Indicators of 'critical' outcomes in 941 horses seen 'out-of-hours' for colic.

Bowden, Adelle; England, Gary C W; Brennan, Marnie Louise; Mair, Tim S; Furness, Wendy A; Freeman, Sarah L; Burford, John H

BACKGROUND This study aimed to describe the presentation and outcomes of horses with signs of colic (abdominal pain) seen 'out-of-hours' in equine practice. METHODS This was a retrospective study of horses seen 'out-of-hours' with colic by two equine veterinary practices between 2011 and 2013. Case outcomes were categorised as 'critical' or 'not critical'. A critical outcome was defined as requiring medical or surgical hospital treatment, or resulting in euthanasia or death. A non-critical outcome was defined as resolving with simple medical treatment. A hierarchical generalised linear model was used to identify 'red flag' parameters (aspects of signalment, history and presenting clinical signs) associated with critical outcomes. RESULTS Data were retrieved from 941 cases that presented with colic; 23.9 per cent (n=225/941) were critical. Variables significantly associated with the likelihood of a critical outcome in the final multivariable model were increased heart rate (P<0.001), age of the horse (P=0.013) and abnormal mucous membrane colour (P<0.001). Overall 18 per cent (n=168/941) of cases were euthanased. CONCLUSIONS This study highlights the mortality associated with colic. The 'red flag' parameters identified should be considered an essential component of the primary assessment of horses with colic.