170 SWINE -PRACTICE 



PLEURISY 



Pleurisj^ is inflammation of the pleura and may be serous, fibrin- 

 ous, hemorrhagic, or purulent; acute or chronic. It is not a com- 

 mon condition among swine, at least in so far as the clinical recog- 

 nition of it is concerned. 



Acute Pleurisy 



Etiology. — Acute pleurisy is practically always the result of infec- 

 tion, although there are many predisposing factors that are active 

 in diminishing resistance and thus increasing the possibility of suc- 

 cessful infection. The causative organisms may gain entrance to 

 the pleura from the lungs through puncture wounds, through the 

 blood, and through the lymph. 



Lesions. — The pleura becomes hyperemic, tumefied, and dry. This 

 stage is succeeded by an outpouring of a serous, fibrinous, or hemor- 

 rhagic .exudate upon the pleural surface. Should the disease be due 

 to the activity of pyogenic organisms the exudate will soon become 

 purulent, and the future changes depend upon the nature of the 

 exudate. Serous exudate may accumulate in quantities in the pleural 

 cavity, and remain fluid although it may contain flakes of coagula. 

 The fibrinous and hemorrhagic exudates coagulate early and produce 

 greater or less adhesion of the visceral and parietal pleura. The 

 hemorrhagic exudate is characterized by the presence of quantities 

 of hemoglobin, which gives to it a red or blood color. 



Chronic Pleurisy 



Chronic pleurisy is characterized by the formation of varying 

 quantities of fibrous tissue which produce permanent adhesions of 

 the two layers of the pleura. There may also be considerable quan- 

 tities of a fluid (serous) exudate in the pleural cavity, and there 

 may be abscess formation, the pus being circumscribed by a definite 

 capsule. 



Symptoms. — ^Difficult breathing, each effort being accompanied by 

 a grunt, and sensitiveness of the thorax, characterize pleurisy. In 

 the acute cases there is inappetence, high temperature, and usually 

 constipation. Chronic cases frequently show little evidence of dis- 

 turbance. 



The acute type has a relatively short course, terminating in recov- 



