Radiographic and ultrasonographic evaluation of the esophagus in the horse

Abstract

The purpose of this study was to describe the radiographic and ultrasonographic appearance of the esophagus of ten healthy horses. Contrast radiography showed variations in the long-axis shape of the esophagus at the thoracic inlet. Administration of a large volume contrast medium by intubation showed stasis of contrast material for several minutes in two of the ten horses. The wall thickness of the non-distended esophagus on ultrasound was 2.6 ± 0.3 mm with significant differences depending on the location. Distention of the esophagus by intubation or by a bolus of water or concentrate resulted in a decrease in wall thickness and it facilitated measuring with less variation. Stasis at the thoracic inlet was seen in five of the ten horses, when a water bolus was administered. Ultrasonographic evaluation of 100g spontaneously swallowed commercial concentrate was better than fluid (water bolus or 2.5mL/kg contrast medium) administration via intubation to assess esophageal motility at the thoracic inlet. Stasis seen at the thoracic inlet after bolus administration by intubation should not be regarded as an abnormal finding, and swallowing, with the subsequent peristaltic wave, has a positive influence on the bolus passage time.