Prolonged wireless measurement of intragastric pH in foals.

Abstract

BACKGROUND: The pathogenesis of gastric ulceration is not well understood in foals, and its relationship with gastric acidity requires further investigation. A wireless capsule, designed for intraesophageal pH monitoring in humans, was adapted to measure intragastric pH in adult horses. HYPOTHESIS/OBJECTIVES: To (1) determine the feasibility of wireless intragastric pH measurement in foals; (2) determine capsule attachment duration; and (3) describe the intragastric pH profiles recorded. ANIMALS: Eight healthy foals aged 24-98&#xa0;days. METHODS: Prospective interventional study. Capsules were attached to the glandular gastric mucosa under gastroscopic guidance using a hemostasis clip, and pH was recorded continuously. Gastroscopy was performed after 7 days to assess capsule attachment, or after suspected detachment based on sustained pH&#xa0;&#x2265;&#xa0;8. RESULTS: Capsules remained attached for 7 days (168&#xa0;hours) in 6 foals (75%). Capsules detached in 2 foals after 5 days (at 121 and 127&#xa0;hours). The mean of the median pH was 3.0&#xa0;&#xb1;&#xa0;0.7 and the mean percentage of time the pH was less than 4 (%tpH&#xa0;<&#xa0;4) was 74.0&#xa0;&#xb1;&#xa0;16.2%. As age increased, median pH significantly decreased (r&#xa0;=&#xa0;-0.75, P&#xa0;=&#xa0;.03) and %tpH&#xa0;<&#xa0;4 significantly increased (r&#xa0;=&#xa0;0.72, P&#xa0;=&#xa0;.05). No significant correlation was found between age and attachment duration (r&#xa0;=&#xa0;-0.23, P&#xa0;=&#xa0;.58). CONCLUSIONS AND CLINICAL IMPORTANCE: This technique enables minimally invasive, prolonged wireless intragastric pH measurement in foals. The strong negative correlation between age and pH provides additional insight into the gastric physiology of foals.