Surgical treatment of equine colic - a retrospective study of 297 surgeries in Norway 2005–2011

BACKGROUND Colic, defined as pain originating from the abdomen, is a common condition in horses. Most of the cases resolve spontaneously or after medical treatment, but a few require surgical treatment. Surgical treatment of colic in horses is resource-demanding and expensive, and information on prognosis is therefore important for both owners and surgeons. In the present study, surgical cases in two equine hospitals in Norway between 2005 and 2011 were reviewed. The aim of the study was to describe associations between prognostic indicators, diagnoses and short term survival by use of random effects logistic regression. RESULTS In the present study, 162 out of 297 (54.5%) surgeries resulted in the horse being discharged from the hospital. Excluding cases euthanized during surgery, the overall short-term survival was 74.0% (162 out of 219 surgeries). Seventy-eight (26.3%) of the horses were euthanized during surgery, due to grave or poor prognosis. In univariable analyses, duration of colic signs, heart rate, capillary refill time, mucosal membrane appearance, intestinal sounds, affected gastrointestinal segment, hematocrit, intestinal resection, hospital and surgeon board-certification had P-value <0.20 and were assessed in multivariable analyses. Respiration rate, rectal temperature and lactate in blood also had univariable P <0.20, but were left out from multivariable analyses due to too high levels of missing values. A random effect of primary surgeon was included and breed, sex and age were tested in multivariable analyses as possible confounders; and hospital was included to control for hospital routine differences. In the final multivariable model the variables mucosal membrane appearance, affected gastrointestinal segment and surgeon board-certification significantly influenced survival. The random surgeon effect was not significant. CONCLUSIONS The present study showed that prognostic parameters and diagnoses of surgical treatment of horses with colic in Norway are in accordance with reports from other parts of the world. The significant effect of board-certification of surgeon is not reported in previous studies. The general short-term survival rate was somewhat lower than reported in other studies, partly due to more horses being euthanized intraoperatively in the present study. This might be because of economical or animal welfare reasons.