CHRONIC PLEURISY IN THE HORSE. 



207 



which only appear to be suffering from broken wind. Although in 

 practice these cases are seldom surgically treated, operation is justi- 

 fiable and necessary, as large pleural exudates may cause sudden death 

 by asphyxia. 



A colleague recently described to me a case of pleurisy following 

 pneumonia, in which the horse died in this way during the fifth week. 

 Having recognised how abundant was the exudate, he had thought of 

 tapping the chest ; but as the breathing did not appear alarming he 

 postponed operation until next day. The patient died during the 

 night. 



We may therefore lay down as a general rule that thoracentesis is 

 indicated whenever exudate is abundant. When it approaches the 

 middle line of the chest any temporising is dangerous, and operation 

 should at once be performed. 



The operation dates from the earliest historical period. In the case 

 of man it was performed by the Cnidians and the doctors of Cos. At 

 that time it was usual to incise the thoracic wall through an inter- 

 costal space, or to trephine a rib. The " hippiatres," predecessors of 

 the first veterinary practitioners, applied this treatment to the horse, 

 Lafosse indeed going so far as to declare that pleurisy could only be 

 cured by operation. Following them, some veterinary surgeons, during 

 the last and commencement of the present centuries, opened the pleura 

 by passing the point of a knife through an intercostal space. Thus 

 performed, operation produced immediate relief, but was too often 

 followed by infection of the pleura and passage of air into the thorax, 

 which almost always proved fatal. 



The first improvement consisted in substituting a trocar for the bis- 

 toury. Even Lafosse, in his Didionnaire d'Hippiatriqiie, gives a short 

 description of thoracentesis by means of the trocar. He recommends 

 passing the instrument between the lower portions of the seventh and 

 eighth ribs, opposite the costal cartilages, drawing off about half the 

 contained fiuid, and afterwards injecting slightly stimulating liquids 

 (liquides legerement vulneraires). He adds that the treatment is 

 " almost always certain " when the condition is of inflammatory 

 origin. 



For a long time the trocars used were too large ; complications 

 were very frequent and success rare. The operation had almost been 

 abandoned when it was rehabilitated by St. Cyr, who showed the good 

 results obtained by using a fine trocar. To prevent air entering the 

 chest Reybard suggested providing the cannula with a short tube of 

 goldbeater's skin, which allowed liquid to escape but prevented air 

 entering, the thin walls collapsing and closing the orifice when pres- 



