Colic in competing endurance horses presenting to referral centres: 36 cases

Summary Reasons for performing study: Colic is a common reason for elimination from equine endurance competitions and has recently been identified as the leading cause of mortality in this group of horses. Hydration and electrolyte derangements are often severe, but are probably related to endurance exercise and not necessarily the episode of colic. Better understanding of the causes of colic and the expected outcome is needed to guide treatment decisions in endurance horses. Objectives: To describe the history, case details, clinical examination, laboratory, treatment and outcomes for horses presenting to equine referral centres for treatment of colic associated with endurance competition and to identify variables associated with prolonged hospitalisation. Methods: Thirty-six horses from 2 equine referral centres were included in the analysis. In addition to descriptive statistics, Cox proportional hazards models were used to evaluate factors associated with length of hospitalisation. Results: A diagnosis of open or ileus was made in the majority of horses (56%). Salmonellosis and enteritis (Salmonella negative) were also recognised (16%). Exploratory abdominal surgery was performed in 5 of the horses. Only one of 36 horses did not survive to discharge. Previous eliminations from competition (negative association) and total i.v. fluids within the first 24 h (positive association) of admission were both associated with length of hospitalisation. Conclusions: Endurance horses with colic typically respond to medical treatment but in some cases hospitalisation may be prolonged. The role of Salmonella infections in endurance horses with colic requires further research. Potential relevance: Despite potentially severe clinical and laboratory derangements, equine practitioners should make owners aware that the prognosis for competing endurance horses with colic is good when treated appropriately.