354 LUNGS AND PLEURA. 



can be early diagnosed before intense and continued fever has set in, 

 and ^Yhen the animal's condition is good, it is often preferable to 

 slaughter the patient. 



INFECTIOUS BRONCHO -PNEUMONIA. 



The ox's lung is lial)le to so many and such extremely varied 

 diseases that it seems desirable to add to the above descriptions 

 some remarks on infectious broncho-pneumonia of external or in- 

 ternal origin. 



Anatomically these forms of broncho-pneumonia are characterised 

 by the occurrence of " islands " of pulmonary hepatisation, more rarely 

 by extensive (massive) hepatisation ; in all cases the hepatisation is 

 irregular, and in no way resembles that of simple pneumonia. 



Causation. The internal causes are numerous and varied. They 

 are due to primary infection of an organ whence arises a general infec- 

 tion, sometimes even true septicaemia. Some form of broncho- pneu- 

 monia, such as simple broncho-pneumonia, purulent broncho-pneu- 

 monia, gangrenous broncho-pneumonia, etc., then follows as a compli- 

 cation. These l^roncho-pneumonias are therefore only manifestations 

 of purulent infection or septicaemia. They frequently follow post- 

 partum infections, vaginitis, metritis, and suppurative mammitis. 



Symptoms. The general symptoms first attract attention, and are 

 extremely acute. They comprise high fever, loss of appetite, cessation 

 of rumination and of milk secretion, breathlessness, blowing, etc. — all 

 signs of grave and rapidly progressive infection. 



Sometimes at this period nothing more than the primary lesion, such 

 as metritis or mammitis, can be detected. It may even happen that the 

 uterus seems little affected, and, despite the accelerated respiration, 

 neither partial nor complete dulness of the lung is discovered. 



Hepatisation only occurs some days afterwards, and with it irregular 

 partial dulness localised in the lower zones, disappearance of the respira- 

 tory murmur in the corresponding regions, exaggeration in the infected 

 regions, an expiratory sound which is barely perceptible or may be of a 

 blowing character, or, again, after several days may be transformed into 

 a tubal souffle. 



The cough then becomes frequent, generally difficult, paroxysmal, 

 feeble, and easily provoked. The appetite suffers, the patients seem 

 to prefer fluid nourishment and lose flesh very rapidly. 



[f the broncho-pneumonia is about to terminate in suppuration 

 or gangrene, "the respiration becomes sighing, the breath foetid, and 

 the cough is accompanied by a greyish muco-purulent or gangrenous 

 discharge. 



