BONE-SPAVIN. 137 



the bone, and what is termed bone-spavin. It is a disease 

 of the inner splint-bone, and serious in its nature and 

 effects. 



The true nature and causes which induce bone-spavin 

 cannot be properly understood without a thorough know- 

 ledge of the hock-joint, which we have represented on plate 

 10, fig. 8. In this figure the shank-bone is represented at h 

 and the two small bones behind at g are the splint-bones ; 

 these support the lower layer of the bones of the hock 

 The cube-bone, /, rest chiefly on the shank-bone, and in a 

 slight measure on the outer splint-bone. The middle 

 wedge-bone, e, rests entirely upon the shank-bone, and the 

 smaller wedge-bone rests in a slight degree on tlie shank- 

 bone, but its chief support is on the inner splint-bone. 

 From this arrangement the splint-bones support a very 

 unequal degree of weight and concussion. The inner one 

 is placed more under the body, and consequently nearer the 

 centre of gravity, and besides nearly the entire weight and 

 concussion is communicated to the little wedge-bone. Hence 

 it is that during any violent action of this joint either in 

 leaping, galloping, or under the pressure of a heavy draught, 

 the inner splint-bone or its ligaments are injured. This is 

 mere especially the case with young horses before their 

 joints have 1 ecome firmly consolidated. 



The shoeing blacksmith or farrier too often is the cause 

 of inducing and increasing this complaint, by improper 

 treatra -nt of the feet. An erroneous notion has too long 

 prevailed among smiths that cutting and wounds of the feet 

 inflicted by the one foot treading upon the other can be 

 prevented by adding a calkin on the outer heel of the shoe, 

 which consists in the extremity of the shoe being bent, 

 elevating the outer heel considerably above the ground, and 

 thus the ligaments of the joints are subjected to an unequal 



