THROAT AND LUNG DISEASES 235 



should be omitted — and after that the arsenic should be 

 resumed in the same manner in which it was left off. 

 Great harm may be done to the health of a horse either 

 by beginning abruptly or by leaving off abruptly a 

 powerful tonic like arsenic. 



If a horse is getting too much arsenic he will show 

 it by the very light yellow color of his dung. 



BROKEN WIND 



A wind-broken horse is one whose windpipe has 

 become thickened, so that he makes a roaring or 

 whistling sound when pulled or driven hard. 



It is usually caused by driving a horse too fast and 

 too far; or by making him pull too heavy a load, 

 especially after eating or drinking. There is no cure 

 for this trouble, but careful feeding will do something 

 to make it less severe. As in the case of a heavey 

 horse, the aim should be to give him food in a form 

 as little bulky as possible — to nourish him without 

 over-distending the stomach. (See the directions given 

 above as to feeding a horse suffering from heaves.) No 

 medicine or drugs of any kind can relieve the broken- 

 winded horse. Care should of course be taken not to 

 call upon him for any effort when his stomach is full. 



Some perfectly sound horses, especially if they are 

 soft and fat, will curve their necks in, when pulling 

 hard on the bit, and so shut off their own wind and 

 make a roaring sound as if they were broken-winded; 

 and it is not always easy to tell in such cases whether 

 there Is any real trouble with the air passage or not. 



A horse with heaves never breathes naturally even 



