Factors associated with surgical site infections in horses a retrospective study

Post-operative surgical site infection (SSI) is a significant complication in equine surgery. This demonstrates an urgent need to broaden our knowledge and capabilities regarding SSIs. The current study evaluates the incidence, the bacteria involved and possible risk factors for equine surgery SSIs in our hospital (Koret School of Veterinary medicine, Department of Large Animal Medicine and Surgery). All 198 surgical procedures performed in 167 horses between November 2011 and February 2013, were included in the study. The parameters evaluated were: type of surgery, the surgeons involved, age, weight, sex, breed of the animal, duration of the procedure, time of day the procedure was performed, season and duration of hospitalization. The general incidence of infection during the study period was 16.7%. Risk factors were: type of surgery, repeat surgery, sex, and weight. Abdominal procedures had a higher risk of developing SSI than other procedures. Pregnant mares had higher risk of developing an infection than others. Heavier body weight increased the risk for the development of SSIs as well. Nineteen samples were sent for culture and sensitivity, and the most common bacteria isolated were Methicillin resistant Staphylococcus aureus (MRSA) and Pseudomonas aeroginosa. According to the uni-variable analysis, the factors that were found to have an association with SSI, were the weight of the patient, the type of surgery, repeat surgery, sex and reproductive state and hospitalization time. The logistic regression test found that the patient’s weight, repeat surgery, type of surgery and sex and reproductive state of the patient had a direct effect on the development of SSI.