Topical ethyl alcohol as a novel treatment for superficial bacterial pyoderma in dogs

Objectives To assess topical ethyl alcohol as a novel treatment for canine superficial pyoderma and compare its effects with chlorhexidine digluconate on the relative abundance of Staphylococcus pseudintermedius and Staphylococcus schleiferi within the skin microbiome. Materials and Methods In this prospective, randomised, blinded study, 15 client‐owned dogs with bilaterally symmetric bacterial skin lesions received twice‐daily topical chlorhexidine digluconate 3% (Douxo™ S3 Pyo mousse, CEVA; Libourne, France) or 70% ethyl alcohol (Purell™ Gel, GOJO Industries; Wooster, OH, USA) for 28 days. Lesions were clinically and cytologically scored at days 0, 14 and 28 using a modified split‐body system to generate a global score. Next‐generation DNA sequencing characterised the S. pseudintermedius and S. schleiferi loads at day 0 and 28. Results Both treatments significant improved global scores from baseline (chlorhexidine 18.22 ± 3.54; ethyl alcohol 17.95 ± 3.78) at 14‐days (chlorhexidine 12.80 ± 2.74, p ≤ 0.001; ethyl alcohol 12.40 ± 3.06, p ≤ 0.001) and 28‐days (chlorhexidine 9.24 ± 3.57, p ≤ 0.001 and ethyl alcohol 8.40 ± 4.06, p ≤ 0.001). Global scores were not significantly different between treatment groups at any time point. Both treatments also reduced the relative abundance of S. pseudintermedius (chlorhexidine −28.73% ± 42.86%; ethyl alcohol −25.66% ± 38.74%) and S. schleiferi (chlorhexidine −65.93% ± 13.03%; ethyl alcohol −79.82% ± 8.37%). No statistically significant differences were observed in the relative abundance of either species between the topical treatments ( p =0.95 S. pseudintermedius ; p =0.38 S. schleiferi ). Clinical Significance This study suggests topical 70% ethyl alcohol may be an effective treatment for canine superficial pyoderma.