Survival of horses following strangulating large colon volvulus

The pattern of long-term survival and specific factors associated with long-term survival have not previously been evaluated in horses with a strangulating large colon volvulus (LCV).

To provide data on the long-term survival of horses with LCV and to identify pre-, intra- and post operative variables associated with survival.

Clinical data and long-term follow-up information were obtained from 116 horses with a strangulating LCV (≥360°) undergoing general anaesthesia. Two multivariable Cox proportional hazards models for post operative survival time were developed: Model 1 included all horses and evaluated preoperative variables and Model 2 included horses that survived anaesthesia and evaluated pre-, intra- and post operative variables.

The study population comprised 116 horses. Eighty-nine (76.7%) survived general anaesthesia. Of these, the percentage that survived until discharge, to one year and to 2 years was 70.7%, 48.3% and 33.7%, respectively. Median survival time for horses that survived general anaesthesia was 365 days. In Model 1 increased preoperative packed cell volume (PCV) was significantly associated with reduced post operative survival (hazard ratio [HR] 1.08, 95% confidence interval [CI] 1.05-1.11). However, this effect changed over time. In Model 2 abnormal serosal colour intraoperatively (HR 3.61, 95% CI 1.55-8.44), increased heart rate at 48 h post surgery (HR 1.04, 95% CI 1.02-1.06), and colic during post operative hospitalisation (HR 2.63, 95% CI 1.00-6.95), were all significantly associated with reduced post operative survival.

Survival time in horses with a LCV was associated with preoperative PCV, serosal colour, heart rate at 48 h post operatively and colic during post operative hospitalisation.

This study provides evidence-based information on the long-term survival of horses with LCV and identifies parameters that may assist decision-making by clinicians and owners.