Activity of 1,2-o-dilauryl-rac-glycero-3-glutaric acid-(6'-methylresorufin) ester lipase in peritoneal fluid may be associated with strangulating lesions, pancreatic fibrosis, and negative outcome in horses with colic.

Objective: To compare plasma and peritoneal 1,2-o-dilauryl-rac-glycero-3-glutaric acid-(6'-methylresorufin) ester (DGGR) lipase activity between horses with and without colic signs and document pancreatic histopathology in a subset of horses. Methods: This prospective, cross-sectional study included university-owned or donated healthy horses and client-owned horses presenting to the veterinary teaching hospital for colic. Peritoneal WBC and lactate concentrations and plasma and peritoneal DGGR lipase activity were measured. Pancreatic tissue was collected via convenience sampling. Pancreatic fibrosis and autolysis were defined with the use of a histopathologic grading scheme. Lipase activity was compared between groups, and these findings were related to WBC counts, lactate concentrations, and pancreatic histopathology. Results: Samples were collected from 25 healthy and 30 colic horses, and pancreatic tissue was collected from 5 healthy and 7 colic horses. Plasma and peritoneal lipase activity was significantly correlated in colic horses and higher compared to healthy horses. Significant correlations were shown between peritoneal lactate and WBC concentrations with plasma and peritoneal DGGR lipase activity. Peritoneal DGGR lipase activity was associated with strangulating lesions and nonsurvival. Acute pancreatitis was identified grossly in 1 colic horse. Pancreatic fibrosis and autolysis were identified in 1 healthy and 7 colic horses. Correlations between fibrosis and lipase activity were detected. Conclusions: Hyperlipasemia and pancreatic fibrosis were common among colic horses and may be associated. Peritoneal lipase activity may be associated with strangulating lesions and outcome. Clinical Relevance: The results of this study suggest that pancreatitis may occur with colic. Further investigation of the clinical implications of these results is warranted.