Actinobacillus pleuropneumonia in pigs causes which nasal sign?

• A. Watery discharge
• B. Bloody froth discharge
• C. Purulent discharge
• D. No discharge

Answer: (B)

Actinobacillus pleuropneumoniae causes an acute, hemorrhagic pneumonia with pleuritis, so the nasal signs reflect the severe pulmonary hemorrhage. The characteristic finding is a bloody, frothy nasal discharge, produced by blood from damaged airways mixed with edema fluid and airway secretions as the disease rapidly progresses. This contrasts with a simple watery discharge seen in milder viral infections, purulent discharge typical of some chronic bacterial infections, or no discharge at all when the nasal symptoms are absent. So the presence of bloody froth discharge fits the hemorrhagic nature of APP-driven pneumonia in pigs.