SHOEING, AND DISEASES AND INJURIES OF THE FOOT. 199 



The unpared sole and frog of the healthy foot need no 

 protection on any kind of soil. The flakes of loose horn on the 

 former serve a very useful purpose in retaining moisture, and 

 so keeping the solid horn beneath soft and elastic, while they 

 act as so many springs when the foot is placed on projecting 

 stones. The more the frog is exposed to wear, the larger 

 and sounder it grows, and the better it is for the foot and 

 limb. 



The fore-foot is of more importance, in the matter of 

 shoeing, than the hind one ; inasmuch as it has to support 

 much more weight, and is consequently more exposed to disease 

 and injury. 



The fore-foot, when well formed, is nearly, if not quite, 

 circular ; the hind-foot is somewhat oval, the frog smaller, and 

 the sole more concave. "When the hoof is shod the wall is not 

 exposed to wear, and therefore would grow to an indefinite, 

 and, consequently, most inconvenient length, if the shoe should 

 chance to be retained too long, and the excessive growth of 

 horn not removed. The sole and frog, on the contrary, never 

 cause inconvenience, as their growth is limited. 



What is required in shoeing, then, in principle, is merely 

 protection from undue wear, with the least possible inter- 

 ference with, or disturbance to, the functions of the foot and 

 limb. The excess in length of the wall must be removed at 

 frequent intervals between a fortnight and a month accord- 

 ing to the activity of the growth ; but the sole and frog, if 

 healthy, should not be disturbed. Not a grain of iron more 

 than is absolutely necessary should be allowed as a protection ; 

 and this question of weight of shoes is an important one, 

 especially with horses which are compelled to travel beyond a 

 walk. There are no muscles below the knee and hock, and 

 those which are chiefly concerned in the movements of the 

 limb arise high up, and act upon short levers. An ounce 

 weight at the shoulder or stifle, therefore, progressively and 



