Risk factors for reduced postoperative fecal output in horses: 37 cases (1997-1998).

Abstract

To determine prevalence and risk factors for development of ileus of the large intestine after surgery in horses, identified by reduced postoperative fecal output (RPFO). Retrospective study. 37 horses that developed RPFO after undergoing general anesthesia for reasons unrelated to the gastrointestinal tract. Fecal output was obtained from medical records as number of defecations per 24-hour period after surgery; RPFO was defined as < or = 3 defecations per 24-hour period after surgery. The reference population included 48 horses that defecated > or = 4 times during the same period. Demographic, clinical, and surgical variables were evaluated for their association with development of RPFO by use of logistic regression analysis. Ten (12%) horses, all of which had RPFO, developed signs of colic after surgery. Horses > or = 5 years old that underwent orthopedic procedures of > 60 minutes' duration and that did not receive phenylbutazone after surgery were at significant risk for developing RPFO. Results suggest that after surgery unrelated to the gastrointestinal tract in horses, there is an intermediate clinical phase characterized by reduced fecal output preceding overt signs of colic. Recognition of RPFO may reduce morbidity and mortality of such horses.