The purpose of this study was to evaluate the influence of gastric irrigation on intestinal motility in horses. Twelve healthy horses with a normal gastrointestinal tract were examined according to a defined protocol. The horses where submitted to four different test conditions. The two variables were water temperature and feeding status.
All 12 horses were examined after being fasted for a minimum of 12 hours, followed by an examination after feeding. The horses were flushed via a naso-gastric tube with 20 liters of water at a temperature of 18°C, as well as an instillation of 20 liters at 37°C in both a fasted and fed condition (fasted, flushed at 18°C/fasted, flushed at 37°C/fed, flushed at 18°C/fed, flushed at 37°C). To determine the number of intestinal contractions, gut sounds were auscultated for one minute in each of the four quadrants (left dorsal, left ventral, right dorsal, right ventral). This was followed by ultrasonographic imaging of the duodenum and a count of duodenal contractions over five minutes. Additionally, the duodenal diameter was measured at right angles (outer edge to outer edge) during maximum contraction and dilation. This protocol was repeated for each of the 12 horses in all four experimental conditions. If possible, the jejunum was imaged in the ventral abdomen and jejunal diameters were sonographically measured during maximum contraction and dilation. After instillation of 18°C warm water, fasted horses showed a significant increase of intestinal contractions in the right dorsal quadrant during auscultation. Additionally peristalsis increased significantly in the right ventral and left dorsal quadrant after infusion with 37°C warm water. Fed horses did not show significant results. Water infusion significantly raises the number of intestinal contractions in fasted horses, while the warmer temperature activates several bowel sections. Horses fasted for 12 hours in this study showed significantly fewer duodenal contractions and dilations than fed horses.
Water instillation caused a highly significant increase in duodenal motility in both fasted and fed horses, while water temperature did not significantly influence duodenal peristalsis. Ultrasonographically, more duodenal contractions were seen with water infusions at body temperature. The duodenum was significantly more dilated following water flushes than before. This effect was not seen in fasted horses with flushes at a temperature of 18°C. This pilot study showed that gastric water irrigation significantly increased duodenal motility in all four examination conditions. Fasted horses also demonstrated a significant elevation of peristalsis during auscultation. It is assumed that gastric water flushes stimulate peristalsis in several bowel sections. A stronger peristaltic reaction is seen with water at body temperature. Further studies are needed to evaluate the duration of this effect and to test this stimulus in horses with gastrointestinal disease.
ultrasonograhy / horse / auscultation / flushing / naso-gastric tube / gut motility / peristalsis / fed / fasted / water temperature