Treatment of a retroperitoneal abscess by omentalization in an orangutan (Pongo pygmaeus pygmaeus).

A 38-yr-old orangutan (Pongo pygmaeus pygmaeus) presented with chronic lethargy and difficulty in locomotion that progressed to weakness, anorexia, and permanent dorsal and/or lateral recumbency. The orangutan was immobilized with ketamine. Abdominal ultrasonography revealed a mass in the caudal portion of the abdomen. Exploratory surgery was performed, but the mass could not be resected. Instead, the mass was drained and omentalized in an attempt to establish continuous drainage after surgery. The only complication was a wound infection that was treated locally with a disinfectant and installation of a drain that was changed every 2 days under anesthesia. Omentalization was successful in providing continuous fluid drainage for this retroperitoneal abscess and required minimal postoperative handling of the animal.