Bacillary Necrosis

• Fusobacterium necrophorum
• calves and lambs
• common in intensively reared beef cattle
• occurs following an infected umbilicus in neonates and from rumenitis in adult cattle

Gross

• rounded pale multiple foci of coagulative necrosis throughout the liver
• unsoftened, greyish-yellow patches
• ringed by a zone of hyperaemia
• foci coalesce in severe cases
• in adult animals, these lesions may have progressed to abscesses following lysis of the coagulated necrotic tissue and the formation of fibrous capsule around the damaged tissue
• if animal survives, these lesions may soften develop into abscesses

Microscopically

• coagulative necrosis
• possible evidence of migrating flukes
• bacteria can be demonstrated in the periphery of the necrotic tissue, especially near its junction with viable tissue
• there is a rim of neutrophilic cells