The usability of peritoneal lactate concentration as a prognostic marker in horses with severe colic admitted to a veterinary teaching hospital.

Colic can be a life-threatening condition in horses and there is a need for parameters that can help determine the prognosis and need for surgery. The aim of the study was to investigate whether peritoneal fluid (PF) lactate concentration is useful for this purpose in horses with severe colic presented to a veterinary hospital. During a 16 month period, the peritoneal fluid (PF) lactate concentration was measured in 74 of 760 colic horses admitted to the Utrecht University equine clinic using a portable analyser. When comparing survivors and nonsurvivors, heart rate, PF and blood lactate concentrations and blood glucose concentration were significantly higher in horses that did not survive. No horse with a PF lactate concentration >9.4 mmol/l survived. The presence of a strangulating lesion was also significantly associated with nonsurvival, as was PF colour: no horse with red PF survived in the present series. In horses with yellow PF, the blood glucose concentration was correlated with the presence of a strangulating intestinal lesion. Peritoneal lactate concentrations can be easily and rapidly measured using a portable analyser and may be useful in assessing the prognosis and/or need for surgery in equine colic cases.