Peritonitis in horses: 55 cases (2004-2007)

Factors associated with the outcome of peritonitis in horses are seldom described. The objectives of this study were to determine the common clinical signs and clinicopathologic findings and to reveal prognostic factors associated with the outcome of peritonitis in equine patients. Data were examined in a retrospective manner in 55 horses diagnosed with and treated for peritonitis. The most common clinical and clinicopathologic findings were tachycardia (94%), increased amount of peritoneal fluid on ultrasound (84%), altered mucous membranes (82%), bacteria noted on the direct smear (67%), hyperfibrinogenaemia (58%) and left shift (40%). The most commonly isolated organism was E. coli (37%). Survival rates were as follow: 78% in the whole study, 81% in the abdominal lavage group, 93% in the medically and 46% in the surgically managed groups. Complications were more common in the non-survivor group (P < 0.001). Initial haematocrit and surgical interventions were strongly associated with non-survival in the multivariate logistic regression model (P = 0.049, OR: 1.07 and P = 0.01, OR: 9.87, respectively). Prognosis of peritonitis without gastrointestinal rupture depends on the initial hydration status, surgical interventions and development of secondary complications, while other clinical and clinicopathologic findings do not appear to correlate with survival. Prospective evaluation of hydration and perfusion parameters and abdominal lavage warrants further investigation.