Comparison of Chlorhexidine and Alcohol-Based Skin Antisepsis in Cattle. Doyle AJ1, Saab ME2, McClure JT1. 1University of Prince Edward Island, Department of Health Management, Charlottetown, PE, Canada; 2University of Prince Edward Island, Diagnostic Services, Charlottetown, PE, Canada.
Alcohol-based antisepsis (ABA) has been confirmed to be as effective as 4% chlorhexidine gluconate (CHG) at reducing bacterial counts on equine skin. Studies in cattle comparing ABA to CHG have not been performed. Our objectives were to determine skin tolerance, posttreatment reduction (immediate effect), and 1 h posttreatment reduction (sustained effect) of aerobic bacterial counts following ABA and CHG antisepsis in cattle. Eighteen cattle were used. Three sites in each paralumbar fossa were clipped and randomly assigned to three treatment groups: 5 min scrub using 4% chlorhexidine gluconate (CHG); 90 s scrub using 80% ethanol (ET); 90 s scrub using 70% isopropyl alcohol (IPA). Samples were collected pre-, post-, and 1 h posttreatment and plated in duplicate. Bacterial counts were shifted to eliminate zeroes, log10 transformed, and averaged. ANOVA was used to compare differences in mean reduction in log10 CFU/mL between treatment groups. CHG had less immediate log10 CFU/mL reduction when compared to IPA (P = 0.001) and ET (P = 0.001). Immediate reduction between IPA and ET were not different. CHG demonstrated a greater sustained reduction compared to ET (P = 0.005). Sustained reduction between CHG and IPA and between IPA and ET were not different. No skin reactions were noted. A limitation of the study was researchers were not blinded to treatment during sample collection. This study showed ABAs were well tolerated and performed better than CHG in immediate bacterial reduction in cattle. CHG performed better than ET at 1 h post treatment, but there was no significant difference in the sustained effect of CHG and IPA.