724 SHOEINa. 



Consequently the secreting membrane above it, is particularly- 

 liable to injury. 



If we examine the worn shoe of a normal fore foot, we shall 

 find that it has sustained the greatest amount of wear a little to 

 the outside of the toe and not in the exact direction of the long 

 axis of the foot. In fact, the outside half of a normal fore foot 

 sustains more wear than the inside half, an inference which we 

 might draw from the fact that the horn of the former is thicker 

 than that of the latter. 



In order to meet the wear and tear to which the foot is 

 subjected by contact with the ground, when the animal roams 

 about under natural conditions, the horn of the wall is endowed 

 with the property of growing to a practically indefinite length; 

 though the horn of the sole and frog will not increase beyond a 

 useful limit. The thickness of the sole is regulated naturally 



Fig. 184. — Lowering hoof all round. Fig. 185. — Lowering toe. 



by its outer layers of horn exfoliating (flaking off), when the 

 sole has reached its proper thickness. The frog cannot, under 

 ordinary conditions, grow too longj firstly, because its outer 

 layers, also, flake off ; and, secondly, because it will stop increasing, 

 as soon as it is relieved of pressure by reason of the more rapid 

 growth of the wall. As we require, when shoeing, to utilise the 

 whole of the weight-bearing surface at our disposal, as well as to 

 preserve the horn-secreting meonbrane from injury; we may con- 

 clude that the sound parts of the frog and of the arched portion of 

 the sole should be left untouched by the knife or other instrument, 

 and that the wall and bars should be kept sufficiently " short," to 

 allow the frog and outer portion of the sole, also, to support weight. 



Form of the Healthy Foot. 



1st. The frog is large (Fig. 49, p. 167) and comes well down 

 on the ground, so as to act as a buffer in diminishing the effects 

 of concussion, and also, by its form and nature, to prevent the 

 animal from slipping. 



