Wound Healing in Rainbow Trout following Surgical Site Preparation with a Povidone–Iodine Antiseptic

Abstract

We investigated the effects of preparing surgical incision sites with a topical antiseptic on wound healing and hematological response in rainbow trout Oncorhynchus mykiss. A povidone–iodine solution was applied both pre- and postsurgery to the incision sites on treated fish. Three-centimeter incisions in both treated (N = 9) and control (nontreated, N = 9) fish were closed with four nonabsorbable sutures sewn in a simple interrupted pattern. During the 42-d period of wound healing, there were no statistically significant changes in total erythrocyte counts (1.28 × 10⁶/mm³ ± 0.05 SE), in percentage of dividing erythrocytes (0.76% ± 0.07 SE), or in differential leukocyte counts. Postmortem, pathogenic bacterial infections in the kidney or spleen were not detected in any of the fish. There was no histological difference between control and treated incisions to show either beneficial or adverse tissue reactions to the topical antiseptic treatments. Blinded histological analysis revealed both treated and untreated incision sites healed within 42 d at the same rate. Therefore, preparation of the incision sites with a povidone–iodine antiseptic did not improve wound healing nor alter healing rate in rainbow trout under the conditions of this study.