DISEASES OP RESPIRATOBY ORGANS , 165 



denced by rise of temperature and the associated cardiac and respira- 

 tory disturbances. 



Treatment. — No special line of treatment is of value. The animals 

 should be placed in good quarters and cared for properly. 



An infectious pneumonia of swine caused by streptococci has been 

 observed in a few instances. The source of infection and the avenue 

 of entrance has not been determined. The infection appears to be 

 readily transmissible from animal to animal. 



The lesions are pulmonary hepatization with a marked interstitial 

 exudation and usually a purulent pleurisy. The symptoms consist 

 primarily of respiratory disturbance and a rise of temperature. 



All medicinal treatment that has been attempted has been of no 

 value. It is probable that an autogenous bacterin would be useful, 

 particularly as a preventive agent. Quarantine and the rigid enforce- 

 ment of sanitary regulations have been found serviceable in check- 

 ing the spread of the disease. 



Septic or Gangrenous Pneumonia 



Septic pneumonia is relatively common in swine. It has occurred 

 enzootically in swine affected primarily with forage poisoning asso- 

 ciated with pharyngeal paralysis. Sometimes it is a sequel to croupous 

 pneumonia. 



Etiology. — The usual cause of septic pneumonia is the introduc- 

 tion of foreign substances into the lung. In cases of pharyngeal 

 paralysis food escapes into the air tube. Drenching is another means 

 by which foreign substances are frequently introduced into the lung. 

 Thrombic obstruction of vessels supplying an area affected with 

 croupous pneumonia favors the action of saprophytic bacteria, and 

 hence putrefaction and the production of septic pneumonia. Ab- 

 scesses sometimes become infected with putrefying organisms and 

 produce septic pneumonia. The Bacillus necrophorns is active in 

 the production of necrosis and putrefaction in the lung. 



Lesions. — Necrotic centers are most frequently found in the de- 

 pendent and anterior part of the lung. The foci vary in size from 

 that of a pea to a baseball, and may be few or many. They appear 

 dirty brown, red, or dirty white in color. "When incised they are 

 found to be soft, the content being semifluid in the early stages but 

 later of a cheesy consistency. The surrounding lung tissue will be 

 inflamed. In the beginning, an infiltration circumscribes the lesions, 



