Hyperostotic bone disease in a wombat (Vombatus ursinus)

Little is known about wombat diseases in general, and about their congenital diseases in particular. In the current study, the skeleton of a common wombat (Vombatus ursinus) that exhibited generalized hyperostosis is analyzed, and possible diagnoses are reviewed. Macromorphological analyses revealed that the diaphyses of the long bones manifested an increased diameter with extensive diaphyseal new-bone formation (periosteal and endosteal). Cross-sections of the diaphyses showed that the cortical-medullary demarcation was indistinct. The calvarial bones were thickened. Radiographs showed uniform sclerosis of the long bones with loss of trabecular pattern. Microradiography showed extensive bone remodeling, a hyper-vascularized lamellated layer of bone and numerous linear formation defects. Possible causes for the lesions, including sclerosing bone dysplasia disorders, acquired syndromes causing hyperostosis, and metabolic diseases typical of animals in captivity, are discussed.