SYMPTOMS. 535 



The pulse becomes increased in frequency and of smaller 

 volume, probably eighty to ninety per minute, or irregular; 

 the respirations are laboured, or dyspnoea may be distressing ; 

 the flanks heave excessively, and there is a peculiar lifting of 

 the loins. The animal generally stands with his head pro- 

 truded, the nostrils flapping synchronously with the heaving 

 flanks, while dropsical swellings, appearing first at the inferior 

 part of the chest, extend along the floor of the abdomen, and 

 may ultimately invade the limbs, which usually remain of 

 deathly coldness. That the dyspnoea and imperfectly per- 

 formed respiratory function are owing to compression of lung- 

 structure from the presence in the pleural sac of adventitious 

 fluid, we are satisfied by auscultation and percussion. 



Although the symptoms of acute pleurisy are tolerably 

 attractive and diagnostic, there is no doubt that a latent morbid 

 state of the pleural membrane not unfrequently exists, and 

 proceeds to fatal results without giving much or any indication 

 of structural alterations during life. 



The knowledge of these facts ought to warn us that in all 

 cases where indisposition proceeds from rather inappreciable 

 causes, but where, from certain associations, suspicion may be 

 directed to the chest, that the conditions of this cavity are not 

 to be fully comprehended by the observation of rational 

 symptoms alone, that nothing but a careful physical examina- 

 tion can satisfy us of the existence of very important struc- 

 tural changes occurring there. 



Course and Terminations. — The period over which an attack 

 of pleurisy may extend and yet terminate in recovery is very 

 varied. The milder cases, where the inflammatory action is 

 not severe, the surrounding influences favourable, and the 

 animal's previous health good, may give evidence of recovery 

 in a few days. The small amount of effusion has, on the 

 suspension of the inflammation, been rapidl}^ removed, and 

 convalescence established Avithin a week from the occurrence 

 of the attack. 



In others, again, the action may have been of a more violent 

 character, the animal may have been possessed of less constitu- 

 tional vigour, or the surroimdings mayjhave been decidedly de- 

 pressing. In such the exudation is more likely to be copious, 

 whether of the form of plastic organizable material or simply 



