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Multimodal Management of Epilepsy

  • September 20, 2017 11:25 AM EDT

    Epilepsy is the most common chronic neurologic disorder of dogs and manifests as focal or generalized seizure activity. Affected dogs may also exhibit other behavioral problems (ADHD-like including anxiety, aggression, poor trainability). The condition can develop due to a genetic predisposition for the disease or secondarily in association with other problems including structural abnormality in the brain, trauma, infections, or toxin exposure. The cause of epilepsy in a dog is often undetermined and is coined "idiopathic."

    Triggers for seizures in a dog with epilepsy are variable and can be physiologic in origin or as a consequence to stress. It’s also been demonstrated that the seizure events themselves are quantifiably stress-inducing on both the pet and the owner. A recently published study reported significant differences in cortisol levels in dogs (265.1% increase) and in their owners (40.5% increase) - at 40 & 20 minutes post-seizure, respectively - compared to time-matched points on the following (non-seizure) day.

    An accurate diagnosis of the condition, the cause, as well as classification of the type(s) of seizures the pet experiences is helpful for formulating a treatment plan for the affected dog. Most dogs respond favorably to therapy, however it’s been reported that roughly 30% of dogs are refractory to treatment or have poor seizure control. These dogs are at a higher risk of premature death. Furthermore, poorly controlled disease has an adverse effect on the quality of life of not only the affected pet but its owner, too.

    Unfortunately there is no cure for this condition and the goal of treatment is to minimize or prevent recurrence of seizures. As with most diseases or conditions a holistic, multimodal approach to the care and management of epilepsy is essential to the pet’s well being. This includes:

    • Minimizing potential seizure triggers
    • Minimizing stress
    • Administering antiepileptic drugs or other pharmacotherapy
    • Ensuring good nutrition

    Antiepileptic Drugs and Pharmacotherapy

    Pharmacological intervention is essential to managing patients with epilepsy. Antiepileptic drugs (AEDs) are given in an attempt to minimize or prevent seizures, and these drugs may be used as monotherapy or in combination in patients that are poorly controlled or that demonstrate pharmacoresistance.

    These drugs include (ranked in descending order of efficacy as a monotherapy agent and/or levels of evidence supporting use):

    • Phenobarbital or Imepitoin
    • Potassium Bromide
    • Levetiracetam or Zonisamide

    It’s been reported that phenobarbital alone may control seizures in approximately 85% of treated dogs and that bromide alone may control seizures in approximately 52% of treated dogs. We can, however, see drug resistance in some animals. Risk factors for antiepileptic drug resistance include:

    • Sex (males are at higher risk)
    • Animals that are prone to cluster seizures
    • Certain breeds have demonstrated a resistance or poorer response to AEDs including the Border Collie, German Shepherd Dog, Staffordshire Bull Terrier, and Labrador Retriever
    • Concurrent allergic disease (skin or GI) may possibly contribute to AED resistance

    “Food as Medicine?”

    Manipulation of the diet, foodstuffs, and dietary supplements are known to greatly benefit patients managed for a variety of diseases (e.g. inflammatory bowel diseaseosteoarthritis, cancer, etc.).

    In the case of epilepsy:

    • Omega-3 fatty acids

    Studies in humans with epilepsy have shown conflicting results as to efficacy of omega-3 fatty acid supplementation, and studies in dogs are very limited, though a case study of one dog did demonstrate a positive effect.

    Omega-3s may have anticonvulsant properties due to their affect on voltage-dependent sodium channels (inhibition) and their known anti-inflammatory effects.

    • Diet

    Alteration of the diet and its composition has been shown to benefit humans with epilepsy. Specifically, diets high in fat and low in carbohydrate and protein have shown to benefit children with epilepsy. These diets are ketogenic - meaning that when consumed, ketone bodies are produced with a concurrent increase of levels in the brain. It’s not completely understood why a low carb / ketogenic diet might help with seizure control, but theories include inhibition of certain metabolic pathways, improved energy metabolism in neurons, alteration in neuronal sensitivity, and inhibition of glutamatergic synaptic transmission. 

    A 2005 study of dogs with drug-resistant epilepsy and fed a ketogenic diet failed to demonstrate a difference in seizure control as compared to dogs fed a placebo diet. (Patterson E, Munana K, Kirk C, et al. Results of ketogenic food trial for dogs with idiopathic epilepsy. [abstract]. J Vet Int Med 2005;19)  

    It’s believed that dogs do not easily become ketotic (as compared to humans) when fed diets high in fat that is comprised of long chain triglycerides. Medium chain triglycerides (MCTs), on the other hand, are fatty acids found in coconut oil and palm kernel oil, and when metabolized MCTs form ketone bodies.

    In this week’s Specialty Update we report on the interesting findings of a study of dogs with epilepsy that were fed a diet rich in MCTs. These findings were recently discussed at the AKC Canine Health Foundation National Parent Club Canine Health Conference, along with some exciting information about the effect of MCTs on the behavior comorbidities in these dogs.  

    View this specialty update (running time 7 mins) and enjoy this preview:

    Additional Resources:

    Understanding Canine Epilepsy from the AKC Canine Health Foundation

    2015 ACVIM Small Animal Consensus Statement on Seizure Management in Dogs