Recurrent colic in the horse: incidence and risk factors for recurrence in the general practice population.

Reasons for performing study: The frequency of recurrent colic in the UK equine general practice population is previously unreported. Elucidating risk factors for recurrent colic could provide a basis for clinical decision making and interventions.

Objectives: To determine the incidence rate of and risk factors for recurrent colic.

Hypotheses: Horse management, prophylactic health care and innate behaviour contribute to the risk of recurrent colic.

Methods: A cohort of 127 horses was enrolled at the point of a veterinary-diagnosed medical colic episode. Participating owners completed a baseline and 3 follow-up telephone questionnaires over one year. Clinical details of each colic episode were collected with data on management, behaviour and preventive healthcare. Incidence was calculated using time at risk data; non-time varying covariates were assessed for association with recurrent colic using multivariable logistic regression.

Results: The recurrence rate was 50 colic events/100 horse years at risk (HYAR). Including only veterinary attended recurrent colic episodes the incidence was 35 colic events per 100 HYAR. A multivariable logistic regression model was built to explore non-time varying risk factors for recurrence collected from baseline data. The model showed that horses that have a known dental problem (OR 5.5, 95% CI 1.3, 23.1) or crib-bite/windsuck (OR 12.1, 95% CI 1.4, 108.1) were at increased risk of recurrence during the year following a colic event.

Conclusions and potential relevance: The incidence of recurrence in horses following a medical episode of colic is high in this population and represents a welfare concern. The incidence rate can be used to compare intervention efficacy in similar populations. Identified risk factors could provide the basis for management interventions or highlight at risk individuals.