395 



The forefeet are almost exclusively the subjects oL' the disease, for 

 two reasons: First, because they supi)ort a greater part of the bodj'-; 

 secondly, because the heel of the fore foot during progression is first 

 placed ui)on the ground, Avhereby it receives mucli more concussion 

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



Causes. — It maybe said that all feet are exposed to corns, and that 

 even the best feet may suffer from them when the conditions neces- 

 sary to tlie production of the peculiar injury are present. The heavier 

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

 streets seem to be most liable to this trouble. Mules rarely have 

 corns. 



Among the causes and conditions which predispose to corns may be 

 named high heels, -which change the natural relative position of the 

 bones of the foot and thereby increase the concussion to which these 

 parts are subject; contracted heels, which in part destroy" the elas- 

 ticity of the foot, increase the pressure upon the soft tissues of the 

 heel, and render lacerations more easy; long feet, which, by removing 

 the frog and heels too far from the ground, deprive them of necessary 

 moisture, which in turn reduces the elastic iDroperties of the horn and 

 diminishes the transverse diameter of the heels; weak feet, or those 

 in which the horn of the wall is too thin to resist the tendenc}' to 

 spread, and as a result the soft tissues are easily lacerated. Wide 

 feet with low heels are always accompanied by a flat sole whose pos- 

 terior wings either rest upon the ground or the shoe, and as a conse- 

 quence are easily bruised ; at the same time the arch of the sole is so 

 broad and flat that it can not support the weight of the bodj^, and in 

 the displacement which happens when the foot is rested upon the 

 ground the soft tissues are liable to become bruised or torn. 



It is universallj^ conceded that shoeing of the foot, either as a direct 

 or predisposing cause, is most jDrolific in iiroducing 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 seek- 

 ing to maintain the integrity of the arch the first thing done is to 

 Aveaken it bj- freel}' paring away the sole; nor does the mutilation 

 end here, for the frog, which is nature's mainsupi^ort to the branches 

 of the sole and the heels, is also largely cut away. This not only per- 

 mits of an excessive downward movement of tlie contents of the horny 

 box, but it at the same time removes the one great means by which 

 concussion of the foot is destroyed. As adjuncts to the foregoing- 

 errors must be added the faults in the construction of the shoe and 

 in the way it is adjusted to the foot. An excess of concavity in the 

 shoe, by extending it too far back on the heels, high calks, thin heels 

 which permit the shoe to spring, short heels Avith 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 



