Septic Pleuro-Pneumonia in Ruminants and Pigs. 289 



The new born are most subject to the affection, the germs evi- 

 dently entering through the umbiUcus. After six weeks of age 

 the period of danger from infection has passed. Calves born in 

 an infected building suffer, as do those brought from sound herds 

 into such a building shortly after birth. If, however, the dam 

 has been moved into a fresh, non-infected stable a few days 

 before parturition, the progeny born there usually escapes 

 (Trincherd). 



Spoilt, impure food, foul, close air, crowding, and unclean 

 stables doubtless contribute to its propagation, yet it will develop 

 and persist in the most admirably appointed buildings in appar- 

 ently the most abundant and purest air, and with food and water 

 that appear to be above suspicion. Even a thorough purifica- 

 tion and disinfection of the barn will sometimes fail to check it, 

 so that we must suspect that it attaches for a time to the indi- 

 vidual animal in certain cases. In this connection Galtier attrib- 

 utes a coincident abortion in the dams to the propagation of the 

 same microbe, and in such cases the calves may be already dis- 

 eased at birth. 



Prognosis. The mortality varies from 20 to 25, and in some 

 outbreaks up to 66 per cent. In the most fatal type occurring 

 within one or two days after birth the mortality is still higher. 

 (See Vol. IV, p. 645). 



Lesions, i. Calves. In acute cases the pleura contains a red- 

 dish, yellowish or milky liquid which may be so abundant as to 

 cause compression and collapse (atelectasis) of the lungs. The 

 affected portion of the lung is filled with a liquid, giving a yel- 

 lowish color and a great increase of thickness to the interlobular 

 tissue as in cases of lung plague, the contrast being strongly 

 marked between the red parenchyma, and the yellow interlobular 

 tissue. In case of blood extravasation, however, the color may be 

 uniform. The surfaces of the pleura and bronchial mucosa show 

 more or less petechise. The coagulated exudate may bind the 

 lung to the ribs. In the bronchia and trachea the exudate may 

 be serous with loose coagula, and even streaks of blood, and 

 patches of congestion and petechise may be seen on the laryngeal 

 and nasal mucosa, and in other parts of the body. In more ad- 

 vanced and chronic cases, the lungs may be solidly hepatized or 

 they may on section show gray hepatization, or caseation. The 

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