Evaluation of Gastroesophageal Reflux in Anesthetized Dogs with Brachycephalic Syndrome

Brachycephalic airway syndrome may predispose to gastroesophageal reflux (GER) because of the high negative intrathoracic pressures required to overcome conformational partial upper airway obstruction. To investigate this, 20 dogs presenting for elective correction of brachycephalic airway syndrome (cases) and 20 non-brachycephalic dogs (controls) undergoing other elective surgeries were prospectively enrolled. Dogs underwent a standardized anesthetic protocol, and esophageal pH was monitored. Signalment, body weight, historical gastrointestinal and respiratory disease, complete blood count, serum biochemical values, radiographic findings, and anesthetic and surgical time were compared between cases and controls, and dogs that did and did not have basic (pH > 7.5), acidic (pH < 4), or any GER. Controls had higher mean esophageal pH (6.3) compared to cases (5.6, P = .019), but there was no difference in % with GER (cases 60%, controls 40%, P = .34). When all dogs were evaluated, dogs with GER had increased creatinine (P = .01), % positive for esophageal fluid on radiographs (P = .05), and body weight (P = .04) compared to those without GER. GER was common in both cases and controls, and cases had lower esophageal pH; however, greater numbers are required to determine if a true difference exists in % GER.