Pleuritis and pericarditis associated with Klebsiella pneumoniae in a Eurasian beaver (Castor fiber)

An adult one-year-old male Eurasian beaver (Castor fiber) died of a traumatic injury to its right leg from a fall. At necropsy, fibrinopurulent exudates were observed in the thoracic cavity. Histopathologic examination showed that the pericardium, thoracic wall, pulmonary pleura and the lungs were markedly thickened due to mixtures of necrotic cellular debris, neutrophils, fibrin, red blood cells, and bacterial aggregates. Pure culture of Klebsiella (K.) pneumoniae was isolated from the thoracic exudates, pleura and heart tissues. Based on these findings, this is the first report describing pleuritis and pericarditis associated to K. pneumoniae in a beaver.