596 DISEASES OF SWINE 



not as high as in pneumonia. The animal becomes dull, loses 

 appetite, and all desire to move about. When forced to rise from 

 the nest and move around, the sick hog moves very slowly and 

 stiffly, and is Hkely to show marked lameness in the front feet. 



Breathing in this case is very peculiar. There is practically no 

 movement of the ribs and muscles of the chest, and the breathing 

 is done entirely with the muscles of the flank. The breathing is of 

 a short, jerky character and quite rapid. If any effort is made to 

 examine the animal we find marked signs of pain in the side. An 

 effort to press over the ribs of the affected side will cause the animal 

 to flinch and grunt or even squeal with pain. This is especially 

 noticeable early in the disease. 



A little later in the course of the disease a fluid is poured out 

 into the cavity of the chest between the layers of the pleura, and 

 then the pain becomes less marked and the muscles of the chest 

 are again used in breathing. The pressure of the fluid upon the 

 lungs makes breathing very difficult, however, and the animal 

 produces a grunting sound at each breath. As the disease clears 

 up the pain again returns, the ribs are again held rigid, and the 

 jerky abdominal breathing is seen. 



During the early stages of pleurisy, if the ear be placed over the 

 ribs, a very peculiar and characteristic noise is often heard. This is a 

 grating or rubbing sound, produced by the grating of the inflamed 

 surfaces of the pleura upon each other. It sounds very much Uke 

 rubbing two pieces of sand-paper together, and is a very important 

 point in the diagnosis of the condition. When the fluid is poured 

 into the pleural sac this grating sound disappears, and we have it 

 replaced by an absolute absence of sound. There may be some 

 bulging of the spaces between the ribs at this time. Later in the 

 condition, when the fluid is absorbed, the grating sound may return. 



In the chronic form of pleurisy the animal becomes run down, 

 loses flesh and strength, and often will be found to remain lying in 

 the litter and refuses to get up and move about. If forced to get 

 up and walk the animal is found to be very weak. In some cases 

 the disease spreads to the heart or lungs and results in death. 



Anatomic Changes.— The changes which occur in appearance 

 of the pleura in the course of this disease are very interesting, and 

 give us a clear understanding of the variation which takes place in 



