Esophageal pH monitoring in dogs with reflux signs

Abstract

BACKGROUND: Although gastroesophageal reflux (GER) often is assumed to be causative for upper gastrointestinal and respiratory signs in dogs, no attempts have been made to verify this assumption. OBJECTIVES: To monitor esophageal pH with the Bravo pH system in healthy dogs and client-owned dogs displaying signs commonly attributed to GER. ANIMALS: Seven healthy and 22 client-owned dogs. METHODS: After routine esophagogastroduodenoscopy, radiotelemetric pH capsules were placed in distal esophagus for continuous pH recording. Reflux was defined as single pH measurement <4. At discharge, owners were instructed to press individually predefined clinical sign-buttons on the receiver whenever indicated. Results between groups were compared using Mann-Whitney U-test. RESULTS: The median (range) number of refluxes in client-owned and healthy dogs, respectively, was 17 (1-205) and 10 (1-65), the number of refluxes >5 minutes in duration was 1 (0-14), and 1 (0-4), duration of longest reflux (min) was 10 (0-65) and 8 (0-27), and fractional time pH <4 (%) was 0.76% (0.01-6.28), and 0.3% (0-3.1). No differences were found between groups. The median of 7 (1-35) clinical sign-button pushes were recorded in 21 dogs. Median of 12.5% (2.8% [1/35]-50% [2/4]) reflux-positive clinical sign-button pushes was found in 10 dogs with reflux-positive pushes. Five (22.7%) dogs had increased esophageal acid exposure, and mild esophagitis was noted in 1 dog. CONCLUSION AND CLINICAL IMPORTANCE: Despite evidence of increased GER in some dogs, the clinical sign-reflux association remained poor. Future investigation should focus on dogs with esophagitis.