Abstract: Background – Hospitalized brachycephalic dogs are potentially at an increased risk of regurgitation and aspiration pneumonia. Large gastric residual volume (GRV) has been suggested as a risk factor for aspiration, yet this association lacks supporting evidence in dogs and remains controversial in human medicine. In pediatric human patients, GRV >5mL/kg is considered elevated, but no veterinary studies have investigated the relationship between GRV and incidence of regurgitation or aspiration pneumonia in dogs. Moreover, routine evaluation of GRV in an asymptomatic patient may result in complications such as inappropriate delay of nutrition or tube clogging. Hypothesis/objectives- GRV >5mL/kg would not be associated with increased incidence of regurgitation or aspiration pneumonia in hospitalized brachycephalic dogs. Animals - 52 brachycephalic dogs evaluated at a tertiary hospital between March 2021-December 2023 with documented GRV measurements, recorded episodes of regurgitation, and radiographic confirmation of aspiration pneumonia when present. Methods – Retrospective records review from March 2021-December 2023. Results – A total of 59 GRV >5mL/kg,99 regurgitation events and 5 cases of aspiration pneumonia were documented. Negative binomial mixed-effects analysis revealed no significant association between GRV >5mL/kg and regurgitation events (p=0.4). Binary logistic regression analysis similarly found no significant relationship between GRV >5mL/kg and aspiration pneumonia diagnosis (p=0.9), or between regurgitation frequency and aspiration pneumonia diagnosis (p=0.6). Conclusions and Clinical Importance- GRV >5mL/kg was not associated with regurgitation or aspiration pneumonia in this population of hospitalized brachycephalic dogs. Routine monitoring of GRV in the absence of other clinical signs such as abdominal distension is not recommended.
