[Comparison of the findings of rectal examination and ultrasonographic findings in horses with colic].

Objective: The examination of patients suffering from an acute abdomen routinely comprises both clinical and rectal examinations, and is ever more frequently accompanied by an ultrasonographic abdominal examination. The aim of the study was to compare the findings as defined through rectal examination with the results of the ultrasonographic examination for different forms of colic.
Material and Methods: In a retrospective study, the patient records of the Large Animal Clinic of the University of Leipzig from 2012 and 2013 were analysed, and those of horses suffering from colic were included. Diagnoses made through rectal and ultrasonographic examination were grouped and compared with the diagnoses made during colic surgery or pathologic examination, which served as the gold standard. Horses that underwent conservative treatment had a definitive diagnosis assigned only in cases where a pathognostic rectal finding defined the diagnosis. Based on these data, sensitivity, specificity and positive and negative predictive values were calculated for both techniques.
Results: Ultrasonography was more sensitive than rectal examination in cases of small intestinal occlusion (97.1% vs. 50.7%), torsion of the large colon in the long axis (63.2% vs. 26.3%) and dislocation of the large colon into the nephrosplenic space (90.9% vs. 72.7%). Rectal examination was more sensitive than ultrasonographic examination in cases of other types of dislocation of the large colon (96.5% vs. 8.8%) and of constipations of the large colon (93.6% vs. 29.8%).
Conclusion and Clinical Relevance: In cases of severe diseases, including small intestinal occlusions and torsions of the large colon, ultrasonography helps to better identify and more precisely diagnose conditions that in most cases require abdominal surgery than rectal examination. Therefore, under hospital conditions, it is highly advisable to include ultrasonography in the routine examination of the equine acute abdomen. However, this technique does not replace the traditional rectal examination, which is superior in the diagnosis of dislocations and constipations of the large colon as well as diseases of the caecum.