222 CHAPTER 22. 



there will be in most cases a dropsical swelling beween the fore-legs 

 under the sternimi, and the ridge along the abdomen will become more 

 and more distinct, and a straw-coloured serous discharge will be seen 

 from time to time to trickle from the nostrils. The expiration also will 

 be more markedly performed by a double action, i. e. the abdominal 

 muscles will be brought into play to assist in the expiration of the air. 

 As the weakness increases, the hair of the mane and tail will become 

 very loose, and may be easily detached. 



All sound of the percolation of the air necessarily ceases below the 

 point to which the serum or water has risen. In some cases the distended 

 vessels continue to pour out serum, until it has risen in the pleural cavi- 

 ties to such an extent as to cause death from suffocation. The water may 

 indeed be drawn off through a tube inserted into the chest, and temporary 

 relief will be gained ; but in most cases it quickly re-forms. But in other 

 cases, where the strength has been maintained, permanent relief may 

 sometimes be gained by tapping. 



All cases of effusion do not however terminate thus unfavorably. The 

 effusion may be only slight, and in such cases the lower part only of the 

 lungs is pressed upon, whilst sufficient remains for respiration. Natiu-e 

 then by means of the absorbents and blood-vessels takes up the whole or 

 part of the effusion. Any consolidated deposit that may remain, will 

 necessarily more or less impede the freedom of respiration. 



The degree in which Nature takes up the effusion, is principally 

 dependent on the tone of the vital powers after the acute attack has 

 passed away. If those powers have been weakened by depletive treat- 

 ment, by blisters and such-like remedies, or by neglect, Nature may pro- 

 bably be unable to take up the deposit. But if on the other hand by 

 judicious management, good nursing, attention to the appetite, and by 

 the absence of violent remedies those powers have been husbanded and 

 assisted, there is reason to hope that Nature may absorb all the effusion 

 and deposit. In these cases however, her powers will require to be 

 assisted by very careful and well-directed after-treatment. 



446. Exudation and organisation of Lymph, , Adhesion, &c. 



If the attack terminates in Exudation, the Lymph may be deposited 

 either between the lungs and the sides of the cavity of the chest, or in 

 the lungs, or it may affect both parts. Lj-mph as previously stated, is 

 adhesive in its nature, and has a marked tendency to become consolidated 

 and organised. 



In virtue of this property if, as in pleuritis, it is deposited between 

 the pleura of the lungs and the pleura of the ribs, it has, when suffered 

 to remain, a tendency to cause the one part to adhere to the other. This 

 result is known as Adhesion. If the adhesion of the lungs to the ribs 

 affects a large surface, their free motion and expansion is necessarily 

 interfered with, and the horse must ever after be unsound in wind and 

 unfit for fast work. 



If as in pure pneumonia the lymph is exuded into the lungs, it will, if 



