J our 11 al of Agrictilture. 



[8 June, 1907. 



l)evond them the degree of unsoundness mav be considered slight. But 

 when, in addition there is an exostosis or outgrown enlargement of bone in 

 anv direction the unsoundness is unquestionable. Such outgrowth of bone 

 extending from the lateral cartilages mav cause a bulging of the wall of 

 the hoof giving it an uns\ mmetrical ai)pe,arance when held up and examined 

 from behind. (See P'ig. 47.) 



Hereditary predisposition to sidebones is fully pro\-en ; and, so long 

 as their presence in brood mares and entires is not regarded with disfavour 

 1)\ tlie manafrement of live stock shows, the stead\ increase in the number 



tig. 48. Pedal boae (normal) with 

 lateral cartilages removed. (After 

 Haves.) 



i'"ig. 4(). Slight sidebones. 

 Haves.) 



(After 



of animals affected, which has been noticeable of late years in Australian 

 draught stock, will be maintained and most likely accentuated. 



Causes. — Concussion bv putting the lateral cartilages continuously on 

 the strain is likelv to be one of the causes of sidebone. but that it is not 

 the principal cause is evidenced bv the fact that horses in which the con- 

 cussive shock is the greatest and most frequent — trotters, roadsters and 

 gallopers — do not contract sidebones so readily as those which work at a 

 more moderate pace. 



Fig. 1^0. SidelxMie on one side onl\-, 

 (After Haves.) 



t'ig. 51. Typical 

 Haves.) 



lebones 



(After 



The principal cause would seem to be in the method of shoeing adopted 

 for cart-horses. These are practically the only horses that are shod with 

 calkins or high heels. One effect is that the frog is raised from the ground 

 and the downward pressure ujxju it, instead of being relieved by the con- 

 tact of the frog widi the ground, is exerted on the plantar cushion and 



