92 ESSAYS ON HORSE SUBJECTS 



But what about his muscular tissue? It 

 apparently looks as bulky as ever. So it 

 is and possibly more so, but that it has be- 

 come impaired in muscular power can easily be 

 demonstrated by an hour's brisk work in the case 

 of a driving horse. He goes out full of life, and 

 possibly shows to the best advantage for a short 

 time, but soon begins to drop his head, go heavy 

 in hand, in fact to lag, loses his action, and very 

 likely forges. This demonstrates the fact that, 

 no matter how well a horse may seem nourished, 

 he cannot maintain his muscular tone and mus- 

 cular power without adequate work. 



The changes that take place in the muscles of 

 locomotion also take place in the muscular tissue 

 of other parts of the individual. The central 

 organ of the circulation, the heart, is a hollow 

 muscle, and the blood vessels have muscular fibres 

 in their coats. If a horse is insufficiently exer- 

 cised, the muscular tissue of the heart and blood 

 vessels becomes impaired in power, as that of the 

 muscles of locomotion does. If a horse in such con- 

 dition is abruptly put to brisk work, the circula- 

 tion is apt to show weakness, and there is danger 

 of congestive and inflammatory attacks. A horse 

 out of condition and lacking in muscular tone 

 will develop congestion of the lungs, from an 

 amount of exertion that would have no injurious 

 effect upon one in moderately good condition. 



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