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 b 
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 the 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 become firmly consolidated. 
The shoeing blacksmith or farrier too often is the cause 
of inducing and increasing this complaint, by improper 
treatment 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 
