160 



SWINE PRACTICE 



driven to market, especially when they become very hot. It is rather 

 common as a secondary condition in acute cases of pneumonia, svi^ine 

 plague, and hog cholera. 



Cause. — Engorgement of the lung capillaries, due to overexertion, 

 excessive heat, or disease, is the chief cause of hemorrhage. "Weak- 

 ening of the vessel walls due to malnutrition, which occurs in some 

 infective diseases, is another cause. 



Diseased lobes of lungs 



Fig. 



30. Hog lungs with inflammation of anterior lobos as a result of 

 chronic swine plague. (Ostertag.) 



Lesions. — Almost all cases of hemorrhage of the air passages pos- 

 terior to the larynx are designated hemoptysis, or pulmonary hemor- 

 rhage, and it is difficult in some instances to differentiate tracheal 

 or bronchial hemorrhage from pulmonary hemorrhage. If the hemor- 

 rhage is primary the escaped and escaping blood is practically all 

 that will be observed. The blood that escapes from the lung or 

 smaller bronchial tubes will contain more entangled air, that is, be 



