LAMENESS AND DISEASES, ETC. 



159 



weaken them at both sides of the commissures, as thin as safety 

 will permit ; keep pressure off the toe. In shoeing for drafting 

 purposes, toe and heel calkins will be required. In such cases, 

 have them low, and of the same height, that the foot may be 

 l^ept as close to the ground as possible, and the animal will 

 travel with more ease and safety. Let the shoes be adjusted in 

 a manner so as to fit the wall ; and to avoid the possibility of 

 cramping the foot, use small nails, with the nail holes straight 

 punched and driving so as to take a low, short, thick hold. Re- 

 set the shoes every three or four weeks. 



The horse's hoof, as described 

 in Chap. Ill, is so constructed that 

 any exertion may be best carried 

 on by a given elasticity from the 

 center of the toe, as the fulcrum 

 of a reciprocating motion or 

 spring around each side to the 

 heels. Should the natural con- 

 ditions of the foot be altered, 

 however, by being deprived of 

 sufficient moisture to preserve in 

 it that degree of combined tough- 

 ness and flexibility, the foot loses 

 its power to yield to pressure and 

 return, and when force sufficient 

 to overcome its resistance is ex- 

 erted, the hoof, no longer capable of springing to it, suddenly 

 gives way by splitting. 



This breakage occurs wherever the strain is the greatest — 

 at either of the sides from the quarters to the heel, or directly 

 through the middle of the hoof in front. 



The condition generally present, then, in the splitting of 

 the horny hoof, is a hard, dry, brittleness, and this may arise in 



Fig. 57. front view of the hoof 

 properly dressed for toe crack. 



