Special Veterinary Pathology

Porcine enzootic pneumonia

PORCINE ENZOOTIC PNEUMONIA OF SWINE

Etiology

• Mycoplasma hyopneumoniae, M. hyorhnis, M. flocculare 

Clinical signs

• Subnormal weight gain, chronic cough, high morbidity and low mortality rates

Gross lesions

• Seen in apical and cardiac lobes of the lung with consolidation and atlectasis, enlarged peribronchial lymph node, serofibrinous pleuritis, peritonitis and pericarditis

Microscopic lesions

• Peribronchial and peribronchiolar accumulation of lymphocytes and plasma cells in large numbers
• Mucus secreting cells in brochial and bronchiolar epithelium produce excess activity
• Neutrophils, lymphocytes, plasma cells accumulate in between the alveoli and inside alveoli