ACTION OF THE LIMBS. 



185 



From the foregoing may be deduced two principles for the 

 practice of shoeing, viz. : — (1) The normal form of the hoof 

 should be preserved or restored, hiot with due regard to the 

 conformation of the limhs and to the animal's action. (2) The 

 functions of the various parts of the foot must be aroused to 

 full activity. 



In regard to the first, the normal form of the foot is under- 

 stood to be that which would result were the animal unshod 



Fig. 173. 



Fig. 174. 



Fig. 175. 



and in a state of nature. It need scarcely be said that, given 

 this normal form, the balance of the limb must not be dis- 

 turbed by inequalities of thickness in different parts of the 

 shoe, but that the hoof surface of the shoe must lie in a hori- 

 zontal plane. 



Eespecting the second, it is indispensable that the frog and 

 sole come in contact with the ground. One must not forget 

 that expansion of the foot depends entirely on the action of the 

 plantar cushion, and therefore primarily on frog-pressure. 



4. Form of the Hoof. 



The normal front hoof (lig. 176) shows little difference in 

 the direction and thickness of its inner and outer walls. The 

 outer is slightly thicker and rather less upright than the inner 



