Acute Sero-Fibrinous Pleurisy in the Horse. Pleuritis. 323 



This early fatality is, however, only seen in the worst cases. 

 In those about to terminate favorably, improvement is shown 

 usually about the fourth day. The lifting of the flanks and loins 

 becomes moderated, the ribs move more freely, the grunt ceases, 

 the pulse is fuller, softer and less frequent, and auscultation and 

 percussion show a steady decrease in the effusion. The loins be- 

 come sensitive to pinching, and chlorides appear in the urine. 

 Appetite meanwhile returns, the horse moves more freely, lies 

 down for a length of time in succession, and convalescence lasts 

 from two to three weeks. 



In the less fortunate cases structural changes more or less per- 

 manent, keep up symptoms of illness for a variable length of time. 

 Sometimes after the liquid effusion has been absorbed the lung re- 

 mains attached to the side of the chest by newly formed tissue (false 

 membrane) and while this is undergoing a drying and organizing 

 process, it gives rise to a leathery, creaking sound heard on aus- 

 cultation and easily mistaken for crepitation. Sometimes an ab- 

 scess forms on the surface of the pleura or in the newly organized 

 false membrane, and either bursts into the pleural sac (empyema) 

 where it serves to infect, and increase and sustain the irritation, 

 or it makes its way through the intercostal spaces and is discharged 

 externally. In this last case its advance toward the surface is 

 heralded by an extensive inflammatory infiltration and pasty 

 swelling much more tender to the touch than the dropsical swell- 

 ing already referred to. Another condition is that in which false 

 membranes of considerable thickness invest a lung and, following 

 the law of all fibrous structures in process of organization, they 

 contract and cause a compression and partial collapse of the con- 

 tained lung tissue. A flattening of the corresponding side of the 

 chest and a muffled and almost inaudible respiratory murmur is 

 the result of this condition. In some measure these symptoms 

 are present during convalescence in all cases of pleurisy since the 

 lung never expands to its full size till some time after apparent re- 

 covery, but it is only when the organ is invested with false mem- 

 brane that the symptoms are very apparent. 



In all such cases of prolonged pleurisy from protracted structural 

 change, there is continued illness without the violent symptoms 

 by which the acute form of the disease is manifested. The acute 

 suffering, the restlessness, the grunt, and even the catching 



