Special Veterinary Pathology

NOCARDIOSIS

Definition

• Purulent, necrotizing occasionally granulomatous lesions in lungs, pleura or skin caused by Nocardia asterioides.

Aetiology

• Nocardia asterioides

Incidence

• Affects dogs and cattle

Gross lesions

• Infection in the lung and pleura is most common in dog
• In systemic ionfection, organisms can localize in peritoneal and pleural cavities

Microscopic lesions

• Organisms surrounded by necrotic cellular debris, purulent exudates and granulation tissue with a zone of macrophages, lymphocytes, plasma cells and giant cells and fibrous connective tissue.
• Filamantous organisms resembles Actinomyces sp. but are acid fast and gram positive
• Mastitis, pneumonia and abortion in cattle

Diagnosis

• From tissue sections Cultural Examination