Contrast videofluoroscopy is the imaging technique of choice for evaluating dysphagic patients because it allows for assessment of anatomic and functional components of swallowing. In people, body position significantly alters the outcome of videofluoroscopic assessment of swallowing. The purpose of this study was to determine if quantitative videofluoroscopic measures of swallowing were significantly affected by body position in dogs.

Healthy dogs (n=15) with no history of dysphagia were recruited for this study. Dogs had normal physical examinations, CBC's, and serum biochemistry panels. A restraint device was built to facilitate imaging of dogs in sternal recumbancy. Each dog underwent videofluoroscopy of swallowing of liquid barium and barium soaked kibble in sternal and lateral recumbancy. Quantitative measures of liquid and kibble swallowing (timing of swallowing, pharyngeal constriction ratio, esophageal transit time, and number of esophageal peristaltic waves) were compared between body positions. The number of radiation safety violations per second was determined.

The time to opening of the upper esophageal sphincter was significantly longer for lateral versus sternal kibble swallows (p=0.043). In lateral recumbency, 54% of liquid and 71% of kibble swallows stimulated esophageal peristalsis. In sternal recumbency, 81% of liquid and 90% of kibble swallows stimulated esophageal peristalsis. Significantly fewer radiation safety violations occurred in sternal versus lateral esophagrams (p=0.003). Other variables were not significantly different.

Body positioning affects the number of swallows that result in esophageal peristalsis. Radiation exposure to technical staff is significantly reduced for esophagrams performed in sternal recumbency.