Evaluation of systemic inflammatory response syndrome criteria in horses with colic associated with acute gastrointestinal disease

Background: Systemic inflammatory response syndrome (SIRS) is a severe clinical condition commonly observed in horses with acute gastrointestinal disease associated with colic and is linked to increased risk of organ dysfunction and mortality. Early identification of SIRS and reliable prognostic indicators are essential to improve clinical management. This study aimed to assess the occurrence of SIRS in adult horses with colic, evaluate its association with outcome, and investigate the prognostic value of selected clinicopathological variables. Materials and methods: A total of 41 adult horses admitted for acute gastrointestinal disease were included. Clinical, hematological, and biochemical data were collected at admission. A SIRS score (0-6) was calculated based on temperature, heart rate, respiratory rate, white blood cell count, blood lactate concentration, and mucous membrane characteristics. Horses were classified as SIRS-positive (≥2 criteria) or SIRS-negative. Outcomes were recorded as survivors (SUR) or non-survivors (NSUR). Statistical analyses included group comparisons and linear regression to evaluate associations between variables and survival. Results: SIRS was identified in 58.5% (24/41) of horses. Mortality was significantly higher in the SIRS-positive group (50%) compared to the SIRS-negative group (11.7%). SIRS-positive horses showed increased heart and respiratory rates and significant eosinopenia. Among SIRS-positive horses, non-survivors had significantly higher blood lactate concentrations than survivors (p = 0.04). Linear regression analysis demonstrated a significant inverse relationship between eosinophil count and survival time, indicating that higher eosinophil levels were associated with shorter survival. Conclusion: SIRS is associated with increased mortality in horses with acute gastrointestinal disease. Blood lactate concentration and eosinophil count emerged as relevant prognostic indicators. The combined use of SIRS scoring and selected laboratory parameters may support early risk stratification and clinical decision-making in equine emergency medicine. Further prospective studies are needed to confirm these findings.