Evaluation of iodophor skin preparation techniques and factors influencingdrainage from ventral midline incisions in horses

Objective-To document natural bacterial flora on the ventral aspect of the equine abdomen, to compare 2 preparation techniques, and to identify potent ial risk factors that may contribute to incisional drainage. Design-Prospective study. Animals-53 horses undergoing exploratory celiotomy. Procedure-Group-1 horses (n = 26) were prepared with povidone-iodine and al cohol. Group-2 horses (27) were prepared with a film-forming iodophor compl ex. Numbers of bacterial colony-forming units (CFU) were measured before an d after surgical scrub, following skin closure, and after recovery from gen eral anesthesia. Swab specimens to identify normal skin bacterial flora and potential pathogens were obtained by swabbing a 4 x 4-cm area. Variables t hat might affect incisional drainage were also investigated. Results-For both techniques, there was a significant reduction in bacterial numbers after skin preparation. Incisional drainage was observed in 14 (26 %) horses (8 group-1 and 6 group-2 horses). Preexisting dermatitis, poor in traoperative drape adherence, high number of bacterial CFU obtained after r ecovery from anesthesia, and high number of CFU obtained from the surgery r oom environment were the main risk factors associated with subsequent incis ional drainage. Bacillus sop, nonhemolytic Staphylococcus spp, Micrococcus sop, Corynebacterium spp, Streptomyces spp, other nonenteric genera, and no n-hemolytic Streptococcus spp were the most common isolates obtained before surgical scrub. Conclusions and Clinical Relevance-Both skin preparation techniques were eq ually effective in reducing numbers of bacterial CFU by 99%, and a signific ant difference was not found in incisional drainage rate between groups. Pr otection of the wound during recovery from anesthesia and the immediate pos toperative period may reduce incisional drainage after abdominal surgery in horses.