Abstract
Pathological examination was made on 48 cases of pneumonic lungs in cattle and calves, which had been collected in Miyagi and Tochigi Prefectures between April 1973 and March 1974. From those cases T-mycoplasmas were isolated at a high incidence, particularly from 90% of Cases under 6 months of age. Pneumonic lesions were characterized by bronchitis or bronchiolitis, catarrhal bronchopneumonla, suppurative bronchopneumonia, or others including fibrinous and interstitial pneumonia and atelectasis. Severe suppurative bronchopneumonia was seen in many calves under 6 months of age, while mild bronchitis or bronchiolitis and catarrhal bronchopneumonia were predominant in many cases 7 to 24 months of age. In many cases having only mycoplasmas without common bacteria, bronchitis or bronchiolitis and catarrhal bronchopneumonia were seen with peribronchial or peribronchiolar lymphoid hyperplasia, suggesting that severe pneumonia including suppurative or fibrinous pneumonia may result from the secondary participation of common bacteria isolated frequently in such lesions.
