Pathophysiology of Gastric Ulcer Disease
Authors: Murray Michael J.
Journal: The Equine Acute Abdomen
Summary
# Editorial Summary: Pathophysiology of Gastric Ulcer Disease Michael J. Murray's investigation into equine gastric ulceration examined how feeding patterns influence the chemical environment within the stomach, and crucially, how this environment damages the protective mucosal layer. Using nasogastric sampling and in vitro tissue models, Murray demonstrated that fasting rapidly elevates bile salt concentrations to potentially damaging levels (0.23–0.44 mmol/l after 14 hours without feed), whilst feeding keeps these concentrations safely below 0.2 mmol/l; gastric pH alone showed no significant variation between feeding protocols. The critical finding emerged from laboratory testing of isolated gastric mucosa: whilst acid or bile salts independently caused minimal injury, their combination produced sustained, irreversible damage to the tissue's electrolyte transport function—a mechanism that explains why fasted horses are particularly vulnerable to ulceration. These results provide mechanistic evidence supporting increased feeding frequency and extended forage availability as preventative strategies, particularly for horses in high-stress situations (competition, training, hospitalisation) where extended fasting periods cannot be avoided; the 14-hour threshold is particularly relevant for overnight management protocols.
Read the full abstract on PubMed
Practical Takeaways
- •Extended fasting periods (≥14 hours) create conditions that damage gastric mucosa through bile salt and acid synergy; frequent feeding protocols may help prevent ulcer development
- •Feeding hay alone is insufficient protection—the combination of gastric acid and bile salts is what causes mucosal injury, explaining why grazing/frequent feeding is protective
- •Horses subjected to long transport, competition schedules, or stabling without frequent feed access are at elevated risk for gastric ulceration due to predictable changes in gastric chemistry
Key Findings
- •Bile salt concentrations were significantly higher in fasted horses (0.23-0.44 mmol/l) compared to fed horses (<0.2 mmol/l)
- •Acid alone caused reversible decreases in mucosal electrical potential difference that recovered within 20 minutes
- •Combined exposure to bile salts and acid caused irreversible decreases in electrical potential difference across stratified squamous mucosa
- •Pathogenic concentrations of bile salts and acid sufficient to alter mucosal electrolyte transport can develop within 14 hours of feed deprivation