Comparison of once-daily versus twice-weekly terbinafine administration for the treatment of canine Malassezia dermatitis - a pilot study

Background – Terbinafine, an allylamine antifungal, is used in pulsatile dose regimens for superficial mycoses in human medicine. Objectives – To compare the clinical efficacy of twice‐weekly versus once‐daily terbinafine administration to determine whether preliminary proof‐of‐concept evidence exists for pulsatile administration of terbinafine in the treatment of canine Malassezia dermatitis and to determine whether twice‐weekly treatment results in fewer clinical and owner‐perceived adverse events. Animals – Twenty client‐owned dogs with Malassezia dermatitis. Methods – In this randomized, single‐blinded clinical trial, dogs were randomly assigned to receive terbinafine (30 mg/kg) either once daily for 21 days (n = 10) or once daily on two consecutive days per week for six doses (n = 10). On day 0 and day 21, a mean yeast count was calculated from eight anatomical locations via adhesive tape‐strip cytology, clinical lesion scores were assigned to the same locations, and owners assessed pruritus using a visual analog scale. Results – There was no significant difference between treatment groups with respect to the reduction in mean yeast count (P = 0.343) and clinical lesion scores (P = 0.887). Pruritus measured by visual analog scale was significantly decreased in the twice‐weekly treatment group compared with the daily treatment group (P = 0.047). Seven of 20 dogs had a clinically measurable or owner‐reported adverse event during treatment that included gastrointestinal disturbances, excessive panting and elevated hepatic enzymes, with no significant difference noted between treatment groups. Conclusions and clinical importance – This pilot study indicates that twice‐weekly terbinafine administration may be an effective alternative treatment for canine Malassezia dermatitis and merits further investigation.