Ultrastructural changes in the pulmonary airways of pigs infected with a strain of Aujesky's disease virus
Baskerville, A.
Research in Veterinary Science 13(2): 127-132
1972
ISSN/ISBN: 0034-5288 PMID: 5036312 Document Number: 50406
Thirty-two 4-week-old pigs were killed at intervals of 1 to 14 days after infection. Inflammatory changes in the lungs were divisible into an acute stage lasting from 1 to 6 days and a repair phase which commenced on the 4th day and continued until the 14th day. The virus attacked and multiplied in all types of cells and caused necrosis of the epithelium of bronchi, bronchioli and small airways. Necrosis frequently extended through the basement membrane with destruction of smooth muscle and connective tissue cells and fibres. Cellular debris and fibrin were removed by the activity of macrophages, which first appeared on the 4th day after infection. Organisation was carried out by fibroblasts, and collagen and elastic fibres were formed in the lumina and walls of airways between the 7th and 14th days. Epithelium was replaced by invasion by epithelial cells which later underwent mitosis followed by differentiation.