Epilepsy in Dogs and Cats

Written on March 21, 2018 by Mark Troxel, DVM, DACVIM (Neurology) Hospital: Massachusetts Veterinary Referral Hospital

It can be very scary to watch a pet having a seizure. Many pet owners worry that their pet might be in pain or are suffering during a seizure. However, neither is the case, and we frequently suffer more than they do, as long as the seizures are short and infrequent. This article provides basic information about seizures and epilepsy in dogs and cats. Please see your primary care veterinarian or a veterinary neurologist for additional information.

Epilepsy is the most common neurologic disorder of dogs and cats and is defined as any condition that causes recurring seizures. Epilepsy is not one single disease. Any patient with recurring seizures has a form of epilepsy. When most people think of “epilepsy,” they are usually thinking of Idiopathic Epilepsy (“primary epilepsy”), a condition that likely has a genetic/hereditary cause and is common in humans, dogs, and cats. No test proves the patient has Idiopathic Epilepsy; it is a diagnosis of exclusion, meaning we presume the patient has this condition after ruling out other possible causes. No medication or treatment cures Idiopathic Epilepsy, but many patients can be successfully managed long-term with anticonvulsants. Symptomatic (secondary) epilepsy is due to an underlying identifiable disorder, such as a brain tumor, inflammation or infection in the brain, or low blood sugar from an insulin-secreting tumor. There are many treatment options for these patients as well.


  KEY POINTS TO REMEMBER:

  • The best source of information is a veterinarian. Don’t implicitly trust ”Dr. Google.” Be skeptical of any exaggerated claims of treatment success that you read about online.
  • Seizures are usually not life-threatening — they usually stop on their own.
  • Take your pet to a veterinarian IMMEDIATELY if any active seizure lasts longer than 5 minutes or if there are 3 or more seizures in a 24-hour period.
  • NEVER stop or change the dose of medications without speaking to a veterinarian first! This can potentially cause rebound seizures that are worse than the original seizures.
  • Most importantly, ENJOY YOUR LIFE! It’s for your pet to have a good quality of life, but it’s equally important that you do as well! The most predictable thing about seizures is that they’re unpredictable, so we can’t tell you when or how often your pet will have seizures. Fortunately, it’s quite uncommon for a pet to die during a seizure or directly because of short, infrequent seizures.

What Are Seizures?

EEG

Electroencephalogram (EEG) obtained from a patient having a generalized seizure. [click to enlarge]

A seizure is a transient, self-limiting physical manifestation of chaotic electrical activity in the brain. Our brain cells communicate with each other via excitatory and inhibitory electrical and chemical signals. When one area of the brain starts to become too excited, surrounding areas try to quiet the overexcited region. With a seizure, however, the overactive area of the brain either overrides this negative feedback or the negative feedback doesn’t occur. Each region of the brain controls a different area of the body, so the outward appearance of a seizure depends on the region of the brain that is overly active.

What Do Seizures Look Like?

Seizures can look anything…it depends on what area of the brain is overactive. If the electrical activity stays in one region of the brain, only a portion of the body will be affected, such as focal facial seizures. Many people know of or have seen a classic “grand mal” type of seizure. This is a type of generalized seizure where the excessive electrical activity occurs on both sides of the brain, so both sides of the body are affected. With this type of seizure, the patient loses consciousness, falls over to size and has stiff or paddling limbs. Some patients will have the mouth wide open or make jaw chomping motions. Drooling, urination, defecation may occur. The patient may stop breathing temporarily or have bluish discoloration of the gums, but this usually doesn’t cause any serious problems. Patients may make noise or vocalize during a seizure, but this is not due to pain. Sometimes, the seizure will start as a focal seizure involving only one portion of the body but then generalize to involve the entire body.

Phases Of Seizures

There are commonly three phases of a seizure:

  • Aura: The aura is the beginning of abnormal electrical activity in the brain, lasting only seconds to minutes. Animals may hide, seek out their owner, vocalize, or appear agitated. You might not recognize the aura as a separate phase because the duration can be very short.
  • Ictus:  This is the actual seizure when there is chaotic electrical activity in the brain.
  • Post-ictal:  This is the phase after the abnormal electrical activity has quieted down, but the patient has not yet returned to normal. This phase lasts minutes to hours. Common abnormalities during the post-ictal phase include disorientation, incoordination, and blindness. A small percentage of animals become aggressive after a seizure. Do not try to comfort or calm your pet. Isolate yourself or your pet so that nobody gets hurt. Some patients will eat or drink ravenously, vomit, urinate, or defecate. Post-ictal aggression occurs occasionally. You should see your veterinarian if your pet has not returned to normal within 24 hours.

Prodrome: The prodrome is a long-term (hours to days) indication of an impending seizure. A prodrome is not observed or recognized by most owners. Clinical signs of a prodrome include restlessness, vocalizing, clinginess, or hiding.

What Do I Do When My Pet is Having a Seizure?

First of all, DON’T PANIC! Yes, that’s easier said than done! However, it is very uncommon for a pet to die during or directly because of a seizure. They are usually short and stop by themselves, lasting about 2-3 minutes on average. You don’t need to do anything other than keep your pet safe. Pull her away from the top of the stairs if needed so she doesn’t fall down the stairs, or pull her away from furniture if she is hitting the furniture. Do not try to pull the tongue out thinking that she may “swallow” the tongue. This doesn’t happen, and you’re likely to be bitten, which can cause serious injury and possibly put you in the hospital. Do not try to cuddle or hold your pet. Dogs and cats are sometimes aggressive during or after a seizure, and you could be injured. Let them be. This usually resolves on its own.

When Are Seizures an Emergency?

There are two situations that require immediate emergency treatment. The first is any active seizure (ictus) lasting longer than five minutes. This is called status epilepticus. We start to worry about irreversible brain changes when the active seizure phase lasts longer than 30 minutes. The second emergency situation is cluster seizures, in which there are 3 or more seizures in a 24-hour period. These can become life-threatening because they can progress into status epilepticus.

Seizure Logbook

We recommend that you keep a logbook documenting all of your pet’s seizures, including time of day, duration, any potential triggers, what the seizure looked like, etc. Bring the logbook with you to your veterinary appointment. With everyone’s busy schedules these days, it is very difficult to remember the details of the seizures with any accuracy. The logbook greatly assists the veterinarian with decision-making regarding recommended tests and medications.

When Should I Seek Veterinary Care?

You should see a veterinarian after your pet’s first-ever seizure. Your veterinarian will ask you about any potential toxin exposure and likely recommend blood tests to rule out diseases outside the brain that can trigger seizures. This usually involves a complete blood count, biochemical profile, and bile acids (liver function) test. The blood tests also provide a baseline before starting medications. Additional blood tests (e.g., lead level) may be recommended depending on your pet’s history.

What Other Tests Are Performed?

Your veterinarian will make additional recommendations based on a variety of factors, including your pet’s age, breed, medical history, and neurologic exam findings. Ideally, MRI and sometimes other tests would be performed on every dog or cat with seizures, but these are not always necessary and, in veterinary medicine, we have to weigh the benefits to risk ratio of anesthesia/MRI/spinal tap vs. the associated costs of the procedures. Additional tests are usually recommended when the patient is less than one year of age, older than 5-6 years of age, if there are any abnormalities noted between seizures at home or on neurologic exam, or if the seizures are difficult to control. Dogs in the 1-5 year age range may have

When Do I Start Anticonvulsants and How Effective Are They?

There’s no 100% correct answer as to when to start anti-seizure medications. In general, most neurologists recommend starting an anticonvulsant if there is more than one seizure every 3-6 months or if there is an underlying progressive disorder. We also start anticonvulsants immediately in any patient that has status epilepticus or cluster seizures from the beginning. There are many medication options available that are very safe if used and monitored appropriately. Approximately 75-80% of dogs with Idiopathic Epilepsy can be controlled with one or two anticonvulsants. By “controlled” we mean no more than one seizure every 2-3 months or so. It’s possible that the seizures stop entirely with medication(s), but many patients continue to have seizures from time to time. Our goal is to give your pet the best quality of life by reducing the seizure frequency/duration/severity as much as possible while minimizing side effects of medications. The degree of improvement for other seizure disorders depends on the underlying cause and success of treatment.

What About CBD Oil / Medical Marijuana?

There is a difference between cannabidiol (CBD) and marijuana. CBD is a non-psychoactive compound found in marijuana that is thought to alleviate pain and to help control seizures. There is a great deal of anecdotal information suggesting that CBD may help patients with seizures. Recent studies in human medicine have shown improvement in seizure control with a few very specific epilepsy disorders. At this time, veterinarians cannot make any accurate statements about CBD because there are no peer-reviewed, placebo-controlled studies in dogs and cats to determine the correct dosing, potential adverse effects, or effectiveness of CBD oil for epileptic dogs and cats. One study from the 1980s showed that CBD has very limited absorption from the GI tract into the bloodstream in dogs, so it might not even reach high enough concentrations in the brain to be effective.

Since marijuana is a federally-registered schedule I controlled substance in the USA, veterinarians are unable to prescribe medical marijuana to pets. In states where marijuana has been legalized, veterinarians are either prohibited from prescribing it, or the law is unclear. Regardless, THC, the compound in marijuana that causes the high, is toxic to animals so please DO NOT give your pet marijuana in any form.

Are There Other Alternative Treatments?

A recent study found improvement in seizure control when feeding dogs a diet with increased content of medium chain triglycerides. However, there is conflicting data or limited peer-reviewed studies examining the effectiveness of other therapies. Most reports are just anecdotal accounts of treatment success, so be very skeptical about exaggerated claims of success and consult with your veterinarian before trying anything you read about online.

 

We understand seeing your pet have a seizure is scary and heartbreaking. Remember we are here for both you and your pet should you need us.

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