Polyorgan Failure in a Captive Brown Bear (Ursus arctos). A Clinical Case Description

Brown bears are kept in various captive conditions, some of which can significantly deteriorate their health. Hyperadrenocorticism, caused by a hormonal disorder resulting from prolonged captivity and stress factors, and leading to multiple organ failure, has not been previously observed or described in bears. Increased cortisol secretion not only leads to damage of internal organs but also to diabetes mellitus, decreased immune resistance, and consequently, to the loss of the immune system’s ability to recognize and destroy pathogenic microorganisms. In literary sources, there are reports of deaths of animals living in captivity as a result of bacterial infections (for example, generalized clostridiosis in the Himalayan bear, pulmonary nocardiosis in the Pacific bottlenose dolphin, fungal lung disease in reindeer). However, none of these studies conducted detailed post-mortem and histological examinations of all organs. The clinical case of multiple organ failure in a brown bear in a zoo setting presented by us combines anamnestic data, symptomatology, results of laboratory and instrumental parameters during the animal’s life, as well as the results of pathomorphological, histological, and histochemical examinations. These data allow us to recommend that zoos minimize stress factors for animals in their care, resort to pharmacological correction of stress if necessary, and conduct quarterly health check-ups for early detection of disease and timely and targeted therapy.