Survival and complication rates in 300 horses undergoing surgical treatment of colic. Part 1: Short-term survival following a single laparotomy

Reasons for performing study: A minority of equine colic cases prove fatal unless treated surgically; however, few studies have considered long-term survival and complication rates, and few have attempted to identify factors that might affect outcomes. Such information is required for owners and veterinary surgeons to make informed decisions about the most appropriate treatment for individual cases. Objectives: To document short-term survival rates of 300 horses undergoing colic surgery and analyse factors that might have predisposed to short-term death. Methods: History, clinical and surgical findings, treatments and outcomes of 300 surgical colic cases (1994-2001) were reviewed. Comparisons among groups of discrete data were made using chi-squared or Student's t tests as appropriate. Significance was set at P < 0.05, and 95% confidence intervals were calculated for percentages. Results: The short-term survival rate (to discharge) was 70.3% for all horses and 83.1% for those recovering from anaesthesia; for horses that had a single laparotomy it was 87.2%. The most common reasons for death/euthanasia in the post operative period after a single laparotomy were persistent pain/colic, post operative illeus and grass sickness. Horses with lesions involving the small intestine and caecum had lower survival rates (75.2 and 66.7%, respectively) than those with large colon or small colon lesions (89.9 and 100%, respectively). The survival rate for ischaemic/strangulating lesions (68.9%) was lower than for simple obstructions (90.5%). Conclusions: Short-term survival of horses undergoing exploratory laparotomy for acute colic is dependent on many factors, including the nature of the underlying disease, cardiovascular status and post operative complications. Potential relevance: These retrospective studies may be used as a basis for prospective studies assessing treatments that could ultimately improve survival and decrease complication rates.