Course. Diagnosis. 151 



and soon thready. Chills and sweats come on from time to 

 time. There is great prostration and dullness of the sensorium, 

 the appetite is suppressed and profuse diarrhea not uncom- 

 monly comes on toward the end of the disease. 



Pleurisy frequently develops during the course of the dis- 

 ease; pneumothorax only exceptionally. Pulmonary hem- 

 orrhage from the rupture of a blood vessel by coughing or by 

 ulcerative processes of the vessel walls is rare. 



Course. If pulmonary gangrene follows upon some form of 

 pneumonia, it is preceded by the symptoms of this disease. If 

 gangrene occurs in the course of croupous pneumonia, 

 it usually occurs toward the terminal stage of hepa- 

 tization; the non-appearance of improvement or resolu- 

 tion, or a new elevation of the temperature which had 

 been falling, then point to an aggravation of the con- 

 dition. It is also possible that the symptoms of pul- 

 monary gangrene become manifest only after the beginning 

 of the stage of resolution ; a putrid inflammation of parts situ- 

 ated more centrally may at first not become manifest and may 

 only be suspected after the fetid odor of the exhaled air and of 

 the nasal discharge have been observed. In all cases, however, 

 after once being established, the gangrene progresses rapidly 

 to a fatal termination, and the animals die between the second 

 and fourth, or in any event before the end of the eighth day. 

 Pulmonary gangrene arising after other diseases than croupous 

 pneumonia, usually takes a similar course, except that some- 

 times weeks may elapse before a more considerable portion of 

 the lung has become affected. The symptoms are then at first 

 mild and only gradually increase in severity. A gangrenous 

 pulmonary focus may, in exceptional cases, become encapsu- 

 lated and recovery take place. 



Diagnosis. The only pathognomonic sign of pulmonary 

 gangrene is the presence of shreds of pulmonary tissue or of 

 elastic fibers in alveolar arrangement found in "the nasal dis- 

 charge or in the sputum expelled by coughing. Without the 

 detection of these elements, the diagnosis depends upon the pe- 

 culiar smell and upon the detection of signs pointing to cavity 

 formation in the lung. In other cases, a diagnosis can be made 

 only with some degree of probability; it becomes, however, 

 fairly certain as soon as the peculiar disagreeable smell becomes 

 manifest in the course of acute pneumonia, or if the symptoms 

 of pneumonia come on after a disease wdiich points to the aspira- 

 tion of particles of food, masses of secretion, etc. Signs of sep- 

 sis are also of importance and always accompany pulmonary 

 gangrene of any extent. 



The disease might be confounded most easily with putrid 

 bronchial catarrh ; if primary, this does not lead to any consid- 



