CHAPTER IV. 



PREDISPOSING CAUSES OP EOAEING . 



In the production of what I have termed, following the 

 example of French Veterinarians, "Chronic' Roaring," we 

 must not overlook the existence and the influence of pre- 

 disposing causes, as it is only by recognising and endea- 

 vouring to neutralize them that we can hope to prevent 

 its occurrence. These causes are numerous and various, 

 and some of them are more potent and obvious in their 

 influence than others; they may be considered in their 

 relation to : I. Climate ; 2. Heredity ; 3. Breed ; 4. Sex ; 

 5. Size ; 6. Age ; 7. Conformation ; 8. Management ; 9. Acci- 

 dental Causes. 



1. Climate. 



In treating of the prevalence of Roaring, in the preced- 

 ing chapter, there was much and strong evidence given in 

 favour of the influence of climate as a predisposing cause, 

 and it was remarked that horses in Western and Northern 

 countries are much more liable to it than those of Eastern 

 and Southern regions. Even in Europe this is evident, the 

 horses of Italy and Spain being very much less affected 

 than those of England, or Northern Germany and France. 

 Cold and damp climates appear to favour its production, 

 not only because they are inimical to the natural vigour of 

 horses, but also because the artiflcial conditions in which 

 they have to be maintained in order to protect them from 

 the deteriorating influences of climate, or to improve them, 

 are predisposing agencies in themselves, tending as they do, 



