Influence of Salmonella status on the long-term outcome of horses after colic surgery.
Authors: Southwood Louise L, Lindborg Susan, Myers Marc, Aceto Helen W
Journal: Veterinary surgery : VS
Summary
# Influence of Salmonella status on long-term outcome of horses after colic surgery Horses discharged following colic surgery represent a significant investment, but uncertainty remains about whether Salmonella colonisation affects their long-term prognosis and usefulness. This retrospective study compared 59 Salmonella-positive horses with 119 matched Salmonella-negative controls, tracking complications, survival and return to work for a minimum of 12 months post-discharge through owner interviews and multivariable statistical analysis. Salmonella-positive horses demonstrated higher odds of surgical site infection (2.7-fold increase) and weight loss (6.8-fold increase) during recovery, yet long-term survival rates were comparable between groups (95% versus 84%), with postoperative colic—not Salmonella status—emerging as the primary driver of non-survival (hazard ratio 7.6). Remarkably, approximately three-quarters of both Salmonella-positive and Salmonella-negative horses returned to their intended level of use, indicating that Salmonella carriage at discharge does not substantially compromise functional outcomes. For practitioners managing post-operative colic cases, this finding suggests that whilst Salmonella-positive status warrants heightened vigilance for wound complications and nutritional support during the immediate recovery phase, it should not significantly alter long-term prognosis or expectations for return to performance, provided horses navigate the critical post-operative period without recurrent colic.
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Practical Takeaways
- •Horses that are Salmonella-positive at discharge can have similar long-term outcomes to negative horses, so a positive culture should not automatically preclude a guarded prognosis for return to function
- •Watch carefully for postoperative colic recurrence in all post-surgical colic cases—this carries the highest risk for poor long-term survival regardless of infection status
- •Monitor for surgical site infection and weight loss in Salmonella-positive cases, as these complications occur more frequently, though most horses still return to work
Key Findings
- •Salmonella-positive horses had 2.7× higher odds of surgical site infection and 6.8× higher odds of postoperative weight loss compared to negative horses
- •Long-term survival was 95% for Salmonella-positive versus 84% for Salmonella-negative horses at >12 months follow-up
- •Postoperative colic was the strongest predictor of non-survival (hazard ratio 7.6) regardless of Salmonella status
- •76% of Salmonella-positive and 80% of Salmonella-negative horses returned to intended use, showing no significant difference