Research Updates: Should biopsy samples be routinely collected from the duodenum and ileum in dogs with clinical signs suggestive of concurrent small and large bowel diarrhea? - Veterinary Medicine
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Research Updates: Should biopsy samples be routinely collected from the duodenum and ileum in dogs with clinical signs suggestive of concurrent small and large bowel diarrhea?



Based on these results, the authors concluded that collecting biopsy samples from the ileum does, in fact, appear warranted in dogs with clinical signs of both large and small bowel diarrhea. Obtaining biopsy samples from the most distal small intestinal segment would indeed have altered the final diagnosis in most dogs. When severity was considered as well, only one in 10 dogs would have had an unchanged diagnosis after examination of the ileal biopsy sample.

Unfortunately, most colonic biopsy samples obtained from the study dogs did not reveal any histopathologic lesions, emphasizing that ileal samples are required when examining the distal gastrointestinal tract. The authors note that in some cases, lesions were in fact identified in the ileum whereas the duodenum was histologically unremarkable, which may be because the distal intestine's thinner mucosa allows easier collection of adequate samples by most endoscopists. Alternatively, in some dogs, the ileum may be the location of earliest disease changes, in which case ileal biopsies would be required if diffuse disease did not yet involve the entire intestine.

Unfortunately, the authors did not report folate or cobalamin concentrations in this report, which would have provided indirect evidence about the extent of small intestinal disease in these dogs. Correlating the presence and degree of hypocobalaminemia with ileal histopathologic changes could prove to be a useful indicator as to the need to obtain biopsy samples from the ileum.

The primary limitations of this study are the failure to include dogs with intestinal lymphoma and the relatively high percentage of dogs with eosinophilic gastroenteritis. Because most published studies on idiopathic gastroenteritis (i.e. inflammatory bowel disease) have demonstrated that lymphocytic-plasmacytic enteritis is the most common histologic subtype encountered, the population included here raises concern for unintentional study bias. Additionally, although this study suggests that type and severity of inflammation may differ depending on which anatomic site is sampled in dogs with diffuse bowel clinical signs, the utility of obtaining ileal biopsies in patients with only small bowel diarrhea is still unknown.

Casamian-Sorrosal D, Willard MD, Murray JK, et al. Comparison of histopathologic findings in biopsies from the duodenum and ileum of dogs with enteropathy. J Vet Intern Med 2010;24(1):80-83.

The information in "Research Updates" was provided by Erika Meler, DVM, MS, and Barrak Pressler, DVM, PhD, DACVIM, Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Purdue University, West Lafayette, IN 47907.


1. Willard MD, Mansell J, Fosgate GT, et al. Effect of sample quality on the sensitivity of endoscopic biopsy for detecting gastric and duodenal lesions in dogs and cats. J Vet Intern Med 2008;22(5):1084-1089.

2. Willard MD, Moore GE, Denton BD, et al. Effect of tissue processing on assessment of endoscopic intestinal biopsies in dogs and cats. J Vet Intern Med 2010;24(1):84-89.

3. Kleinschmidt S, Meneses F, Nolte I, et al. Retrospective study on the diagnostic value of full-thickness biopsies from the stomach and intestines in dogs with chronic gastrointestinal disease symptoms. Vet Pathol 2006;43(6):1000-1003.


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