CAUSES OF UNSOUNDNESS. 131 



and broken-winded at night. But this seldom 

 holds good, because veterinarians are universally of 

 one opinion as to the gradual development of this 

 affection. Although the true pathological nature of 

 the malady is not understood, the changes usually 

 observable post mortem, in connection with the 

 lungs and stomach, show that broken wind 

 is gradual in its development. The dilatation of 

 the air vesicles, together with the rupture of many 

 of these, and the thinning of the walls of the stomach, 

 so often present, are clearly indicative that the 

 disease occupies weeks, or months in its develop- 

 ment. One cause of broken wind is feeding upon 

 dusty hay, and driving the animal immediately after 

 feeding ; this shows the advisability for not working 

 a horse for at least an hour after it has been fed 

 and watered. A broken-winded horse may con- 

 tinue to do its work fairly well, but it is necessary 

 to pay particular attention to its feeding, avoiding 

 bulky food, dry food, dusty fodder, or food of 



inferior quality. 



Grunting. 



Almost every horseman is familiar with this term, 

 and dealers usually look upon it as evidence that 

 the animal is not sound in its wind. But veterinary 

 surgeons know differently to this, because some 



9* 



