The goal of this study was to evaluate the efficacy of phenobarbital or potassium bromide (KBr) as add-on antiepileptic drugs for controlling dogs refractory to a maximum dose of imepitoin (30 mg/ kg twice daily). The study was performed as a prospective, randomised, controlled clinical trial. The efficacy of phenobarbital and KBr was evaluated by comparing monthly seizure frequency (MSF), monthly seizure day frequency (MSDF), the presence of cluster seizures during a retrospective 2-month period with a prospective follow-up of 6 months, and the overall responder rate.
