Fig. 3

Histopathological lesions of the lung from HP-PRRSV infected and control piglets. At necropsy, lung samples were collected and processed for histopathology examination following hematoxylin and eosin (H&E) staining. Lungs of piglets infected with HP-PRRSV (b) showed severe interstitial pneumonia with thickened the alveolar septa (marked with arrows) accompanied by significant infiltration of mononuclear cells, compared to the lungs of negative control piglets (a)