Effects of body positioning on swallowing and esophageal transit in healthy dogs.

Abstract

BACKGROUND: Contrast videofluoroscopy is the imaging technique of choice for evaluating dysphagic dogs. In people, body position alters the outcome of videofluoroscopic assessment of swallowing. HYPOTHESIS/OBJECTIVE: That esophageal transit in dogs, as measured by a barium esophagram, is not affected by body position. ANIMALS: Healthy dogs (n=15). METHODS: Interventional, experimental study. A restraint device was built to facilitate imaging of dogs in sternal recumbency. Each dog underwent videofluoroscopy during swallowing of liquid barium and barium-soaked kibble in sternal and lateral recumbency. Timing of swallowing, pharyngeal constriction ratio, esophageal transit time, and number of esophageal peristaltic waves were compared among body positions. RESULTS: Transit time in the cervical esophagus (cm/s) was significantly delayed when dogs were in lateral recumbency for both liquid (2.58+/-1.98 versus 7.23+/-3.11; P=.001) and kibble (4.44+/-2.02 versus 8.92+/-4.80; P=.002). In lateral recumbency, 52+/-22% of liquid and 73+/-23% of kibble swallows stimulated primary esophageal peristalsis. In sternal recumbency, 77+/-24% of liquid (P=.01 versus lateral) and 89+/-16% of kibble (P=.01 versus lateral) swallows stimulated primary esophageal peristalsis. Other variables were not significantly different. CONCLUSIONS AND CLINICAL IMPORTANCE: Lateral body positioning significantly increases cervical esophageal transit time and affects the type of peristaltic wave generated by a swallow.