Pathologic changes associated with induced small intestinal strangulation obstruction and nonstrangulating infarction in horses.

Arteriovenous (ischemic strangulation obstruction, ISO) or venous (hemorrhagic strangulation obstruction, HSO) occlusions were created in the jejunum of 5 anesthetized horses and were left in situ for 1-, 2-, or 3-hour intervals. Segments were evaluated grossly for color, thickness, and motility. The horses were euthanatized, and the degree of mucosal slough, edema, congestion, and hemorrhage was determined histologically. Segments subjected to ISO became dark, but did not contain edema or hemorrhage. Segments subjected to HSO were characterized by progressive congestion, edema, and hemorrhage especially in the mucosal layer. Histologically, the mucosal epithelium was affected approximately equally by ISO or HSO, although more gross changes were evident in segments subjected to HSO.