Comparison of chlorhexidine and alcohol‐based antisepsis of the distal limbs of horses

Abstract

Background: An alcohol-based rub has been confirmed effective at reducing bacterial counts on equine skin. Skin sites with expected high bacterial burden have not been tested or has a comparison to a common protocol been performed. Objectives:To determine if ethanol-based antisepsis reduces bacterial counts on the equine distal limb comparable to a current chlorhexidine scrub method and determine the most effective application technique for the product. Study design: Randomised trial.Methods: Forty-one horses were used in the study. By horse, each limb was randomly assigned to a treatment group: 5min scrub using 4% chlorhexidine gluconate to a clipped site (CHG); 90s scrub using 80% ethanol to a clipped site (ETC); 90s contact with 80% ethanol applied as a spray to a clipped site (ETS) and 90s scrub using 80% ethanol to an unclipped site (ETUC). Samples were collected pre-and post-treatment and plated in duplicate. Bacterial counts were log 10 transformed and averaged between duplicates. A linear mixed model was used to compare mean log 10 CFU/mL reduction between groups. A cost-benefit analysis was performed.Results: There was no significant difference in mean log 10 CFU/mL reduction between CHG and ETC in either fore-or hindlimbs. In forelimbs, there was no significant difference in mean log 10 CFU/mL reduction between any groups. In hindlimbs, CHG had significantly greater mean log 10 CFU/mL reduction than ETUC and ETS. No significant difference in cost-benefit was found between CHG and ETC. Significant differences were noted between CHG and both ETUC and ETS.Main limitations: Researchers were not blinded to treatment group during sample collection. Conclusions:This study showed no significant difference in reduction in bacterial counts on the distal limb of horses between CHG and ethonol (ET) when applied as a scrub to a clipped site and there was no significant difference in cost-benefit between these treatments.

Comparison of chlorhexidine and alcohol‐based antisepsis on the paralumbar fossa in cattle

“…The lack of adverse skin reaction and similar performance of both alcohol‐based protocols when compared with the CHG protocol in our study provide evidence to support skin preparation with alcohol‐based antiseptics in cattle. Previous studies in horses have also confirmed the application of alcohol‐based antiseptics are well tolerated in veterinary species 7,8,10 . Pre‐existing dermatitis or the presence of wounds may increase adverse skin reactions and could potentially affect bacterial reduction when using alcohol‐based antiseptic protocols and further clinical investigation is warranted.…”

“…Previous studies in horses have also confirmed the application of alcoholbased antiseptics are well tolerated in veterinary species. 7,8,10 Pre-existing dermatitis or the presence of wounds may increase adverse skin reactions and could potentially affect bacterial reduction when using alcohol-based antiseptic protocols and further clinical investigation is warranted.…”

“…Previous reports have documented similar reduction in bacterial counts (colony forming units [CFU]) immediately after application of alcohol‐based antiseptics and CHG in horses; 7,8 however, these studies only tested an ethanol (ET) based product and did not test the sustained effect of this application. In cattle, no difference in perioperative CFU reduction was found between an antiseptic protocol alternating application of 4% CHG and alcohol and the application of a 0.5% CHG in 70% isopropyl alcohol (IPA) product 9 .…”