Comparison of Histopathological Findings in Endoscopic Biopsies from the Duodenum and Ileum of Dogs with Enteropathy
D. Casamian Sorrosal1; M. Willard2; J. Murray1; E.J. Hall1; M.J. Day1
Introduction
Endoscopic duodenal biopsy is the most widely used means of obtaining samples for histopathological diagnosis in dogs with chronic small intestinal diarrhoea. Collection of ileal biopsies via colonoscopy is usually only performed when large intestinal diarrhoea is also present. The aim of this retrospective study was to evaluate whether there was agreement between histological changes at these two anatomical sites, and to therefore determine whether the collection of ileal biopsies was clinically justified.
Materials and Methods
The records of dogs that underwent endoscopic intestinal biopsy at the University of Bristol (January 2002-June 2007) were reviewed. Of these, only 24 cases had both duodenal and ileal biopsies of adequate quality. The mean number of biopsies collected from each dog was 7.35 (duodenum) and 5.53 (ileum). These samples were reviewed jointly by two observers (MJD and MW) on a single occasion using the scoring system developed by the WSAVA Gastrointestinal Standardization Group. Comparisons between duodenal and ileal findings were made by Kappa analysis.
Results
Thirty-three percent (8/24) of cases had the same histological diagnosis in both regions. However, in six of these cases no abnormalities were detected in either region, so only two cases with microscopical changes had agreement. By contrast, in 16/24 cases (67%) there was no agreement (Kappa <0.00) between the histological diagnoses made with the biopsies collected from the two anatomical sites. Comparison of the severity of changes with a similar diagnosis in both sites was not possible due to insufficient cases (n=2) but within these two cases there was lack of agreement. A histopathological diagnosis would have been made in 27.8% (5/18) and 72.2 % (13/18) of the cases with microscopical changes if only duodenal or ileal biopsies respectively had been available.
Conclusion
This study indicates that there is poor overall agreement between histopathological findings derived from duodenal and ileal endoscopic biopsies collected from the same animal. Moreover, histopathological abnormalities appear to be more readily detected in the ileal compared with the duodenal mucosa. In light of these results, routine collection of ileal biopsies appears warranted in dogs with small intestinal diarrhoea.