534 PLEURISY. 



ing. Accompanying these symptoms, or following close upon 

 their appearance, may be restlessness and exhibition of pain ; 

 this pain seems aggravated by breathing, the inspiratory part 

 of the act being cut short by coughing. A like exhibition of 

 distress is induced by causing the animal to move round, and 

 particularly so when the chest is manipulated or percussed. 



From the pecuharity in carrying out the inspiratory act by 

 the fixing of the ribs and special action of the abdominal 

 muscles, there is exhibited very early one of the most charac- 

 teristic symptoms of the disease, a depression or line of demar- 

 cation running from the floor of the thorax at the posterior 

 part of the sternum, in an oblique and upward direction, 

 backward to the anterior iliac spine, known as the pleuritic 

 or abdominal ridge. 



In the earlier stages the pulse, increased in frequency, is 

 concentrated in its impulse, hard and vibratory. The mucous 

 membranes are not altered much in colour, the mouth dry, 

 internal temperature elevated three or four degrees, while the 

 countenance is anxious-looking, expressive of pain, and the 

 expired air is less hot than in pneumonia. 



If at this time Ave apj^ly the ear to the chest we may be able 

 to hear the unnaturally dry membranes, the costal and pul- 

 monary pleura rubbing against each other, and may even, in 

 many instances, by placing the hand over the chest, feel the 

 same movement — the ' friction sensation.' At the same time 

 it will be found that the vesicular murmur is weak, from the 

 imperfect manner in which it is performed. Percussion, when 

 such can be carried out, which is not often, will give no appre- 

 ciable difference of resonance. 



Very shortly the sounds heard by auscultation cease, either 

 from return to health, the occurrence of adhesion between the 

 membranes, or the presence of fluid in the cavity. 



With the occurrence of eftusion the more active symptoms 

 of pyrexia and pain subside. The temperature may fall a 

 little, the pulse will be less jarring, and the appearance of the 

 pleuritic ridge less distinct. 



When the effusion is considerable, and the amount is little 

 influenced by the natural absorptive powers of the system, or 

 where the morbid activities still continue, the symptoms, 

 although altered, are more serious. 



