Influence of clipping on bacterial contamination of canine arthrocentesis sites before and after skin preparation.

Objective To determine the influence of hair removal as part of the aseptic skin preparation of canine arthrocentesis sites and to characterize the bacterial flora remaining after aseptic skin preparation. Study design Randomized controlled trial. Study population Thirteen shorthaired beagle-cross dogs. Methods A coin toss was used to randomly determine to have one carpus, elbow, tarsus, and stifle clipped. The contralateral side was left unclipped. Aseptic skin preparation was performed on all sites with 4% chlorhexidine followed by 70% isopropyl alcohol. The skin of each site was sampled for aerobic and anaerobic bacterial cultures before and after aseptic skin preparation. Bacterial cultures were submitted for laboratory testing to determine the colony-forming units (CFU) of bacteria and bacterial species isolated for each site. Results Each group (clipped and unclipped) included 52 sites. Aseptic skin preparation reduced bacterial CFU in both groups. There was no association between values for CFU per milliliter after skin preparation of dogs and side (P = .07), joint (P = .71), pre-aseptic skin preparation CFU (P = .94), or clipping (P = .42). Staphylococcus spp were the most common of the bacterial species cultured. Conclusion In clean shorthaired dogs without visible evidence of dermatological disease, leaving arthrocentesis sites unclipped rather than performing traditional surgical clipping did not result in increased bacterial skin counts after aseptic skin preparation. Clinical significance In this study we did not find evidence to support that clipping of canine arthrocentesis sites is required for effective aseptic skin preparation. A prospective clinical trial is required to determine whether a change in practice would be associated with increased morbidity.