Pulmonary vein aneurysm in a New Zealand White rabbit: a case report

Background: Pulmonary venous aneurysm (PVA) is a rare condition characterized by aneurysmal dilatation of the pulmonary vein in humans. The diagnosis is incidental usually as there are no clinical symptoms. This case report describes a histological diagnosis of PVA in a New Zealand White rabbit. Case presentation: A 1.5-kg male New Zealand White rabbit was acclimatized in an animal room for 5 weeks until the experiment began. However, the rabbit was found dead, with signs of nasal hemorrhage. Necropsy revealed tracheal and pulmonary hemorrhage, and the epistaxis had a pulmonary origin. PCR and ELISA to detect antigens and antibodies pertaining to the rabbit hemorrhagic disease virus showed negative results. Multiple ballooning lesions (50–200 μm size) in the pulmonary veins were observed on histological examination, and PVA was diagnosed. Death was attributed to a spontaneous rupture of the PVA and massive hemorrhage into the lung parenchyma that extended into the trachea and nasal passages. Conclusions: To the author’s best knowledge, this is the first report of a PVA in a rabbit.