Technique for Evaluation of Gravity-Assisted Esophageal Transit Characteristics in Dogs with Megaesophagus

Movement of food material in the esophagus during upright feeding in dogs with megaesophagus (ME) is poorly characterized. A standardized contrast videofluoroscopy technique was used to evaluate esophageal transit characteristics in dogs with ME while in an upright position. Twelve dogs with ME (congenital, acquired idiopathic, or secondary to myasthenia gravis) were placed in an upright position using Bailey chairs and given liquid barium, canned food meatballs, and their normal diet consistency if different than meatballs. Passage of ingesta was videofluoroscopically evaluated by direct observation and change in ingesta area as determined by manual tracing or barium column product calculations. Significant individual variation was seen. Complete esophageal clearance of liquid was seen in four dogs, and complete clearance of meatballs in three dogs, with a median time of 5 min for both. Two of seven dogs fed a slurry diet had complete clearance by 10 min. No significant difference was found between area calculated via tracing or barium column product. Based on imaging results, alterations in food consistency, duration upright, or medication were recommended for nine dogs. In dogs with ME accustomed to a Bailey chair, contrast videofluoroscopy was technically straightforward and allowed for more specific physician-guided management recommendations.