252 DISEASES OF BONE. 



do not cause the same degree of lameness as when the front is 

 involved." 



I have often observed in the lameness of ringbone, that the horse 

 lifts his foot off the ground in a peculiarly stiff manner, evidently, 

 with the object of trying to bend the pastern joints as little as 

 possible. 



Ringbone must not be confounded mth sidebone (p. 276), which 

 is ossification of the lateral cartilages of the foot. 



TREAT'ME(NT. — Although, to avoid a blemish, we may be 

 tempted to try the effect of a biniodide of mercury blister in pre- 

 ference to the hot iron ; it is no doubt the wisest policy in the 

 long run to puncture fire deeply, as in spavin (p. 259), the moment 

 ringbone manifests its presence ; because, if we delay, enough bony 

 material may be thrown out, in a short time, to permanently de- 

 stroy the free action of the aft'ected joint. The prompt use of the 

 iron (taking care not to open a joint) is the best means to arrest 

 the diseased action, and to cause the absorption of the bony mate- 

 rial which has already been deposited. If the horse goes on his 

 heel, use a thin rocker shoe (p. 197); if on his toe, employ a 

 high-heeled shoe. 



The operation of neurotomy is specially indicated in chronic 

 cases of lameness from ringbone. It not unfrequently stimulates 

 the absorption of the bony deposit. 



Bone Spavin. 



DEFINITION AND ANATOMY.— A bone spavin is a bony en- 

 largement which, as a result of disease, forms on the inside and 

 lower part of the hook (Figs. 93, 96 and 97). As a rule, the 

 term spavin is used as referring to bone spavin, except when " bog 

 spavin " is specially mentioned. 



In the hock (Figs. 9'8, 129, and 130) we have the true hock joint formed 

 by the astragalus and tibia, which serves for the bending and straightening of 

 the leg ; and to aid in the adjustment of weight during movement, there 

 are six or seven (according as the middle cuneiform consists of one or two 

 parts) small bones placed t)etween the cannon bone and astragalus, so as to 

 form joints possessed of a certain amount of gliding motion. 



Viewed from the front (Fig. 129), we see that the a&iTi^agalus rests on the 

 large cuneiform bone ; the large cuneiform, on the middle cuneiform ; and the 

 middle cuneiform, on the cannon Lone. On the inner side (Fig. U8) the small 

 cuneiform rests on the small inner splint bone and also on the cannon bone, 

 and affords support to the large cuneiform. On the outer side of the hock, 

 the cuboid bone rests on the cannon bone, stands alongside the large and 

 middle cuneiform bones, and has a side bearing against the outer splint bone, 

 the top of which is free from downward pressure. 



NATURI^: OF THE DISEASE.— According to Gotti and Bayer, spavin is 

 a chronic ostitis (inflammation of bone) which begins in the scaphoid, large 



