The primary objective of this study is to determine if obesity is a risk factor for the development of surgical site infection (SSI) and predictive of outcome following emergency ventral midline celiotomy. We hypothesize that horses with higher body mass index (BMI) have a greater odds of developing SSI and decreased long-term survival compared to horses with lower BMI following emergency abdominal surgery. We propose testing our hypothesis in two phases. Phase I will be a retrospective evaluation of medical records for all horses that have undergone a ventral midline celiotomy during the last six years and we will determine the incidence of SSI in this cohort and associate the development of SSI with the patient’s BMI. Specifically, the BMI of horses who developed SSI will be compared to the BMI of horses that did not. A crude odds ratio will be calculated to determine if BMI is an independent risk factor for SSI development. If BMI is associated with SSI development, we plan to initiate Phase II where we will prospectively evaluate clinical and clinicopathologic parameters related to adiposity in order to determine which, if any, are predictive of SSI and outcome following emergency abdominal surgery.