Abstract
Background:
Lung tumors in dogs, significantly primary paragangliomas, are rare and have not been reported. This report describes a dog with a lung tumor diagnosed as a primary paraganglioma.

Case Description:
A 12-year-old spayed French bulldog presented with a left-sided pulmonary mass. The dog was in good general condition and had no clinical symptoms. Computed tomography (CT) revealed a pulmonary mass near the bifurcation of the posterior lobe bronchus of the left lung. The mass showed a strong contrast enhancement effect that was subsequently attenuated. The dog underwent Surgery to remove the mass from the left lung. Abnormal hypertension was observed during surgery, and hypertensive crisis was suspected. Based on the histopathology and preoperative and postoperative urinary metanephrine and normetanephrine levels, the dog was diagnosed with primary paraganglioma of the lung. Although the CT scan showed findings suggestive of the development of a neuroendocrine tumor, it was difficult to suspect the development of a paraganglioma.

Conclusion:
The possibility of catecholamine-producing tumors should be considered when we encounter a lung tumor with no clinical symptoms and a neuroendocrine tumor like contrast enhancement pattern on CT scan.

Key words: Canine, Dog, Paraganglioma, Pulmonary