Septic arthritis and osteomyelitis in a bovine digit: a mixed infection of Actinomyces pyogenes and Fusobacterium necrophorum.

A 4-year-old beefmaster cow was examined for a left hind leg lateral claw lameness due to septic arthritis of the distal interphalangeal joint and associated osteomyelitis of the second and third phalanges. Actinomyces pyogenes and Fusobacterium necrophorum, which have been demonstrated previously to act synergistically in ovine heel abscesses, were isolated from the affected digit. A claw amputation was performed because of the advanced destructive nature of the lesion.