Comparison of Histopathologic Findings in Biopsies from the Duodenum and Ileum of Dogs with Enteropathy

Background In the investigations of dogs with chronic small intestinal diarrhea collection of ileal biopsies lengthens procedural time and has been of uncertain value. Objectives To evaluate whether there was agreement between histologic changes present in samples of duodenal and ileal mucosa, and hence to provide initial information in the process of determining whether collection of ileal biopsies is clinically justified. Animals 40 dogs with chronic small and large intestinal diarrhea from which endoscopic (in 30 cases) or surgical (in 10 cases) duodenal and ileal biopsies had been collected. Methods Samples were reviewed concurrently by two observers (MJD and MDW) using the scoring system developed by the World Small Animal Veterinary Association (WSAVA) Gastrointestinal Standardization Group. Comparisons were made by kappa analysis. Results Microscopic pathology was observed in 30 cases. Only eight out of this 30 (27%) had the same histopathologic diagnosis in both the duodenum and the ileum. This dropped to 3 out of 30 (10%) if different disease severity was also considered as disagreement. Microscopic pathology would have been found in 60% and 80% of the 30 cases, if only duodenal or ileal biopsies respectively, had been available. Conclusions and clinical importance There was poor agreement between histopathological findings from duodenal versus ileal biopsies with abnormalities sometimes being more readily detected in the ileum. Routine collection of ileal plus duodenal samples appears warranted when concurrent small and large intestinal diarrhea is present.