Small Colon Faecalith with Large Colon Displacement in Ten Cases (2015–2023): A Detailed Case Description and Literature Review

Simple Summary Impactions are the most common issue affecting the small colon in horses, particularly in miniature horses and ponies. Risk factors for small colon faecalith include poor dentition, reduced water consumption, parasite damage, or poor-quality hay. Abdominal pain can range from mild to severe due to intraluminal gas distention orally to the impaction site. Previously, large colon tympany has been identified as a predisposing factor for large colon displacement or volvulus. The aim of this study was to describe the history, clinical and surgical features, and outcome in 10 cases which underwent exploratory laparotomy, where a diagnosis of small colon faecalith concomitant with large colon volvulus or right dorsal displacement was reached. In all clinical cases, the small colon faecalith was determined to be the primary lesion during celiotomy, underscoring the importance of a thorough examination of the small colon tract when diagnosing large colon displacement or volvulus during exploratory laparotomy.Abstract Small colon impaction can result in accumulation of ingesta, gas, and fluid orally to the impaction site in horses. Large colon tympany, which is caused by ingesta fermentation, can be a predisposing factor for intestinal displacement. The aim of this study is to report the history, clinical, and surgical findings of horses and ponies referred for abdominal pain not responsive to drugs where a right dorsal displacement (RDD) or large colon volvulus (LCV), together with a small colon faecalith (SCF), were diagnosed during surgery. This study included a total of five horses and five ponies. Based on clinical features, ultrasonographic examination, and rectal palpation, an initial suspected diagnosis of RDD, LCV or severe large colon and caecum distension was made in all clinical cases. Due to the lack of response to medical treatment or worsening of colic symptoms, surgery was performed in all horses: diagnosis of RDD or LCV was made and a SCF was incidentally detected in all cases. While exploratory laparotomy was carried out in all the patients for the presence of a large colon issue, it was probably subsequent to an obstruction of the small colon caused by the presence of an SCF, which is generally difficult to diagnose. This study reported the presence of SCF as a possible cause of secondary RDD or LCV in horses and ponies that, to the authors' knowledge, has never been reported.