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 5 15). Methods: Interventional, experimental study. A restraint device was built to facilitate imaging of dogs in sternal recumbancy. Each dog underwent videofluoroscopy during swallowing of liquid barium and barium-soaked kibble in sternal and lateral recumbancy. 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 AE 1.98 versus 7.23 AE 3.11; P 5 .001) and kibble (4.44 AE 2.02 versus 8.92 AE 4.80; P 5 .002). In lateral recumbency, 52 AE 22% of liquid and 73 AE 23% of kibble swallows stimulated primary esophageal peristalsis. In sternal recumbency, 77 AE 24% of liquid (P 5 .01 versus lateral) and 89 AE 16% of kibble (P 5 .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.

Diagnostic outcome of contrast videofluoroscopic swallowing studies in 216 dysphagic dogs

“…Bolus transit time through the cervical and thoracic portions of the esophagus was measured as previously described . The cervical esophagus was defined as the portion of the esophagus extending from the caudal aspect of the upper esophageal sphincter to the thoracic inlet.…”

“…Another limitation was that all swallow studies were performed with dogs positioned in lateral recumbency in contrast to the more natural sternal or standing positions. Esophageal transit times in dogs are significantly altered by body position . However, at our institution, swallow studies in dogs are most commonly performed with the animal in lateral recumbency due to the challenges of preventing motion artifact and difficulty restraining the animal in sternal or standing positions.…”

The prevalence of dynamic pharyngeal collapse is high in brachycephalic dogs undergoing videofluoroscopy

“…As with other cases of pharyngeal collapse that have been described in the veterinary literature, dogs in the current study were imaged in lateral recumbency. Body position (lateral versus sternal) has been shown to effect esophageal transit time derived from videofluoroscopic swallowing assessment, although body position did not influence pharyngeal contraction or bolus transit time from the pharynx through the upper esophageal sphincter in healthy dogs . Further studies are warranted to assess the effects of body position on the presence of pharyngeal collapse.…”

Esophageal Dysfunction in Dogs with Idiopathic Laryngeal Paralysis: A Controlled Cohort Study

“…In humans, esophageal motility decreases with advanced age and this may also be true for geriatric dogs 52–54 . Additionally, all dogs were positioned in lateral recumbency for the esophagrams, which may affect bolus transport through the esophagus 55 . It would be ideal, and probably more comfortable for the dog, if the esophagrams could be performed in sternal or standing positions.…”