The liver of a 4-year-old cow was examined within 1 h of slaughter at an abattoir in Queensland, Australia. The liver was condemned due to a visible surface abscess, approximately 4 to 5 cm diameter, protruding from the visceral surface of the left hepatic lobe, with a fibrous wall about 2 cm think. It contained semi-fluid, creamy yellowish material centrally. The rest of the liver was normal. M. wolfii was isolated from the lesion in pure culture without bacterial contamination. Histological examination of the abscess revealed clumps of bacteria arranged in filaments close to the inner wall, which were Gram-negative, stained black with Grocott and were morphologically consistent with Fusobacterium necrophorum. The appearance of the abscess, with vasculitis, was therefore probably due to a combination of the fungal and bacterial infection.