Esophagoscopy and Gastroscopy
Equine

Indications for performing this procedure:  Esophagoscopy and gastroscopy are important diagnostic aids in cases of equine gastrointestinal malfunction.  Visualization of the upper gastrointestinal tract facilitates diagnosis of such conditions as choke, esophageal strictures, esophageal and gastric neoplasia, and gastric ulcers.  In order to definitively diagnose growths in the esophagus and stomach, endoscopy can aid in retrieval of a biopsy specimen.


The Procedure and Equipment: The adult horse should be moderately tranquilized for the standing procedure.  The neonate can also be sedated, though it is often unnecessary.  Foals can nurse up to four hours prior to the procedure, but adults should be fasted for 6-10 hours previous to intubation.

    In the adult horse, visualization of the proximal esophagus requires an endoscope with at least 1 m of working length.  In the normal animal, the esophageal mucosa should be glistening, and whitish-tan to pale pink with transverse and longitudinal folds clearly visible.  To see the whole esophagus in most horses, a 170-190 cm tube is necessary; a 200-cm tube will reach the stomach in all warm-blooded breeds.  Visualization of the pylorus (duodenoscopy) requires a tube of 280-300 cm long.  The external diameter of the tube ranges from 10-14.5 mm.  The smaller size is necessary for foals, while the larger sizes are only safely used in older yearlings to adults.  Most veterinary practices have an endoscope with an insertion tube of 100 -110 cm long, and 10 -14.5 mm wide.


References: