Effectiveness of chlorhexidine diacetate and povidone-iodine in antiseptic preparation of the canine external ear canal prior to total ear canal ablation with bulla osteotomy procedure: A preliminary study

This article is a preliminary study to compare the ability of 0.05% chlorhexidine diacetate (CD) and 1% povidone-iodine (PI) solutions to reduce bacterial contamination on the canine external ear canal during initial patient preparation and comparison of the incidence of immediate tissue reactions. The study is a multi-institutional, randomised, clinical prospective study. Dogs (n = 19) undergoing total ear canal ablation with bulla osteotomy (TECABO). The external ear of each dog was cleaned with the assigned antiseptic solution. Culture of the ear was performed by standard techniques to semi-quantitatively evaluate bacterial growth and to identify bacterial organisms pre- and post-antiseptic use. Both antiseptic groups showed a significant reduction in bacterial growth score (BGS) between pre- and post-antiseptic use (CD p = 0.009, PI p = 0.005). There was no difference in the reduction of BGS between CD and PI solutions (p = 0.53). Minor adverse skin reactions occurred in 25% of cases. There was no significant difference in the occurrence of adverse skin reactions between antiseptics (p = 0.63). CD and PI were similarly able to decrease the number of bacteria on the external ear following initial preparation. No difference in the incidence of adverse tissue reactions was found. Properly diluted aqueous formulations of either antiseptic may be used for safe preparation limited to the external ear canal of dogs. Additional studies evaluating outcomes such as duration of bacterial inhibition and incidence of surgical site infections are needed to fully elucidate differences between CD and PI antiseptics prior to TECABO.