THE RESPIRATORY APPARATUS 49 



Whistling. — Whistling is mostly due to a 

 thickened condition of the mucous membrane 

 lining the air-passages, and a consequent narrow- 

 ing of these passages. Whistling is an unsound- 

 ness, but the horse is capable of more fast work 

 than a roarer. 



Grunting. — This is the name given to the 

 noise that is at times made by a horse on being 

 suddenly and unexpectedly struck at either by 

 the fist or with a stick ; an animal making such 

 a noise is termed a ' grunter.' The making of 

 the noise may be associated with disease of the 

 throat, or to some abnormal state of the chest ; 

 or, on the other hand, it may be caused, and 

 frequently is, by the horse being fat and out 

 of condition. Many a horse that grunts is 

 perfectly sound in his wind, and many a horse 

 that is a bad roarer will not grunt on being tested. 

 Grunting points to a probable unsoundness of the 

 wind, and when a horse makes this noise he 

 should be most carefully examined in other 

 respects for soundness of wind. 



Grunting is considered by many as an unsound- 

 ness, but, in my opinion, unjustly so, for if on 



