Are horse age and incision length associated with surgical site infection following equine colic surgery?

•Surgicalsite infection (SSI) occurred in approximately 20% of horses undergoing colic surgery.•SSI was significantly different between breeds (P 0.05).•SSI was associated with procedures likely to involve heavier contamination of the surgical site.•Horses with longer incisions and with signs of colic postoperatively had a higher SSI rate.•Horses that received extended antimicrobial prophylaxis (>24 h) did not have a lower SSI. It is our clinical impression that age and incision length are more strongly associated with surgical site infection (SSI) following colic surgery than skin closure or wound protection method. Therefore, the objective of this observational clinical cohort study was to identify the risks for SSI in horses undergoing colic surgery. Data collection included pre-, intra-, and postoperative variables. Variables with P