Abstract: | ![]() Subcutaneous and pulmonary emphysema was observed in some cattle on farms on which outbreaks of bovine ephemeral fever (BEF) occurred. BEF virus was isolated in baby hamsters from one of the cases and cattle were injected with blood from this animal. Although the experimental animals developed typical BEF symptoms, no signs of emphysema could be detected by clinical and pathological examinations. The histopathological changes in the skeletal muscle and synovial membranes of the natural case resembled those of BEF described by Basson, Pienaar & Van der Westhuizen (1970). The lumina of the terminal and respiratory bronchioles in the lungs were obliterated by cellular debris and the muscular portion of some of these bronchioles was necrotic. The possible pathogenesis of pulmonary emphysema is discussed. |