How Prone to Seizures is Your Dog (or Cat)?

Dr. Karen Becker. February 15th 2011
A seizure is an incidence of unanticipated, abnormal electrical activity in your pet’s brain.

Symptom-wise, it can range from a minor imperceptible twitch, to a full-blown grand mal seizure during which your pet loses consciousness.

Seizures can last from just a few seconds – so short, in fact, you’re not even sure it was a seizure because it looked more like a minor head bobble, tremor, spasm or a simple cramp – to several minutes.

There are two types of electrical impulses inside your dog’s or cat’s brain – excitatory and inhibitory. There is a proper ratio of excitatory to inhibitory impulses, and when excitatory impulses overtake inhibitory impulses, a seizure can be the result.

Whether your pet has a minor twitch or a grand mal event depends on what part of the brain is involved and how many excitatory impulses are generated.

The point at which excitatory impulses overtake inhibitory impulses is called the seizure threshold. In a healthy pet this seizure threshold is high, meaning the potential for a seizure is low.

There are a few things that influence your pet’s seizure threshold, including:

  • Genetics
  • Head trauma
  • Infection
  • Exposure to toxins

Three Phases of a Seizure

Every seizure has three phases: pre-ictal, ictus, and post-ictal.

The pre-ictal phase comes just before the seizure. It can last a few seconds to a few minutes.

Humans can often predict their seizures, and we suspect some pets can as well. During the pre-ictal phase, your pet may behave strangely. He may become restless or nervous. He may come to you and want to be soothed because he can sense there’s abnormal electrical activity revving up in his body.

The seizure itself is called the ictus phase.

After the seizure passes there is the post-ictal phase, which can last from a few minutes to several hours. In the post-ictal period, you may see a wide variety of responses in your pet. He may seem confused or fearful. He might stumble about as though he’s blind. He might bump into things. You might also notice nervousness, tension, or that your pet wants to be left alone or immediately go outside.

I suspect animals are very confused after a seizure because they don’t know what just happened to their bodies.

Types of Seizures

There are a few different types of seizures your pet can experience.

A petit mal seizure is the mildest and can be as insignificant as an eye movement. A grand mal seizure is the other extreme. During this serious event, a pet loses consciousness and usually falls down.

There can be paddling with the legs and vocalization during a grand mal type seizure, along with jerking and twitching. Some pets lose bowel and bladder control.

Status epilepticus is a grand mal seizure that doesn’t resolve. This is a medical emergency in which breathing ceases and the animal can die. If your pet is experiencing a grand mal seizure and isn’t coming out of it, it’s critical you get her to an emergency veterinary hospital right away in order to save her life.

Cats more typically have something called a focal motor seizure where only part of the body seizes. It can look like a twitch, tremor or a cramp. This type of seizure is more common in kitties and small dogs.

Cluster seizures are events that occur several times a day. Many cluster seizures are urgent care situations. If your pet has had more than one seizure in a day, I recommend you make an appointment with your veterinarian. This type of seizure can lead to continued seizing and/or progressively more intense seizures.

Seizure Causes

There are a number of different causes of seizures.

  • Head trauma which results in brain swelling can cause seizures.
  • Brain tumors are a very common source of seizures in older pets. It’s very unlikely your 12-year-old dog or cat will develop epilepsy. If you have a pet getting up in years who starts seizing, unfortunately, the likely cause is a brain tumor.
  • Bacterial, viral, fungal and parasitic infections can also cause seizures.
  • Certain immune-mediated diseases can cause seizures.
  • Cervical subluxation can also cause seizures, and this is something many pet owners don’t realize. I see this type of seizure a lot in dogs that are chained outside. They run out the length of their chain chasing after a bunny, and when the chain snaps back against the neck it causes a high cervical traumatic injury of either the C1 vertebrae (the atlas) or C2, the axis.The C1 is the first cervical vertebrae in animals, and it articulates with the brain stem. When there is increased cerebrospinal fluid pressure in the brain stem, it can lead to a seizure.I recommend you harness your pet not only for walks, but also if he’s ever chained out. It’s important your pet is not able to increase pressure on the neck, because high cervical subluxations and other chiropractic issues in the neck can caused an increased likelihood of seizures.
  • Congenital malformation (birth defects) of the brain stem or spinal cord is also a common cause of seizures. The Cavalier King Charles Spaniel is a breed well-known to have a birth defect in the occipital bone leading to cerebellar herniation, a condition known as Syringomyelia.
  • Liver disease can indirectly cause seizures. The liver is designed to process toxins, and if it can’t do its job effectively, poisons can build up in your pet’s bloodstream and cross the blood-brain barrier. Your pet can develop a condition called hepatic encephalopathy which can lead to toxin-based seizure activity.
  • Low blood sugar can also be a cause. Diabetic animals taking insulin can develop low blood sugar-based seizures, or animals with insulinomas (a pancreatic tumor)
  • Other metabolic conditions such as hypothyroidism can also cause seizures. Interestingly, in one study 70 percent of dogs that were clinically hypothyroid had a history of seizures. I strongly recommend all dogs that have seizures be tested for hypothyroidism.
  • Poisoning can lead to seizures. Lead poisoning, mercury poisoning, and plant poisoning (the marijuana plant, sago palm and castor bean plant, for example) can all induce seizures in your pet.Fertilizers, pesticides, insecticides and herbicides are all well-known to cause seizures.Human drugs like NSAIDs (non-steroidal anti-inflammatory drugs), antihistamines, antidepressants and diabetic medications can all cause seizures in pets.

    Veterinary drugs are also known to create seizure potential. In fact, neurotoxic topical chemicals like flea and tick preventives are included in the list of drugs that potentially cause seizures.

  • Heat stroke is also a too-frequent cause of seizures in pets.

Vaccines and Seizures

Certainly not least among the causes of seizures are vaccines.

Veterinary vaccines still contain thimerosal or organo-mercury compounds as adjuvants to boost the body’s response to the immunization.

Needless to say, heavy metals cross the blood-brain barrier, and since your pet’s central nervous system doesn’t contain the equivalent of a liver, there’s no removing those heavy metals.

Another way vaccines can cause seizures is their implication in the condition known as autoimmune encephalitis. Vaccines can spark an autoimmune reaction that causes secondary swelling in the brain, which in turn can bring on a seizure disorder in your pet.

Diets and Seizures

Nutritionally related health issues can also be the cause of seizures. This is something many people never consider.

Diet has a two-fold potential implication when it comes to seizures.

Number one is if your pet has food allergies. This can cause a systemic inflammatory response that can decrease her seizure threshold.

Number two, the pet food you feed can contain synthetic chemicals, preservatives, emulsifiers or other ingredients that can cause systemic inflammation and decrease seizure threshold.

If your pet has been on the same diet for awhile or eats highly processed food, it could be a potential cause for seizures.

One of the things human medicine recommends for some people with seizure disorders is a ketagenic diet – one that contains no carbohydrates, moderate fat and high amounts of protein. Interestingly, this type of diet is actually species-appropriate for dogs and cats.

So if ketagenic diets are being used to help control seizures in humans, it certainly makes sense to me they could do the same for your dog or cat.

When I get seizuring patients in my practice, I strongly urge clients to eliminate carbs from their pets’ diets and feed them meals with moderate fat and high protein content. This way of feeding is not only species-appropriate, it also eliminates pro-inflammatory carbohydrates, which helps control systemic inflammation which can lead to seizures.

There are also some herbs that can decrease an animal’s seizure threshold. It’s not the herb itself which causes the seizure, but if your pet already has a seizure disorder or a low threshold, there are certain herbs and essential oils than can trigger seizures.

The herbs kava-kava, skullcap, evening primrose oil, borage seed oil, goldenseal, ginkgo, ginseng and wormwood have all been implicated. Essential oils such as eucalyptus, fennel, hyssop, pennyroyal, rosemary, sage, and tansy have also been implicated in decreasing seizure threshold.

What to Do If Your Pet Has a Seizure

If your pet has a seizure, it’s important to speak with your veterinarian about it. (Obviously, if the seizure is a grand mal and your pet isn’t coming out of it, you need to seek emergency veterinary care immediately.)

If your vet rules out all potential causes of your pet’s seizure, then you’re left with a diagnosis of idiopathic epilepsy, which means seizure of unknown origin.

In most cases of this diagnosis, vets will want to start your pet on an anti-seizure medication. However, at my practice, the rule of thumb is this: an animal must have in excess of one grand mal seizure a month in order to even consider drug therapy.

There are a whole host of natural substances than can help increase your dog’s or cat’s seizure threshold and decrease the potential for these events. In my practice, we use acupuncture, herbal, chiropractic and nutraceutical therapies to extend seizure thresholds.

We often use these modalities as the sole treatment for mild cases. For animals with frequent grand mal seizures, we often create an integrative protocol of natural therapies and drug therapy.

If you have a pet that has had a seizure, it’s important to track the dates, times and intensity of the events. I often see correlations between seizures and a particular time of month, year or even phase of the moon. Strange, but true!

If you’re able to identify a seizure cycle in your pet, your vet can help you devise a plan to control these events, which should of course start with use of the most safe, natural treatment options available.