150 DISEASES OF THE HORSE. 



On a road the clatter made by the horse's feet is 

 so great that it will drown, in many cases, the lesser 

 noise of roaring ; and it is not proper to examine their 

 expirations when they are pulled up, as many bad 

 roarers cease making a noise immediately they are 

 stopped. 



There is a rattling gurgling noise in the throat, 

 however, which must not be mistaken for roaring. 

 Many of the clearest winded horses will do it when very 

 passionate and excited, or when pulled severely with 

 a sharp bit. 



I have known horses rejected by veterinary surgeons 

 of limited experience, and others, for this cause, but I 

 have never known one of them turn roarers. The 

 usual causes of roaring are these : 



1. Thickening of the bronchial tubes. 



2. Paralysis of the left recurrent nerve and the 

 muscles amongst which it ramifies. 



3. Thickening of the tracheal tube, caused by inflam- 

 mation or abscesses. 



4. Exostosis of the cartilages. 



I have thought fit to name the usual causes of this 

 malady, not that the knowledge of them can in any 

 way tend to effectual treatment, but to show that the 

 causes of the disease are more or less occult during life ; 

 and, therefore, that when men undertake to cure this 

 or that case of roaring by such means as firing the 

 larynx, the use of blisters, caustic, &c, with doses of 

 strychnine, they undertake what they cannot perform, 

 and unjustifiably raise the hopes of the owner, which 



