Pathological Observation and SEM Morphological Changes of the Lungs from Artificial Infected Swine with Highly Pathogenic PRRSV

Artificially infected highly pathogenic porcine reproductive(PRRSV) and respiratory syndrome virus were used to observe the histopathological changes in the pig lungs and morphological changes of the lungs by scanning electron microscope.Fourteen healthy pigs were randomly divided into test group and control group.Ten pigs in the test group were inoculated with variant strains of PRRSV.The histopathological changes showed exudative inflammation among infected pigs at Day 9 post infection and typical interstitial pneumonitis at Day 14.Interstitial pneumonitis almost disappeared at Day 28.Scanning electron microscope observation indicates that at Day 9,the alveolar walls of infected pigs were severely destroyed.Rich components of cells were found in the alveolar space.At Day 14,the alveolar wall was thickened with massive cell proliferation at the intervals of pulmonary alveoli.The intine was coarse with high levels of cell adhesion.Using histopathology in conjunction with scanning electron microscope to observe the patho-logical changes in the lungs of PRRSV inoculated pigs has provided a new method for studying lungs infected by PRRSV.