Role of duodenal reflux in nonglandular gastric ulcer disease of the mature horse.

The research examines how the combination of bile salts and acid, both present in horses’ stomach contents, contribute to nonglandular gastric ulcer disease. The study found that this combination was more harmful to the gastric mucosa of horses than the acid alone, and this is most prevalent in horses that have been deprived of feed for 14 hours or longer.

Methodology

• The research adopted the method of collecting gastric contents from horses using nasogastric tubes. These samples were used to observe changes in pH and bile salt concentrations.
• Four different feeding protocols were applied to the horses: being fed with hay only, hay with twice daily grain meals, fasting preceded by hay only, or fasting preceded by hay and grain.
• These samples were collected sequentially every hour from three different horses that were prepared with gastric cannulas.
• The researchers also conducted experiments in vitro using the horse’s gastric mucosal tissue stripped of muscle and serosal layers. The tissue was tested with sodium taurocholate or deoxycholate (bile salts), and hydrochloric acid (HCl).

Results

• Findings revealed that gastric pH values varied with time, although there was no significant difference between the feeding protocols or the fasting period on mean pH.
• In fasted animals, bile salt concentrations averaged 0.23-0.44 mmol/l. The bile salt concentrations in fed animals were consistently below 0.2 mmol/l.
• Exposing the gastric mucosa to bile salts alone showed no significant effect, but the combination of bile salts and acid resulted in a significant decrease in electrical potential difference (PD). This suggests that both these components jointly inflict more harm on the equine gastric mucosa than acid alone does.
• The study confirmed that concentrations of bile salts and acid sufficient to alter the electrolyte transport function of the gastric mucosa can be found in the gastric contents of horses that have been deprived of feed for as little as 14 hours.

Significance

• This study’s findings suggest the potential harmful effects of combination of bile salts and acid on the gastric health of horses. Such a harmful impact becomes prominent, particularly when horses are deprived of feed for a minimum of 14 hours.
• The information from this research could be crucial in advocating for standard feeding procedures that consider the interval between feeds, and the potential impact on gastric health in horses.