CHRONIC PLEURISY IN THE HORSE. 205 



liquid sound ma}- be heard — a kind of splashing produced by the exudate 

 striking against bands of fibrous tissue below the level of its surface (if 

 the expression be permissible). 



The phenomena discovered on auscultation and percussion almost 

 always exist on both sides of the chest and to a similar height. Certain 

 cases, however, prove that exudate may be confined to one pleural sac, 

 and the fact that the physical signs are unilateral does not at once 

 exclude the diagnosis of pleuris\'. 



As a rule the costal walls are not abn^ rmali}- sensitive except as a 

 result of repeated stimulating applications. In some patients the 

 lower part of the chest shows trifling oedematous swelling, and infiltra- 

 tion of the subcutaneous tissues may be detected by pressing with the 

 tips of the fingers o\er the intercostal spaces. 



Chronic pleurisy usually persists and becomes aggravated, slowly if 

 the patients are carefully nursed and fed, but rapidly if they are worked 

 and exposed to chills or inclement weather. The dyspnoea increases 

 in proportion to the increase of exudate. The cough, wasting, and 

 loss of strength become accentuated, the heart-sounds and pulse weaker 

 and weaker. When the increase of exudate is very slow signs of 

 general debility appear ; the limbs swell, and the animals finally die of 

 exhaustion. In the contrary case respiration soon becomes ver}- 

 painful, the animals remain standing with the limbs spread widely 

 apart, struggle for breath, and on falling die of asphyxia. 



Chronic pleuris}- in the horse ma}-, however, terminate in resolution. 

 In rare cases the exudate ceases to increase, and after an inter\al 

 gradually becomes re-absorbed. The general disturbance and special 

 S}-mptoms recede, appetite and strength return, respiration becomes 

 less frequent and difficult, the area of dulness diminishes, the bronchial 

 sounds disappear, and the ^•esicular murmur returns in the lower parts 

 of the chest. Recover}- is almost alwa}s incomplete, the respiratory 

 movements generall}- remaining irregular, and a little dr}- cough 

 resembling that of emphysema persisting. 



On post-mortem examination of horses which die of chronic 

 pleuris}- the pleura; contain a more or less abundant, clear, transparent, 

 or slightly yellowish serosity, with or without fibrous flocculi ; some- 

 times the exudate is purulent. The pleura is irregularly thickened, 

 whitish, rough with villous processes, and partial!}- co\-ered with 

 masses of fibrous deposit of all shapes and sizes ; sometimes the 

 pulmonar}- and costal or diaphragmatic pleurfe are adherent. If death 



