Pneumonia following experimental bronchial obstruction in sheep

Five of 7 sheep in which the bronchi supplying the right apical lobe of the lung were obstructed with a cottonwool plug developed pneumonia. Large numbers of bacteria were isolated from 4 of the 5 pneumonic lungs. Only minor pulmonary lesions, which are common in sheep on pasture, were observed in 5 sham operation and 5 control sheep. These results support a role for airway obstruction in compromising the antimicrobial defences of the lungs in naturally occurring bacterial pneumonias of sheep.