Sessions

Left (LDD) and right (RDD) dorsal displacement of the large colon are common, generally good-prognosis forms of colic in horses, yet the choice of treatment (conservative or surgical) still poses a decision-making challenge. The aim of this retrospective study was to analyse and compare the occurrence, diagnostic features, and treatment outcomes of LDD and RDD cases managed at the Department and Clinic of Equine Medicine, University of Veterinary Medicine Budapest, between 2024 and 2026. Of the 440 horses admitted with colic during the study period, 84 cases met the inclusion criteria; the data were analysed using descriptive statistics, chi-square/Fisher's exact tests, the Mann–Whitney U test, and binary logistic regression. For this purpose, the jamovi software (version 2.7) was used, built on the R statistical programming language (version 4.5). Ultrasonography confirmed left dorsal displacements of the large colon significantly more reliably than right dorsal displacements (82.9% vs. 30.0%; p<0.001), whereas rectal examination showed consistently high diagnostic accuracy (>94%) for both types. Symptom severity strongly determined the choice of treatment: mild cases were predominantly managed conservatively (92.6%), while severe cases were predominantly treated surgically (66.7%; p<0.001), and surgically treated horses also had a significantly longer hospital stay than conservatively treated ones (median 9.0 vs. 3.5 days; p<0.001). Based on univariate logistic regression, peritoneal fluid lactate level proved to be a significant prognostic factor for survival (OR=0.40; p=0.035). Conservative treatment was used more often to resolve left dorsal displacement (72.5%) than right dorsal displacement (60%). Of the conservatively treated horses, 94.5% survived, compared with only 72% of the surgically treated ones. This may be related to the fact that horses in a worse clinical condition were the ones that underwent surgery in the first place. Our results confirm that a more severe clinical presentation and the resulting need for surgical intervention are themselves associated with a poorer outcome, which underlines the importance of early recognition and an appropriate treatment decision when LDD or RDD is suspected.