Professor University of Montreal St-Hyacinthe, Quebec, Canada
Abstract: Background - Endoscopic digestive biopsies are commonly taken in horses with a typical clinical context of weight loss, malabsorption, hypoproteinemia and/or recurrent abdominal pain. Hypothesis/Objective - The objectives are to describe the clinical and histological findings in horses that had endoscopic duodenal and rectal biopsies taken. Animals - This retrospective study evaluated 36 horses with digestive biopsies Methods - Retrospective clinical study includes horses with complete medical records that also had digestives biopsies taken at the VMTH (2017-2021). Results - Over the past 5 years, we observed an increasing trend of endoscopic duodenal/rectal sampling at our Equine Hospital and identified 36 horses with such biopsy samples. Ten of those horses had no significant histological changes and 26 had increased immune cell infiltrations. Duodenitis/proctitis were most often described as lymphoplasmacytic (54% and 37% from duodenal and rectal tissues respectively). The infiltration intensity ranged in most cases from minimal to mild (82%) with low correlation between duodenal and rectal changes (28%) in the same patient. Horses with increased duodenal infiltrates were also more likely to have an additional diagnosis of gastric glandular ulcers (46%), compared to horse without increased duodenal infiltrates (20%). Conclusion and clinical relevance - The clinical usefulness for endoscopic digestive biopsies in horses is likely more important than previously described in the literature and lymphoplasmacytic enteritis is the most frequent histological finding. The histological interpretation of both duodenal and rectal biopsies in equine patient provides a more complete evaluation of the infiltrating immune cells and their intensity.
