Extrahepatic biliary tract pathologies in mammalian species of zoo animals and wildlife: a review

Abstract

Mammalian species express a broad variety in the shape of their extrahepatic biliary tract. While a gall bladder is present in many species, others are lacking this organ. Evolutionary driving forces for these differences have not been determined yet, and organ-specific pathologies might present potentially influencing factors. We reviewed the literature regarding extrahepatic biliary tract pathologies reported in mammalian species of zoo animals and wildlife. Specific pathologies have been reported in the taxonomic orders Proboscidea, Chiroptera, Carnivora, Artiodactyla, Primates, Rodentia, and Lagomorpha with variable frequencies of etiological categories. While metabolic disorders with cholelith formation have been reported mainly in captive populations, parasitological infestation was found particularly in free-ranging animals. Based on the available data, we hypothesize Proboscidea, Primates, and Rodentia species to be prone to cholelithiasis. Species belonging to the Artiodactyla seem to be more susceptible to parasitological infestation while in representatives of the Carnivora infectious, metabolic, neoplastic, and parasitological disorders have been reported nearly equally. Extending our knowledge on extrahepatic biliary tract pathologies in exotic pets and wildlife will support the work of veterinary practitioners as well as scientists in evolutionary biology, making further research in this area strongly recommendable.

Cholecystoduodenostomy for biliary obstruction treatment in a white‐collared lemur (Eulemur cinereiceps)

“…This condition is highly prevalent in humans: 10–20% of the adult population in developed countries harbour gallstones, of which about 20% are symptomatic 4 . Spontaneous cholelithiasis has been described in many non‐human primate species 1 . It has been reported in galagos ( Galago crassicaudatus ), 5 slender lorises ( Loris tardigradus ), 6 marmosets ( Callithrix jacchus, Callithrix kuhlii, Callitrix argentata ), 7–10 tamarins ( Leontopithecus rosalia, Leontopithecus chrysomelas, Leontopithecus chrysopygus ), 7,9,10 squirrel monkeys ( Saimiri sciureus ), 3 owl monkeys ( Aotus trivirgatus ), 11 rhesus macaques ( Macaca mulatta ), 12,13 baboons ( Papio sp.…”

“…Although spontaneous choleliths have been documented in different primate species, strepsirrhines are rarely affected by this condition. 1 Moreover, its successful surgical treatment has never been described in this taxon. The findings of this case, which describes the diagnostic process and treatment of an obstructive cholelithiasis in a white-collared lemur (Eulemur cinereiceps), indicate that lemuriforme species may be affected by this disease and testifies the feasibility and success of its surgical treatment.…”

“…Cholelithiasis is a medical condition where one or more calculi are formed in the gallbladder, and may be associated with biliary obstruction and inflammation. Although spontaneous choleliths have been documented in different primate species, strepsirrhines are rarely affected by this condition 1 . Moreover, its successful surgical treatment has never been described in this taxon.…”

Ingesta-associated choledocholithiasis in horses: 2 cases and literature review

“…Formation of biliary tract stones (cholelithiasis), including gallbladder stones (choleliths) and common bile duct stones (choledocholiths), are relatively uncommon phenomena in animals. 16,17,20,29 Specifically, horses, which lack a gallbladder, are reported to develop choledocholiths with an estimated prevalence of 0.08%. 21 Equine choledocholithiasis can be clinically silent and only detected at autopsy; alternatively, choledocholiths can lead to cholangitis, extrahepatic biliary obstruction, hepatic fibrosis, and cholangiohepatitis, ultimately resulting in significant hepatobiliary injury and clinical signs and biochemical indices of hepatobiliary dysfunction.…”