Rumenitis

Neutrophilic inflammation

• Opportunistic pathogens take advantage of acidotic lesions and other disturbances of rumen flora.
  • e.g. F. necrophorum, fungi
  • Infection with Mucor gives mucormycosis- chronic ongoing granulomatous rumenitis.
  • Also agents which cause lesions in other areas of tract e.g. BVDV, actinobacillosis.

Pathology

Gross

• Multiple, dark red areas of swollen papillae, mainly in ventral sac and pillars.

Histological

• Coagulative necrosis of papillae
• Marked neutrophil infiltrate
• Serofibrinous exudate
• Thromboembolic spread to form areas of coagulative necrosis and abscesses in liver.