648 OPERATIONS ON THE FOOT. 



cause of this lesion of the hoof if uot practiced with the intelli- 

 gence it requires. We have said, in speaking of corns, that they 

 were proofs of bad shoeing. The same might be said of the con- 

 traction. Moreover, corns generally indicate great errors in shoe- 

 ing, while hoof-bound demonstrates the ignorance of the physiology 

 of the hoof, which in action must enjoy the necessary elasticity to 

 reheve the contact with the weight of the body upon the ground. 

 No doubt the theory of Bracy Clark exaggerates the degree of 

 elasticity in admitting a great power of dilatation of the hoof, but 

 it is an opposite excess to deny it entirely. The dilatation of the 

 hoof, though limited, is evident at the heels; especially on feet 

 which have never been shod (Merche). There is especially in the 

 inside of the foot, in the soft and supple parts, a certain compres- 

 sibHity of the hoof, which is often overlooked, and which is inter- 

 fered with by a too narrow or unmethodical shoeing. 



The external dilatation of the hoof is comparatively limited, 

 but on the inside of the hoof there is, in the posterior part of the 

 foot (especially in the fore feet) a movement downward and out- 

 ward of the OS pedis, for whether the normal elasticity of the hoof 

 is necessary, either by the physical and physiological constitution 

 or the arrangement of the constituent parts of the hoof. Quite 

 often, then, shoeing, especially if too tight, resists the internal 

 jjressure. Even admitting that the dilatation of the heel is nor- 

 mal, shoeing which would prevent it, would always produce, at 

 the time of rest, a pressure upon the hoof which would hmit the 

 compressibihty of the deep, soft tissues. The frog, especially, 

 formed of a softer horn, and placed under the plantar cushion, 

 must receive this gradual pressure, which diminishes by degrees 

 as the hoof becomes harder, and is reduced considerably as it 

 reaches the external horny layers. 



The errors committed in shoeing, and which predispose to 

 hoof-bound, vary. The first is in the manner in which the foot is 

 pared ; too often the heels are lowered to excess, while the toe is 

 allowed to remain too long ; too often, again, the bars are hoUowed 

 too deeply, thinned too much, as well as the frog. The waU then 

 tends to retreat, as it is no longer protected behind. In reducing 

 the height of the heels, in opening them, the tendency to contrac- 

 tion is increased ; the thinned hoof dries up, the lowered heels 

 lose their strength, and- the bars are vmable to perform their 

 functions. 



