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neglected in this stage of the disease the symptoms become 

 greatly aggravated ; the serum of the blood exudes through 

 the coats of the blood vessels, and permanent injury is the 

 result. The doctrine of exudation may be briefly stated 

 thus : a quantity of fluid in porous vessels being forced upon 

 a centre whose condition allows little or none of it to be 

 transmitted, an effusion must result, through the distended 

 coats of the vessels. 



When the lungs of an animal are thus subjected to inflam- 

 matory action, as in pneumonia, this exudation of the serum 

 of the blood is poured into the air cells, and there solidifies, 

 which makes the hope of recovery in bad cases almost 

 impossible. When the patient is seen and treated in time, 

 that is, while there is only congestion of the lungs, no per- 

 manent damage has been done. When the cells are filled 

 with this exuded material the lung is said to be hepatized, 

 or a liver-like tissue. The healthy lungs float on water ; in 

 the latter state they sink. 



Besides these symptoms there are others. If we apply 

 the ear behind the shoulder, instead of the natural respira- 

 tory murmur of healthy lungs, we shall hear a fine crackling 

 crepitation, succeeded by a coarse, mucus rale, as the dis- 

 ease progresses. When we tap the spaces between the ribs 

 there comes back a dull, dead sound, which shows that the 

 air cells are filled with the exudation. Dullness on percus- 

 sion is the evidence of the solidifying of the cellular tissue 

 of the lungs from the effects of the inflammation. 



In some rare examples the inflammation leaves the lungs 

 and attacks the laminae of the foot, producing founder or 

 laminitis. 



Treatment. — The subject of treatment in this disorder 

 is highly important. Improper remedies will do immense 

 mischief, and in teaching others what plan to follow a man 

 must know what he is talking about. In the late epizootic 

 we had in some patients pneumonia associated with in- 

 fluenza, and many died from the effects of proper remedies 



