Abstract

A 14-year-old female Sumatran orangutan was diagnosed with erratic audible breath sounds, temporary lethargic behaviour and inappetence. In 2016, the orangutan had a history of a purulent throat pouch infection which required surgical intervention combined with long-term antibiotics. Therefore, it was assumed that we were experiencing a recurrence and treated her with two antibiotic cycles over a period of four months. The improvement of her general condition was only temporary. For better diagnostics, the patient was anaesthetized and transported to the Leibniz Institute for Zoo and Wildlife Research (IZW) imaging centre. Computed tomography, ultrasound and endoscopy were performed (320-Slice computed tomography, 3D/4D ultrasound, video endoscopy). The results of the different imaging modalities were following:

• Dilated Ductus choledochus containing echo-dense biliary sludge besides the anechogenic bile (CT diagnosis confirmed by transcutaneous ultrasound)
• Clear detection of a stenosis of the duodenal papilla due to the funnel-like appearance of the bile duct (duodenal endoscopy)
• Mild inflammation in the main bronchi and moderate amount of mucus secretion in the trachea (bacteriology) and left throat pouch (tracheal endoscopy)

Her blood parameter for total bilirubin was three-fold increased (1.1 mg/dl, reference parameter: 0.3 mg/dl) as well as the other specific liver enzymes (ALT, AST, alkaline phosphatase) were moderately elevated, indicating a post-hepatic jaundice. Three weeks after the diagnosis, an endoscopic retrograde cholangiopancreatography was performed. For better endoscopic accessibility, the anaesthetized female was positioned in right lateral recumbency. No additional preconditions were necessary to visualize the two independent papillae of the Ductus choledochus and Ductus pancreaticus. The prominent, slightly greenish-stained papilla was identified as bile duct papilla. Initially, this papilla was catheterized by using flexible guidewire (0.8 mm) operated through the working channel of the endoscope followed by a special human bile duct dilator catheter system (2.0 mm), which allowed the stepwise hydraulic dilatation of the papilla and the distal part of the bile duct (6.0–8.0 mm in diameter) by inflation of different sized balloons filled with saline solution. The concentrated bile together with biliary sludge was completely removed from the bile duct by intensive flushing with physiological saline solution into the duodenum. The entire procedure took approximately 60 minutes. The orangutan received a single antibiotic injection (200 mg marbofloxacin, IM, Marbocyl 10%®, Vetoquinol®) and for 14 days (3x 300 mg ibuprofen/d, Nurofen 4%®, Reckitt Benckiser Deutschland GmbH) for pain. Recovery was normal, and no further clinical signs have been reported.

Acknowledgments

The authors would like to thank the team of chief physician Privatdozent Dr. Dirk Hartmann from the Sana Klinikum Lichtenberg for its assistance during this unique case.