EOAEING. 381 



On the other hand, I have known instances, in Egypt and India, 

 of horses becoming roarers when .liberally fed on ordinary chopped 

 straw, the ends of which would probably have an irritating effect 

 on the mucous membrane of the mouth, gullet and stomach. The 

 animals in question were either English horses or Australian 

 horses descended from English parents, and therefore more or 

 less predisposed to this complaint. As I could find no cases of 

 roaring produced in this manner among Egyptian, East Indian, 

 and Arab horses which were fed under similar conditions, I 

 conclude that this manner of feeding can produce the disease 

 only in conjunction with a predisposing influence, such as that 

 of heredity. Many experienced stablemen in England consider 

 that hay given in large quantities is a well-marked cause of 

 roaring, especially if it contains a considerable proportion of 

 rye grass, which is rich in woody fibre. The proportion of 

 woody fibre in hay is much higher if the grass is cut late, than 

 if it is harvested early in the season, say, in the beginning of 

 June; and also varies according to the amount of fermentation 

 that takes place during the process of drying. Heavy cart-horses 

 in Scotland and in the North of England, many of which are given 

 large quantities of straw to eat, are almost as subject to roaring 

 as are thorough-breds. Here, the fact that they are of great size 

 ..(p. 383) has a strong predisposing influence. 



Experience justifies the remark that, other conditions being 

 equal, horses fed on green grass are not so liable to roaring as 

 those which are kept on hay or straw, especially if it is chopped. 

 It is instructive to note that if straw is chopped so fine as to allow 

 it to be readily swallowed without being well masticated, it is 

 much more liable to cause indigestion than if it is cut at a length 

 of, say, four or five inches. 



PREDISPOSING CAUSES OF PARALYTIC ROARING.— 1. A 

 cold, damp climate is imdoubtedly the chief predisposing cause in 

 this disease, evidently by its influence in producing diseases of the 

 organs of breathing. In fact, the liability to contract roaring in a 

 country, other conditions being equal, is directly proportionate to 

 the tendency of horses in that climate to catch colds and coughs. 

 No country, however, is absolutely free from this disease, which is 

 common in the cold, damp cliinate of Great Britain and Ireland, 

 but is almost unknown in the warm climates of India, Egypt, 

 Syria, Arabia, Persia, South Africa and South America. During 

 an eighteen years' residence in India, I found only two or three 

 cases of roaring among the many thousands of Arab horses met 

 with, and about the same number in Indian-bred horses. It is 



