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Home / Equine Research Bank / J Vet Diagn Invest / Gastrointestinal biopsy in the horse: overview of collection...
Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc2022; 34(3); 376-388; doi: 10.1177/10406387221085584

Gastrointestinal biopsy in the horse: overview of collection, interpretation, and applications.

Abstract: Evaluation of gastrointestinal (GI) biopsies is a multistep process that includes reviewing an appropriate history, determining sample quality, and evaluating histologic sections. Selected diagnostic parameters that, in combination with intestinal histopathology, can be useful to localize disease to the intestinal tract in the horse include hypoproteinemia and hypoalbuminemia, ultrasound evidence of increased thickness of the small intestinal wall, and alterations in glucose or D-xylose absorption tests. Biopsies may be acquired either endoscopically, or via laparoscopy or standing flank incisional approaches. GI sections should be evaluated using a systematic approach that includes both architectural changes and inflammatory cell infiltrates. Although strategies have been developed for assessment of GI biopsies from the dog and cat, a standardized approach to interpretation of the equine GI biopsy has yet to be developed. GI biopsies pose several challenges to the pathologist, especially for endoscopic biopsies in which the quality of the specimen and its orientation may vary greatly. Architectural changes are arguably the most critical changes to evaluate. In a horse with chronic GI inflammation, such as occurs in idiopathic inflammatory bowel disease (IBD), the cell types encountered frequently are macrophages, eosinophils, lymphocytes, and plasma cells. Increased numbers of these cell types are categorized loosely as mild, moderate, and severe. Specific forms of idiopathic IBD have been further classified by this infiltrate as granulomatous enteritis, eosinophilic enteritis, and lymphoplasmacytic enteritis; there is limited information on microscopic changes with each. Unfortunately, microscopic GI lesions are usually nonspecific, and determination of etiology requires further investigation.
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Publication Date: 2022-03-31 PubMed ID: 35354416PubMed Central: PMC9254066DOI: 10.1177/10406387221085584Google Scholar: Lookup
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Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

The study is about the process of evaluating gastrointestinal biopsies in horses. It discusses the steps involved, the parameters of diagnostic value, different collection methods used, and the interpretation of results. The study highlights the challenges faced, especially in interpreting endoscopic biopsies and emphasizes the need for a standardized approach.

Process of Evaluating GI Biopsies

  • The assessment of gastrointestinal biopsies is a layered process that starts with an analysis of the horse’s medical history, evaluating the quality of the biopsy sample and reviewing histologic sections.
  • Parameters such as hypoproteinemia and hypoalbuminemia, increased thickness of the small intestinal wall observed through ultrasound, and changes in glucose or D-xylose absorption tests can help pinpoint the disease to the intestinal track.

Collection Methods

  • Biopsy samples may be collected using endoscopic methods or through laparoscopic or standing flank incisional approaches.
  • The choice of method can greatly impact the quality and orientation of the specimen.

Interpretation of Biopsy Results

  • Interpretation of the gastrointestinal biopsies should be done systematically, evaluating both the architectural modifications and the infiltration of inflammatory cells.
  • In horses with chronic gastrointestinal inflammation, such as idiopathic inflammatory bowel disease (IBD), the presence of increased numbers of certain cell types such as macrophages, eosinophils, lymphocytes, and plasma cells is a common finding.
  • These inflammation levels are generally classified as mild, moderate, and severe depending on the degree of cellular infiltration.

Challenges

  • Despite developed strategies for assessing GI biopsies in dogs and cats, a standardized approach for horses is still lacking.
  • Interpretation is particularly challenging for endoscopic biopsies, due to variable sample quality and orientation.
  • Microscopic changes in the GI are usually not specific, making it difficult to determine the cause of these changes without further investigation.

Cite This Article

APA
Hostetter JM, Uzal FA. (2022). Gastrointestinal biopsy in the horse: overview of collection, interpretation, and applications. J Vet Diagn Invest, 34(3), 376-388. https://doi.org/10.1177/10406387221085584

Publication

Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc
ISSN: 1943-4936
NlmUniqueID: 9011490
Country: United States
Language: English
Volume: 34
Issue: 3
Pages: 376-388

Researcher Affiliations

Hostetter, Jesse M
  • Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.
Uzal, Francisco A
  • California Animal Health and Food Safety Laboratory System, University of California-Davis, San Bernardino, CA, USA.

MeSH Terms

  • Animals
  • Biopsy / veterinary
  • Cat Diseases / pathology
  • Cats
  • Dog Diseases
  • Dogs
  • Enteritis / veterinary
  • Horse Diseases / pathology
  • Horses
  • Inflammatory Bowel Diseases / diagnosis
  • Inflammatory Bowel Diseases / pathology
  • Inflammatory Bowel Diseases / veterinary

Conflict of Interest Statement

Declaration of conflicting interests: The authors declared no potential conflicts of interest with respect to research,authorship, and/or publication of this article.

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Citations

This article has been cited 4 times.
  1. Tharwat M, Al-Sobayil F. Equine colic: A comprehensive overview of the sonographic evaluation, diagnostic criteria, and management of different categories. Open Vet J 2025 Mar;15(3):1116-1139.
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  2. Verhaar N, Hammer E, Reineking W, Hewicker-Trautwein M, Geburek F. Ex vivo comparison of full-thickness biopsy techniques in the equine small intestine. Vet Surg 2025 Jan;54(1):208-218.
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  3. Bardell D, Rocchigiani G, Ressel L, Milner P. Histological Evaluation of Resected Tissue as a Predictor of Survival in Horses with Strangulating Small Intestinal Disease. Animals (Basel) 2023 Aug 26;13(17).
    doi: 10.3390/ani13172715pubmed: 37684979google scholar: lookup
  4. Onzere CK, Hulbert M, Sears KP, Williams LBA, Fry LM. Tulathromycin and Diclazuril Lack Efficacy against Theileria haneyi, but Tulathromycin Is Not Associated with Adverse Clinical Effects in Six Treated Adult Horses. Pathogens 2023 Mar 14;12(3).
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