362 LUNGS AND PLEURA. 



pleuritic souffle (a soft tubal souffle quite different from that of con- 

 tagious i)leuro-pneumonia) when pleural exudation is abundant. In 

 septic or su^jpurative pleurisy fever is higher, loss of appetite more 

 marked, wasting more rapid, and depression extreme, with, however, 

 identical local S3'mptoms. 



Diagnosis. The diagnosis of pleural exudation presents little diffi- 

 culty, because of the peculiar characters of the dulness and the pathogno- 

 monic indications obtained by auscultation. The exudation is usually 

 unilateral, the mediastinum being very resistant and not perforated 

 in the ox. 



By passing the needle of a Pravaz's syringe with antiseptic pre- 

 cautions through the intercostal space a little fluid may be drawn off 

 and the diagnosis formed, the form and nature of the pleurisy being 

 simultaneously established. The liquid extracted can be examined bac- 

 teriologically, and can be grown on nutritive media, or inoculated into 

 exi^erimental animals. 



The prognosis is grave, because in the ox pleurisy is very often of 

 a secondary character. The outlook varies, however, with the form of 

 the pleurisy and the nature and virulence of the infecting organism. 



Treatment. Treatment consists firstly in applying an energetic 

 vesicant like antimonial ointment or liquid cantharides blister ; in- 

 ternally diuretics such as soda bicarbonate, nitrate of potash, resin, 

 and decoctions of pellitory, dogs' grass, etc., may be given. If thought 

 desirable the chest may be tapped and the pleural cavity washed out 

 with an antiseptic solution. 



CHRONIC PLEURISY. 



Chronic pleurisy is frequent in aged animals, but usually assumes the 

 form of local adhesive pleurisy. The adhesions between the lung and 

 pleura are more or less extensive ; they result from verminous broncho- 

 pneumonia, echinococcosis, external injuries, etc. Clinically this form 

 is of no importance, and is almost impossible to diagnose. During 

 the development of pleural tuberculosis, on the contrary, adhesive dry 

 pleurisy is frequent, and sometimes becomes so well marked that almost 

 the whole of the opposing pleural surfaces may become united. 



PNEUMO'THORAX. 



The name pneumo-thorax is given to the condition produced by the 

 entrance of air or gas into one of the pleural cavities. 



The accident is usually produced by rupture of the parenchyma of 

 the lung and of the pleura, a rupture which produces a communication 

 between the alveoli or a bronchus and the corresponding pleural cavity. 



