Vegetative endocarditis associated with Arcanobacterium haemolyticum in a Holstein cow

A 4-year-old Holstein cow with progressive atrophy and ataxia was submitted for diagnosis. The postmortem examination revealed multifocal yellowish nodules in the pulmonary parenchyma and vegetative masses in the mitral and tricuspid valve of the heart. Both kidneys were severely enlarged, with multiple yellow nodules on the parenchyma. Histopathologically, pulmonary abscesses, vegetative endocarditis, suppurative glomerulonephritis, and fibrino-purulent arthritis were observed. The tiny β-hemolytic bacterial colonies were isolated from the lesions and identified as Arcanobacterium haemolyticum by the Vitek 2 system (bioMérieux, USA). This is the first documented report of an A. haemolyticum infection in a Holstein cow in Korea.