Predicting outcomes in equine peritonitis: Multivariable analysis of admission and post‐admission data from a
UK
hospital population
E. K. Kopec, H. Carslake, D. C. Archer, B. Morris, A. Wilson Abstract
Background
Peritonitis is life‐threatening, and limited information exists regarding outcomes and predictors of survival.
Objectives
To report short‐ and long‐term outcomes in horses diagnosed with peritonitis and identify factors associated with survival.
Study Design
Retrospective observational.
Methods
Data were obtained for horses admitted to a UK referral hospital between 2010 and 2024 diagnosed with peritonitis (peritoneal fluid nucleated cell count >10 × 10 9 /L). Short‐ and long‐term morbidity and mortality were assessed. Multivariable logistic regression was used to identify factors associated with short‐term survival based on data available at admission (Model 1) and at the time of second abdominocentesis (Model 2).
Results
Peritonitis was diagnosed in 123 horses. Overall, short‐term survival was 74% (91/123) with better outcomes in primary (90%, 66/73) versus secondary peritonitis (50%, 25/50). Surgery was performed in 31 cases, with short‐term survival of 48% (15/31). In model 1, horses with higher heart rates (OR 0.90, 95% CI 0.86–0.95, p < 0.001) and sanguinous peritoneal fluid (OR 0.16, 95% CI 0.04–0.65, p = 0.01) were significantly less likely to survive to hospital discharge. Survival was better in ponies vs. horses (OR 8.30, 95% CI 1.42–48.60, p = 0.02), and if rectal examination was normal (OR 8.25, 95% CI 1.80–37.85, p = 0.007). In Model 2, increased heart rate was the best predictor of reduced survival (OR 0.89, 95% CI 0.83–0.94, p < 0.001). Survival to 30, 90, and 365 days was 98% ( n = 50/51), 93% ( n = 42/45), and 88% ( n = 35/40), respectively. A third of horses developed complications following hospital discharge (predominantly colic and pyrexia), usually within 90 days of hospital admission. Peritonitis recurred in 6 horses.
Main Limitations
Retrospective study from a single hospital population.
Conclusions
The prognosis for primary peritonitis is better than secondary peritonitis. Heart rate is a good predictor of short‐term survival at admission and time of repeat abdominocentesis.