Abstract
Colic is a leading cause of mortality in horses, particularly when associated with systemic inflammation and organ dysfunction. In human medicine, these complications are associated with sepsis, defined as organ dysfunction caused by a dysregulated, life-threatening host response to infection. However, no consensus sepsis score exists for adult horses. This retrospective study aimed to develop a diagnostic sepsis score for adult horses. Medical records from 295 horses admitted for colic to the Oniris equine emergency department (Nantes, France) between July 2011 and November 2021 were analyzed. Horses were classified as having sepsis or colic based on their final diagnosis. Clinical and laboratory parameters were assessed, and univariate and multivariate logistic regression analyses yielded a predictive score. The optimal threshold was determined by maximizing sensitivity and specificity. Sepsis was diagnosed in 89 horses (30.2%). Six parameters-temperature, heart rate, leukocyte count, red blood cells, creatine kinase, and lactate-were included in the model. The score showed 79% accuracy, with 59% sensitivity and 88% specificity. At a threshold of 3, sensitivity was 52.7%, specificity was 91.6%, and the Youden index was 0.44. This study proposes a rapid, practical sepsis diagnostic score for adult horses with acute gastrointestinal disease, serving as a highly specific tool for confirming sepsis.