Understanding Canine Epilepsy

What is a seizure?

A seizure occurs when there is a misfiring of neurons in the brain, causing an “electrical storm” of brain activity. In response to this brain activity, the dog’s muscles react accordingly resulting in the physical manifestation that we recognize as a seizure.

What are some causes of seizures in dogs?

Seizures can be caused by a number of things, including, but not limited to:
- head trauma
- congenital defects such as hydrocephalus
- infectious diseases such as distemper or cryptococcosis
- hypoglycemia
- hypothyroidism
- ingestion of poisonous substances
- reaction to vaccinations or certain medications
- reaction to flea/tick preventatives
- organ disease
- bacterial infection
- brain tumor

These acquired causes may result in singular or multiple seizures. If seizures happen recurrently then the disorder is called “epilepsy”. If the cause of the seizures is unknown, then it is termed “idiopathic epilepsy”, which basically means that the dog is having seizures but we don’t know why.

What is a seizure trigger?
A seizure trigger is some stimulus that can result in a seizure in certain dogs. What is a trigger for one dog may not be a trigger for another dog. When a trigger exposure level surpasses an individual dog’s seizure threshhold, then a seizure results.

What are some common seizure triggers for dogs?

Some seizure triggers are more common than others. They include, but are not limited to:
- vaccinations, particularly Rabies vaccinations
- flea/tick preventatives, particularly Ivermectin (Ivermec)
- nutritional factors including protein levels, grains, chemical preservatives, artificial colors or flavors
- turkey meat
- herbs, plants or fragrances of rosemary or lavendar
- stress such as thunderstorms, fireworks, excitement, visitors, etc.
- changes in weather, air pressure, humidity
- loud noises or flashing lights
- over-exertion
- chemicals such as household or industrial cleaners, detergents, pesticides, herbicides, fungicides, fertilizers
- scented products such as air fragrences, perfumes, deoderizers, detergents/cleaners

How do I know if my dog is having a seizure?

Seizures can manifest themselves in a variety of different ways. They are normally divided into two catagories: general and partial. General seizures result from “electrical storm” occurs everywhere. Partial seizures result when the “electric storm” is limited to one area.

Further, there are a variety of different types of seizures:

Grand Mal (General tonic clonic) – These seizures involve the entire body of the dog. They will go rigid, collapse, and then begin flailing their legs in a characteristic “running” motion. Often also accompanying grand mal seizures is jaw chomping, excessive drooling, uncontrolled urination or defecation, labored breathing, failure to respond/rouse, vocalizations.

Petit Mal (Partial or Focal) – These seizures manifest themselves in one area of the body only. Simple focal seizures affect the area of the brain involved in movement. As such, the dog is often conscious and aware of their surroundings, while presenting twitching in one area of their body, commonly the face. A complex focal seizure affects the area of the brain involved in behavior. This will often result in the dog losing awareness of their surroundings while exhibiting abnormal behavior. Common behaviors are “fly snapping” or senseless running with seemingly little to no control. Complex focal seizures are also sometimes referred to as psychomotor seizures.

My dog had a seizure, should I take him to the vet?

Eventually, yes. But there is generally no need to rush to the vet immediately. If possible, allow the dog to recover from the seizure before adding the extra stress of a car ride and a vet visit.

Situations when you should rush to the vet IMMEDIATELY are:
- if the seizure lasts longer than 5 minutes (status epilepticus)
- if there are multiple seizures within 24 hours (clusters)

If the seizure lasts less than 5 minutes, the dog does not appear injured or in immediate danger, and is recovering safely on their own, then there is nothing that the vet will do at that moment. You would be better off to call your vet and let them know that your dog has had a seizure and follow their directions from there. Generally, allowing the dog to recover on their own and then scheduling a vet appointment for your soonest convenience is sufficient.

What do I do if my dog has a seizure?

First of all, stay calm! Gently move the dog to an area that is safe. If they have collapsed, move them away from stairs, corners, furniture or other hard objects that they could injure themselves on. If they are on furniture, ensure that they cannot fall off.

Keep your fingers away from the dog’s mouth. In humans, there is a risk of the human swallowing their tongue when they have a seizure. This is not a risk for dogs. But there is a risk of your dog unintentionally biting you if you get your fingers in the way. The last thing you need is to have to run to the hospital for stitches and a tetanus shot when your dog is having a seizure.

Lower any bright lights and turn down the volume of any televisions or radios in the area. Limit extra stimulus that may cause undue stress to the dog as they are seizing.

Speak gently and softly to the dog, do not try to stop them from seizing or “wake them out of it”.

After the seizure ends, allow the dog to recover at their own pace. Many dogs will be disoriented, confused, or uncoordinated when the seizure ends. Some dogs may be temporarily blind, not recognize you or other family members, know their own name or common commands. Pacing and aggitation is a common symptom after a seizure. Ensure that the dog does not stumble into corners or down stairs or get stuck behind furniture or in tight corners. Allow the dog to pace if they so desire. Once they are SAFELY able, offer the dog some fresh water to drink or a SMALL bite to eat (a single dog cookie, a couple of kibbles, etc.). Blood sugar levels can drop significantly during a seizure, and failing to raise them can result in more seizures. But be careful, raising the blood sugar too quickly can also result in more seizures. So be sure to only offer a small amount of bland food or treats.

The post-seizure (post-ictal) stage can last from a couple of minutes to a couple of hours. During that time, ensure that the dog remains calm, comfortable and safe.

It is important to keep a seizure diary for every seizure that your dog has. This will help you to recognize patterns and hopefully narrow down a trigger for your dog that may help in prevention of more seizures. In the diary, note the date and time of the seizure, how long it lasted, what the dog did during the seizure, any abnormal behaviour you noticed prior to the seizure, the weather of that day, what your dog ate that day and the day prior, what they did that day and the day prior, any changes in environment, any new cleaning products/chemical agents in or around the house, any activity in the neighborhood or places that you have visited with your dog recently, any recent vaccinations, medications or flea/tick treatments, and any other information that you can think of, even if it sounds silly at the time.

When I visit my vet after my dog has a seizure, what tests should I ask for?

The general course of action is to order a CBC and a Chemistry Panel. This will screen for infection/immune deficiency and organ health and function.

Something that is often not suggested by veterinarians, but is very important to screen, is a 6-panel thyroid test. There has been significant research into the correlation of hypothyroidism and seizures in dogs. Interpretting the results should take into consideration the dog’s age, breed, size, and physical activity level. In many cases, a thyroid test may come back “within normal range”, but still be lower than what is recommended when taking into consideration individual variances.

If all of those tests come back clear, then you may want to consider abdominal ultrasound and/or x-rays. A final step would include MRI, though this is an expensive option so is often not taken.

When should I consider medication for seizures?

Medication generally becomes an option if there are multiple seizures within the course of a month. If they are occurring less frequently than that, the risks of medication outweigh the risks of the seizures.

What are the primary medication options available for my dog?

There are two primary medications for treating epilepsy: Phenobarbital (Phenobarb) and Potassium Bromide (KBr)

Phenobarb is effective in 60-80% of idiopathic epilepsy and takes 1 to 2 weeks to take effect. Common side effects of Phenobarb include ataxia, excessive thirst, excessive hunger, incontinence, lethargy and exciteability. These symptoms will normally disappear after a couple of weeks. If they persist, contact your veterinarian. Phenobarb is processed through the liver, so close monitoring is essential (see below).

KBr does not have the same liver effects as Phenobarb, though it can be significantly more troublesome to the digestive system so should be given with food. KBr takes up to 3 to 4 months to reach full effect so should not be used if immediate control is required. To get around this time delay, a higher loading dose is often prescribed for the first week. When on KBr, chloride intake food levels must be monitored closely, and any switches in food brand or formula must be taken very gradually so as to not disrupt the levels of KBr in the blood. Common side effects include excessive hunger, excessive thirst, incontinence, exciteability, lethargy, ataxia, nausea, diarrhea, or bromide toxicity. These symptoms should disappear within a couple of weeks. If they do not, contact your veterinarian.

Some dogs require a combination of Phenobarb and KBr to obtain the best control.

Other seizure medication options include Keppra, Felbamate, Primidone, Gabapentin and Zonisamide.

What precautions should I take after medication is prescribed?

Routine monitoring is essential, regardless of which medication is prescribed.

If your dog is on Phenobarbital:
- a blood test to determine the level of Phenobarb in the blood is required 2 weeks after starting treatment
- a blood test to determine the level of Phenobarb in the blood is recommended every 6 months afterwards
- a chem panel to monitor GGT, ALT, and alkaline phosphatase (indicating liver function) is strongly recommended every 3-4 months

If your dog is on Potassium Bromide:
- if your dog was given a loading dose, then a blood test to determine the level of KBr in the blood is recommended after 1 week of treatment
- if your dog was not given a loading dose, a blood test to determine the level of KBr in the blood is recommended after 4-6 weeks of treatment
- subsequent blood tests to determine the level of KBr in the blood is recommended every 6 months afterwards
- a chem panel is recommended every 4-6 months to monitor organ health

What can I do at home to prevent more seizures?

There are a number of steps you can take at home to prevent additional seizures or to lessen the severity of impending seizures.

Nutrition plays an important role in our dogs lives. A home prepared diet, either cooked or raw, is recommended so as to avoid unnecessary fillers or grains, chemical perservatives, flavors, colors, or synthetic nutrients. Preparing meals for your dog takes significant research and effort, so should not be taken lightly. Though it certainly isn’t rocket science, so with adequate reading and commitment, it is possible to provide a natural, safe, and balanced home prepared diet for your dog. If you are unwilling or unable to prepare a diet for your dog, then a high quality kibble is essential. For information on how to choose a good quality kibble, consult the Dog Food Analysis website and the Dog Food Project website. In general, if you can purchase the food at your favorite grocery store or at your vet’s office, it is NOT a good quality food and is potentially doing more harm than good.

Changing how you clean and treat your home, yard, and garden can make a significant difference in the severity of seizures that your dog may have. Take into consideration the amounts of chemicals that you use around the house. Attempt to replace those chemicals with natural alternatives and limit the use of chemicals to only those that are absolutely necessary.

Consider a minimal vaccination protocol with your dog. Titer testing is an available alternative to vaccinations, so discuss that option with your veterinarian. Also source out natural alternatives to pest prevention. There are a variety of dog-safe natural insect repellents on the market, so check out your options.
Most importantly, do some independent research and reading. Veterinarians are not guaranteed to know everything about epilepsy. You know your dog best, and you are the best person to take the initiative to make a difference in your dog’s life. Don’t rely on everything that your vet recommends without asking questions, making suggestions, or requesting explanations. Take a pro-active stance in dealing with your dog’s epilepsy, stand your ground for what you feel is right.