KNEB, FETLOCK, ANKLE, AND FOOT. 187 



placed upon the ground, whereby it receives much more concussion 

 than the heel of the hind-foot, in which the toe first strikes the 

 ground. 



Causes. It may be said that all feet are exposed to corns, and that 

 even the best feet may suffer from them when the conditions necessary 

 to the production of the peculiar injury are present. The heavier breed 

 of horses generally used for heavy work on rough roads and streets 

 seems to be most liable to this trouble. Mules rarely have corns. 



Among the causes which lead to corns may be named high heels, 

 which change the natural position of the bones of the foot; contracted 

 heels, which partly destroy the elasticity of the foot; long feet, which 

 by removing the frog and heels too far from the ground, deprive them 

 of necessary moisture, weak feet, or those in which the horn of the wall 

 is too thin to resist the tendency to spread. Wide feet with low heels 

 are always accompanied by a flat sole whose posterior wings either rest 

 upon the ground or the shoe. 



Improper shoeing either as a direct or a predisposing cause, produces 

 manj' corns. One of the most serious as well as the most common of 

 the errors in shoeing is to be found in the preparation of the foot for the 

 shoe. Instead of seeking to maintain the strength of the arch the first 

 thing done is to weaken it by paring away the sole; the mutilation does 

 not end here, for the frog is also largely cut away. This permits an ex- 

 cessive downward movement of the contents of the horny box, and at 

 the same time removes the means by which concussion of the foot is 

 destroyed. There is also faulty construction of the shoe and the way it 

 is adjusted to the foot. An excess of concavity in the shoe, by extend- 

 ing it too far back on the heels, high calks, thin heels which permit the 

 shoe to spring, short heels with a calk set under the foot, and a shoe 

 too light for the animal wearing it or for the work required of him, are 

 all to be avoided as causes of corns. A shoe so set as to press upon the 

 sole, or one that has been on so long that the hoof has overgrown it 

 until the heel rests upon the sole and bars, becomes a direct cause of 

 corns. Small stones, hard dry earth, or other objects which collect be- 

 tween the sole and shoe is often the cause of corns. Lastly, a rapid gait 

 and excessive knee action, especially on hard roads, predispose to this 

 disease of the feet. 



Sytnptoms. Usually a corn causes enough pain to cause lameness. 

 It may be intense as seen in suppurative corn, or it may be a slight sore- 

 ness, such as that which accompanies dry com. It is by no means un- 



