2o6 CLINICAL VETERINARY MEDICINE AND SURdERY. 



results in consequence of a fresh acute attack, these organised new 

 membranes are covered with iibrinous or purulent exudate. 



Chronic pleurisy being sometimes curable, what are the best means 

 of treatment ? 



Internal medication is of little value. In the acute form bicarbonate 

 and salicylate of soda, given in the drinking-water, and pilocarpine or 

 arecoline administered subcutaneously appear useful, but are of little 

 value in the chronic stage. 



Laxatives and diuretics internally, together with rubefacients and 

 blisters applied to the walls of the chest, constitute the usual treat- 

 ment. 



Repeated mild blistering of both sides of the chest, as high as the line 

 of exudate, is sometimes successful. When recent pleurisy is in process 

 of becoming chronic these most probably act by favouring vascularisa- 

 tion of the new membrane, and thus multiplying the channels through 

 which absorption may occur. They are less effectual in old-standing 

 distinctly chronic pleurisy. In such cases they should be associated 

 with tapping the chest. Many cases are said to have been permanently 

 cured by this treatment. 



In addition to their questionable efficacy in chronic pleurisy blisters 

 entail serious disadvantages if tapping has afterwards to be performed. 

 The purulent dermatitis they produce renders it difficult to disinfect 

 the seat of operation, and exposes the patient to danger of pleural 

 infection. When the methods are combined the chest should first be 

 punctured, and if a repetition of the operation become necessary the 

 parts should be very carefully disinfected. 



Tapping the chest is unquestionably the most rational and efficacious 

 method of treating chronic pleurisy. 



As the two pleural sacs almost always communicate, puncture of one 

 side results in withdrawal of most of the contained liquid. If the 

 orifices in the posterior mediastinum are plugged (shown by the per- 

 sistence of exudate in the side removed from that of operation), both 

 sides must be tapped. 



In chronic as in acute pleurisy operation should be resorted to as 

 soon as breathing becomes distressed and exudate abundant. Very 

 generally the two conditions march together, dyspnoea being propor- 

 tional to the quantity of liquid in the thorax. Nevertheless exceptions 

 occur, pulmonary or cardiac disturbance sometimes rendering breathing 

 difficult even when the exudate is scanty. Conversely, cases occur 

 in which dN'spncea is trifling, while the pleuritic exudate is con- 

 siderable. You will see horses with double-sided abundant exudates. 



