Risk factors for surgical site infection associated with clean surgical procedures in dogs

Surgical site infection (SSI) is associated with increased morbidity, cost and mortality in human medicine and with increased morbidity and cost in veterinary medicine. The aim of this study was to evaluate risk factors for SSI development after clean surgical procedures in dogs, treated at both first opinion clinics as well as referral hospitals. 1550 dogs scored 1 or 2 according to the American Society of Anesthesiologists (ASA), that underwent clean surgical procedures at 103 clinics located in Northern and Central Europe were included in the study. Data regarding the surgical procedure, surgery time use of perioperative antimicrobial prophylaxis (AMP), surgery type, intraoperative hypothermia, and the use of surgical implants were recorded according to predefined protocols. Active 30-day SSI surveillance was performed. A random effects logistic regression model was used to evaluate the association between the perioperative variables and SSI development. SSI was detected in 85/1550 dogs (5.5%); 25 occurred in the 500 orthopedic/neurosurgery procedures (5.0%), and 60 in the 1050 soft tissue procedures (5.7%). A total of 1524 dogs were included in the final multivariable model. Increased surgery time was the only variable associated with an increased risk of SSI. No association between the other risk factors evaluated in the study and SSI occurrence was detected. Efforts must therefore be made to keep the surgery time as short as possible. Orthopedic and neurosurgical procedures including those where an implant is placed should not automatically be regarded as high-risk procedures benefiting from perioperative AMP.