Abstract
REASONS FOR PERFORMING STUDY: There is limited information about risk factors and survival associated with disorders of the small colon requiring surgical management. OBJECTIVES: 1) To document the types of surgical lesion in horses where pathology of the small (descending) colon was the primary cause of abdominal pain, 2) to describe the short- and long-term survival of these cases and identify factors associated with survival and 3) to identify preoperative variables associated with localisation of a lesion to the small colon. METHODS: Clinical data and long-term follow-up were obtained for horses that underwent exploratory laparotomy over a 10-year period. Descriptive data were generated for short- and long-term survival and survival analysis performed to identify factors associated with reduced survival. Univariable and multivariable relationships were explored using a Cox proportional hazards model. Preoperative factors associated with increased likelihood of a small colon lesion were explored, using controls randomly selected from horses undergoing exploratory laparotomy for treatment of colic unrelated to the small colon. RESULTS: The study population included 84 horses. Of horses with small colon lesions recovered from anaesthesia, the percentage that survived until discharge, one year and 2 years following surgery, was 91.0, 81.0 and 73.5%, respectively. Median survival time for horses in which a resection had been performed was 1029 vs. 3072 days in the nonresection group. Small colon cases were more likely to have shown a longer duration of colic signs prior to admission (P<0.001) and to develop post operative diarrhoea (P = 0.001) when compared with surgical controls. CONCLUSIONS: Lesions of the small colon carry a good prognosis for survival following surgery. Resection and anastomosis was the only factor associated with reduced long-term survival. POTENTIAL RELEVANCE: This study provides information about lesion types and post operative survival that may be used to assist informed decision-making when managing these cases.