Disseminated nocardiosis in a Japanese raccoon dog (Nyctereutes procyonoides viverrinus).

Abstract

A captive male Japanese raccoon dog died after self-mutilation by biting its tail and developing anorexia. At necropsy, ulceration of the tail root and pelvic region, an abdominal mass, multifocal nodules in the lungs, and thrombi in the heart were observed. Histopathological examinations revealed multifocal pyogranulomatous inflammation in the lungs, abdominal mass, spleen, brain, liver, and kidneys. Gram-positive bacterial aggregates were observed in the lungs, abdominal mass, and spleen. These organisms were partially acid-fast and periodic acid-Schiff-positive, and branching filaments were observed on Grocott's methenamine silver staining. Nocardia aobensis was identified in the abdominal mass by PCR and sequence analysis. These findings suggest that N. aobensis should be considered a potential cause of disseminated pyogranulomatous disease in animals.