Abstract
Background:
The anti-epileptic effects of docosahexaenoic acid (DHA) in dogs and humans remain controversial. The dosage and efficacy of DHA were various in the previous reports.
Aim:
The effects of high-dose DHA supplementation as add-on therapy for idiopathic epilepsy in dogs were evaluated.
Methods:
An open-label clinical trial was designed in this pilot study. Six dogs (median age: 6 years) with idiopathic epilepsy were included. All the patients were diagnosed with idiopathic epilepsy using magnetic MRI and cerebrospinal fluid examination (median: 2.0 years before the trial). They had 5–45 seizures and/or auras (median: 9.0) in the month before starting DHA supplementation. DHA was adjunctively administered at doses of 69–166 mg/kg/day without changing other prescriptions.
Results:
Four of the six patients completed the 6-month observation period. All the patients showed a decrease in seizure frequency of 50% or more within 2–3 months after the start of the administration, and three patients decreased to a frequency of 0–1 per month after 5–6 months. No clear adverse events were observed in the general condition or blood test results in any patients.
Conclusion:
Although the sample size was small and the study was not a randomized controlled trial, the data suggest that add-on supplementation of DHA could be useful in reducing the frequency of seizures in canine idiopathic epilepsy.

Key words: Docosahexaenoic acid, Dogs, Drug-resistant epilepsy, Idiopathic epilepsy, Omega-3 fatty acids