114 



"prehension of the subject that will sufiSce for the purpose of being bet- 

 ter able to lucate the various diseases and appreciate the mechanism of 

 the respiratory organs in their relations to each other. 



CONGESTION OF THE LUNGS. 



Inflammation of the lungs is always preceded by congestion, or, to 

 make it plainer, congestion may be considered as the first stage of in- 

 flammation. Congestion is essentially an excess of blootl in the vessels 

 of the parts affected. Congestion of the lungs in the horse, when it 

 exists as an independent affection, is generally caused by overexertion 

 when the animal is not in a fit condition to undergo more than moder- 

 ate exercise. 



The methods practiced by the trainers of running and trotting horses 

 will give an idea of what is termed " putting a horse in condition" to 

 stand severe exertion. The animal at first gets walking exercises, then 

 after some time he is made to go faster and farther each day; the 

 amount of work is daily increased until the horse is said to be " in condi- 

 tion." An animal so prepared runs no risk of being afiFected with con- 

 gestion of the lungs if he is otherwise healthy. On the other hand, if 

 the horse is kept in the stable for the purpose of laying on fat or for 

 want of something to do, the muscular system becomes soft, and the 

 horse is not in condition to stand the severe exertion of going fast or 

 far, no matter how healthy he may be in other respects. If such a 

 horse be given a hard ride or drive, he may start off in high spirits, 

 but soon becomes exhausted, and if he is pushed he will slacken his 

 pace, show a desire to stop, and may stagger or even fall. Examina- 

 tion will show the nostrils dilated, the flanks heaving, the countenance 

 haggard, and every other appearance of sufibcation. How was this 

 brought about! The heart and muscles were not accustomed to the 

 sudden and severe strain put upon them; the heart became unable to 

 perform its work; the blood accumulated in the vessels of the lungs, 

 which eventually became engorged with the stagnated blood, consti- 

 tuting congestion of the lungs. 



The animal, after having undergone severe exertion, may not exhibit 

 any alarming symptoms until returned to the stable; then he will be 

 noticed standing with his head down, legs spread out, the eyes wildly 

 staring or dull and sunken. The breathing is very rapid and almost 

 gasping, the body is covered with perspiration in most cases, which, 

 however, may soon evaporate, leaving the surface of the body and the 

 legs and ears cold; the breathing is both abdominal and thoracic; the 

 chest rises and falls and the flanks are powerfully brought into action. 

 If the pulse can be felt at all it will be found beating very frequently, 

 one hundred or more to a minute. The heart may be felt tumultuously 

 thumping if the hand is placed against the chest behind the left elbow, 

 or it may be scarcely perceptible. The animal may tremble all over the 

 body. If the ear is placed against the side of the chest a loud murmur 

 will be heard, and perhaps a fine crackling sound. 



