Duration of disease influences survival to discharge of Thoroughbred mares with surgically treated large colon volvulus.
Authors: Hackett E S, Embertson R M, Hopper S A, Woodie J B, Ruggles A J
Journal: Equine veterinary journal
Summary
Large colon volvulus demands urgent surgical intervention, yet the critical window between symptom onset and treatment remains poorly quantified in terms of its prognostic significance. This retrospective analysis examined 896 Thoroughbred mares (1039 surgical procedures) treated between 1986 and 2011, using multivariable logistic regression to determine which perioperative factors predicted survival to discharge. Pre-admission colic duration emerged as a statistically significant predictor of outcome alongside seven other variables including packed cell volume, surgical duration, intraoperative hypotension, post-operative heart rate, faecal consistency, and hospitalisation length—with the cohort achieving an 88% overall survival rate. The data substantiate what practitioners intuitively recognise: faster referral and shorter time to anaesthetic induction correlate with improved survival, likely reflecting reduced ischaemic damage to the colon and systemic compromise from prolonged strangulation obstruction. For equine professionals managing colic cases, these findings reinforce that aggressive early intervention and rapid transport to a surgical facility remain the most modifiable factors influencing prognosis in suspected large colon volvulus, whilst post-operative monitoring of heart rate and gastrointestinal function provides additional prognostic information about tissue viability and recovery trajectory.
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Practical Takeaways
- •Early referral and prompt surgical treatment are critical—each hour of delay before admission reduces survival chances in mares with large colon volvulus
- •Monitor packed cell volume, intra-operative blood pressure stability, and post-operative heart rate and digestive function as indicators of prognosis and complications
- •Communicate to owners that mares with large colon volvulus have good overall prognosis (88% survival) when treated surgically, but outcomes depend heavily on time from onset of colic to surgery
Key Findings
- •Overall survival to discharge was 88% in Thoroughbred mares treated surgically for large colon volvulus
- •Duration of colic signs prior to admission was statistically significantly associated with survival outcomes
- •Median duration of colic signs before admission was 2 hours (IQR 1-4 hours), with median time from admission to anaesthetic induction of 25 minutes
- •Risk factors for reduced survival included longer colic duration, elevated packed cell volume at admission, longer surgical time, hypotension during anaesthesia, elevated heart rate 48 hours post-operatively, and abnormal post-operative manure consistency