Abstract: Background: The etiology of hyperemic equine glandular gastric disease (EGGD) remains poorly characterized. In people, reflux of bile into the stomach can cause bile gastropathy and has many parallels to hyperemic EGGD.
Hypothesis/Objectives: We hypothesize that there is an increase in bile acid concentrations with an increased proportion of conjugated bile acids in the pyloric gastric fluid associated with hyperemic EGGD. Our specific objective is to compare the bile acid profiles of pyloric gastric fluid between horses with and without hyperemic EGGD.
Animals: Horses from the institutional herd underwent gastroscopic evaluation. Enrolled horses were designated as control (no abnormalities observed, n=8) or affected (hyperemic EGGD observed, n=15). Of the 15 horses with hyperemic EGGD, lesions (disruption of the mucosal surface) were also observed in seven.
Methods: This was a case-control study in horses with naturally occurring EGGD. During gastroscopic evaluation, gastric fluid was collected from the pylorus. Bile acid concentrations were measured using custom ultra-performance liquid chromatography coupled with mass spectrometry (UPLC/MS). Concentrations were compared between groups using a t-test or Mann-Whitney U test.
Results: Thirteen bile acids were analyzed: ten had measurable concentrations in all horses (n=23), two in 22 horses, and one in only 3 horses. Affected horses had increased concentrations of taurolithocholic acid (p=0.044), lithocholic acid (p=0.023), and hyodeoxycholic acid (p=0.002) compared to controls. There was no difference detected in the percentage of conjugated or unconjugated bile acids between groups.
Conclusions and clinical importance: These results support a role of bile acid reflux in pyloric, hyperemic EGGD.
Learning Objectives:
Introduce the concept of bile acid reflux as an etiology of hyperemic equine glandular gastric disease.
