06.07.2022: Traditional medicine in Southeast Asia and China often incorporates ingredients derived from animals. Asiatic black bears (Ursus thibetanus), for example, are harvested for their bile. The bile is extracted from captive animals up to several times a week – a procedure that often leads to inflammation of the gallbladder. In their study, an international team led by researchers from the Research Institute of Wildlife Ecology at Vetmeduni, in cooperation with the animal welfare association Four Paws, investigated possible methods of diagnosing and treating gallbladder inflammation.

Across Southeast Asia and China, more than 17,000 Asiatic black bears are farmed for their bile under extremely poor conditions to meet the demand for traditional medicine products. Years of unsterile bile extraction often causes chronic gallbladder inflammation and considerable suffering to the animals. In both human and veterinary medicine, the diagnostic value of macroscopic bile examinations (diagnosis with the naked eye) for assessing gallbladder disease remains unclear.

The objective of the study was to identify the role of gallbladder colour, viscosity and turbidity and to compare these observations with established markers of gallbladder inflammation. The researchers also aimed to define the optimal duration of oral antibiotic treatment for treating chronic bacterial gallbladder inflammation in bile-farmed bears.

Large-scale examination of bile samples

The researchers examined 39 formerly bile-farmed adult Asiatic black bears under anaesthesia and for further evaluation performed percutaneous ultrasound-guided cholecystocentesis (PUC), a technique in which bile is collected through a small puncture. PUC is considered the diagnostic gold standard for gallbladder inflammation and is associated with very low complication rates. A total of 59 bile samples were taken during standard veterinary health checks, with 20 animals sampled twice to evaluate the therapeutic success. All bile samples were examined macroscopically and microscopically, followed by analysis for bacterial cultures and antimicrobial sensitivity.

Antibiotic treatment over 30 days found effective in resolving gallbladder inflammation in bears

“In the majority of bears, samples with microscopic evidence of bacterial infection lacked inflammatory cells and did not always correlate with positive bacterial cultures. The most common bacterial isolates were Enterococcus spp., Streptococcus spp. and Escherichia coli. Based on our findings, the optimal duration of antibiotic treatment for chronic bacterial gallbladder inflammation is 30 days,” says the study’s first author, Szilvia K. Kalogeropoulu from the Research Institute of Wildlife Ecology at Vetmeduni.

First data on the diagnostic value of macroscopic bile examination

Another important finding, according to the study’s last author Johanna Painer-Gigler from the Research Institute of Wildlife Ecology at the University of Veterinary Medicine Vienna, concerns the diagnosis of gallbladder inflammation in formerly bile-farmed bears: “Unlike gamma-glutamyl transferase (GGT) and gallbladder wall thickness, the organoleptic properties of bile were found to be reliable markers of chronic gallbladder inflammation, with colour and turbidity indicating cholestasis [reduction or stoppage of bile flow].” The current study highlights the importance of cholecystocentesis for the diagnosis and successful treatment of gallbladder disease and provides initial results on the potential diagnostic value of macroscopic bile examination.

The article “Chronic cholecystitis: Diagnostic and therapeutic insights from formerly bile-farmed Asiatic black bears (Ursus thibetanus)” by Szilvia K. Kalogeropoulu, Emily J. Lloyd, Hanna Rauch, Irene Redtenbacher, Michael Häfner, Iwan A. Burgener, Johanna Painer-Gigler was published in PLOS ONE.

Scientific article