Neurologic Breakthrough in Canine Nutrition

Veterinarians in companion animal practice are familiar with canine idiopathic epilepsy, a neurologic condition that affects an estimated 1 in 111 dogs.¹ Companion animal practitioners are also familiar with the shortcomings of current therapeutic approaches, which include medication side effects and breakthrough seizures.

While the precise cause of canine idiopathic epilepsy is unknown, the effect in the brain has been documented as a rapid, uncontrolled discharge of neurons within the brain’s cerebral cortex that leads to seizures.² Epilepsy appears to be a heritable condition in dogs; while any dog of any breed can develop the condition, some breeds are predisposed. These include Labrador retrievers, Belgian shepherds, petit Basset Griffon vendeens, boxers, Irish wolfhounds, English springer spaniels, vizslas, Bernese mountain dogs, standard poodles, border collies, Australian shepherds, and border terriers.³ The condition is also more common in males than females, with neutering having no effect on this predisposition.²

Anti-epilepsy drugs (AEDs) such as phenobarbital and potassium bromide are commonly used for canine epilepsy.² Patients typically have their first seizure between 1 and 3 years of age⁴ and begin treatment with one of these medications, with others added if and when treatment results are unsatisfactory (a 50% reduction in seizures is considered a successful response⁵). The challenge: two-thirds of affected dogs continue to suffer from seizures in spite of medication,⁶ and 20% to 30% remain poorly controlled.^7–9 Meanwhile, AEDs themselves are associated with side effects, including polyphagia, polydipsia, polyuria, restlessness, lethargy, and ataxia, leading veterinarians to walk a narrow line between achieving medication benefits and causing harm. As a result, only 4% of veterinarians surveyed are “totally” or “mostly” satisfied with current treatment options.¹

While the precise cause of canine idiopathic epilepsy is unknown, the effect in the brain has been documented as a rapid, uncontrolled discharge of neurons within the brain’s cerebral cortex that leads to seizures.

Dietary Therapy: A New Approach to Managing Dogs With Epilepsy?

Traditional ketogenic diets, which are designed to force the body to burn fat instead of carbohydrate and put the body into a state of ketosis, have been used for decades in children whose seizures are not controlled with medication.¹⁰ The rationale is that brain glucose metabolism, which allows for production of adenosine triphosphate (ATP) as well as substrates for the generation of neurotransmitters,¹¹ is disrupted in epileptic patients, creating a need for alternative sources of brain energy.^11–16

While high-fat, low-carbohydrate diets utilizing long-chain triglycerides have been used and studied in children, this type of diet has yet to be shown to significantly improve seizure control in dogs.¹⁷ In addition, such diets also are unsatisfactory from a nutrient and palatability standpoint for dogs requiring lifelong therapy. Fortunately, dogs can metabolize medium-chain triglycerides (MCTs) to produce ketones,¹⁸ and experts believe that dietary MCTs may also have direct antiseizure effects via blocking the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors in the brain.¹⁹ Diets supplemented with MCT oil for dogs can also be formulated with lower amounts of fat and higher proportions of protein and carbohydrates than traditional ketogenic diets—an important factor when a diet needs to be fed for the remainder of a dog’s life.

Epilepsy Study Examines the Effects of Test Diet With Mct Oil on Seizures

Neurologic researchers at the Royal Veterinary College (RVC), in partnership with Purina, recently investigated the potential role of diet in the nutritional management of dogs whose seizures were not being well controlled with AEDs. While achieving complete remission was not considered realistic for many patients, the goal was to reduce seizure frequency in epileptic dogs on chronic AED therapy.

A total of 21 dogs with idiopathic epilepsy that had experienced at least 3 seizures in the 3 months prior to enrollment completed a 6-month, randomized, placebo-controlled, double-blinded crossover study at the RVC. The study demonstrated for the first time that a test diet with MCT oil can have positive effects on reduction of seizure frequency when fed as an adjunct to veterinary therapy.¹⁸ Dogs in the 2 groups were fed either a test diet containing MCT oil or a placebo diet for a period of 3 months—then switched to the other diet. In the study, the following results were noted:

—  71% of dogs showed a reduction in seizure frequency

—  48% of dogs showed a 50% or greater reduction in seizure frequency

—  14% of dogs achieved complete seizure freedom

Diet Helps Nutritionally Manage Dogs With Epilepsy as an Adjunct to Veterinary Therapy

The results of this study inspired Purina to develop the Purina^® Pro Plan^® Veterinary Diets NC NeuroCare^™ diet, which is formulated with MCT oil to help nutritionally manage dogs with epilepsy that are also being administered AEDs. The diet is enhanced with a unique blend of nutrients—eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), arginine, antioxidants, and B vitamins, as well as MCT oil—to promote cognitive health and help nutritionally manage dogs with cognitive dysfunction syndrome.