, petting her, thanking her for 11 years of love and fun.

What should you do if your dog just had his first seizure?

  1. Keep you and your dog safe. Just as in people, dogs and cats have no control over their body movements when seizing, so it is important not to put your hands or face near the animal’s mouth during a seizure. If the patient is on a bed or somewhere they might fall, it is a good idea to carefully move them to the floor.

  2. For a first seizure, it’s important to take your pet to the veterinarian for diagnostics. The list of causes is long and the best hope for treatment in most all of those diseases is early intervention. The hope is that the seizure will be a one-time occurrence, even though the cause may not be identified, or that the patient will have idiopathic epilepsy. The good news is that about 70% of veterinary patients with idiopathic epilepsy are well controlled on anticonvulsant medication.

  3. Despite the dramatic appearance of a generalized seizure, if the seizure is brief (less than 5 minutes by your watch), and the patient makes a good recovery within the next 24 hours, most seizures are not immediately life threatening. Seeking immediate veterinary attention is always a good idea but it is essential if the seizure lasts longer than 5 minutes. Irreversible brain damage secondary to the seizure occurs after 20 minutes and it can take that long to bundle up and transport your dog to the veterinarian. As an aside, the 5-minute time limit applies only to the seizure itself, not any abnormal behavior that may follow the seizure, such as blindness, pacing, aggression, or drinking a lot.

  4. If your dog has recurrent seizures, you can use the 5-minute time limit as a guide as to when the seizure has become an emergency that requires a trip to the veterinarian, rather than a notation in your seizure log book.

Regardless of cause, if recurrent seizures are documented, anticonvulsant medication is usually indicated to try and control the seizures. Unfortunately anticonvulsant medication is a symptomatic treatment, not a cure. The aim is to have as few seizures as possible with minimum side effects. Fortunately, a number of anticonvulsants are available from which to choose.

Living with a seizing pet is a difficult matter. It's necessary to give the anticonvulsant medication regularly and monitoring is needed when certain drugs are used. In some cases, adverse side effects can be more of a problem than the seizure itself, requiring a change in medication.

In order to maximize the chance of successful seizure control, close communication between owner and veterinarian is necessary. It is helpful for the owner to keep a seizure log and there are several excellent on-line resources to help owners do this. Patience is also necessary because time for the drug to work on the brain varies from drug to drug, and dog to dog. Assessing effectiveness takes time, dosage changes, and sometimes drug changes.

As with all of my cases, I try to learn something from each and every animal I treat. As I look back on my time with Peanut, I missed some signs that she had brain changes; she had become increasingly fearful of things she had never let bother her before. I attributed these behavioral changes to age. In retrospect, I am sure it was the start of her disease. Would recognizing that sooner have changed anything? There is no way to know since my crystal ball is in the shop and my retrospectroscope is cloudy.

Bye, Peanut, I love you and miss you.


Louise Clifford
May 12, 2020

Great article. Our German Pointer started seizures last week. He's undergoing blood tests. Seizures are less than 5mins but it's come out of the blue. I'm very anxious and won't let him out of my sight

October 15, 2016

Thank you so much for your story because we just recently went through this too.  Our baby was Sandy a 10.5 year old golden lab and golden retriever mix.  She was an amazing friend to us and we ultimately had to euthanize her due to the seizures. It started with one and then when we didn't have anymore until about 4 weeks later and they wouldn't stop we had to make the choice we never wanted to.  Her blood was also fine and everything pointed to neurological issues.  Before we could even try to get her a neurological exam she had 4 seizures in 3 days.  She was becoming less and less our dog because whatever was causing them was destroying her. It was so painful to lose our beautiful girl and we were able to surround her with love and have her euthanized at our home which was the best for her and our family.   Thank you for sharing your story because even though you know it's the right thing to do you still feel awful about it.

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