EquineReview

In a retrospective study in Vet Surg (2021; 50:323–335. 10.1111/vsu.13564 ) the authors aimed to identify etiology and other findings in horses with peritonitis and report factors associated with survival. They hypothesised there would be significant differences in clinicopathological variables between survivors and non-survivors. Essential inclusion criterion was peritoneal fluid with a white blood cell concentration of >25,000 cells/µL. Veterinary medical records over a 10-year period were examined. Horses presenting with gastrointestinal rupture, peritonitis after abdominal surgery or castration were excluded. The inciting cause, when known, was recorded; cases were considered idiopathic when no aetiology was determined. Long-term follow up was by telephone. A total of 72 horses matched the inclusion criteria. Colic was the most common complaint (47%), followed by fever, inappetence and trauma. Transabdominal ultrasound was performed in 96% of horses. Increased peritoneal fluid was present in 11/38 of horses that underwent ultrasound where other abnormalities were found. Actinobacillius equuli and Corynebacterium pseudotuberculosis were the most common bacteria cultured (24% and 20%, respectively). A definitive diagnosis was made in 61% of cases; the most common cause was infectious agents, followed by trauma, gastrointestinal thickening and eosino-phillic peritonitis. Of the surviving horses, 83% survived short-term and 88% were alive at one-year follow-up. Of the horses with a definitive diagnosis, 25% were euthanised compared to 4% of idiopathic cases. Positive peritoneal fluid culture, surgery, increased lactate and high packed cell volume were associated with death.