Efficacy of olanexidine gluconate in canine superficial pyoderma: a randomised, single-blinded controlled trial.

BACKGROUND: Topical treatments can be beneficial for managing canine superficial pyoderma. A novel antiseptic agent, olanexidine gluconate, has become available recently for use in humans, and its efficacy for canine pyoderma as topical therapy is unknown. OBJECTIVE: The antimicrobial effect of olanexidine was evaluated using minimal inhibitory concentration (MIC) towards Staphylococcus pseudintermedius. Furthermore, its clinical efficacy in canine superficial pyoderma was assessed in a randomized, single-blinded study. ANIMALS: Twenty-eight client-owned dogs with atopic dermatitis and superficial pyoderma. METHODS AND MATERIALS: The MIC of olanexidine was determined for S. pseudintermedius isolates (n=73) by serial dilution of 96-well broth microdilution method. Regarding the clinical trial, all recruited dogs were randomized into two groups; one treated with 1.5% olanexidine spray once daily and the other with a 3% chlorhexidine shampoo once a week for 2 times, respectively. Clinical assessment was performed at days 0 and 14 according to the guidelines of the Japanese Society of Antimicrobials for Animals. RESULTS: The MIC values for methicillin-resistant S. pseudintermedius (MRSP) and methicillin-sensitive S. pseudintermedius (MSSP) were 0.23 µg/ml and 0.24 µg/ml (P =0.9), respectively. In clinical trial, olanexidine and chlorhexidine showed substantial improvement in clinical presentation compared to the baseline. CONCLUSIONS AND CLINICAL IMPORTANCE: Olanexidine showed comparable efficacy to chlorhexidine (P=0.73). Moreover, the MIC against S. pseudintermedius indicated high bactericidal activity, which was supported by the topical effectiveness of olanexidine.