EPIDEMIOLOGIC EVALUATION OF POSTOPERATIVE WOUND INFECTIONS IN DOGS AND CATS

Objective - To determine postoperative wound infection rates in dogs a nd cats for various wound contamination categories and to identify fac tors that influence postoperative wound infection rates. Design - Epid emiologic study. Sample Population - 1,574 wounds in 1,255 dogs and ca ts. Procedure - Information recorded included signalment, nutritional status, surgery duration, surgical procedures, wound contamination cla ssification, interval from clipping until surgery, blood pressure valu es, active infection at a distant site, endocrinopathy, and administra tion of immunosuppressive medications or antibiotics. Relative risk, 9 5% confidence intervals, and multiple regression analyses were perform ed, Results - Postoperative infection was evident in 86 of 1,574 (5.5% ) wounds, including 54 of 1,146 (4.7%) and 13 of 259 (5.0%) animals wi th clean and clean-contaminated wounds, respectively, and 12 of 100 (1 2.0%) and 7 of 69 (10.1%) animals with contaminated and dirty wounds, respectively. Animals with clean wounds that received antibiotics othe r than as prescribed in our perioperative protocol had a higher infect ion rate than animals that did not receive antibiotics, Surgical sites clipped before anesthetic induction were 3 times more likely to becom e infected than sites clipped after induction. Risk of wound infection increased with increasing duration of surgery. Clinical implications - Wound contamination categories had too much variation to make them u seful for predicting animals that would develop wound infections. Surg ical sites should be clipped immediately prior to surgery, and intraop erative time should be kept to a minimum.,Unless indicated for other c urrent active infection, prolonged use of antibiotics after surgery sh ould be avoided in animals with clean wounds.