382 



horny matter, wliich are not firmly adherent must be rubbed off with 

 the finger or a tent of oakum. As the secretion diminishes dry jiovrders 

 may prove of most advantage, such as calomel, sulphates of iron, 

 copper, etc. The sulphates should not be used pure, but are to be mixed 

 with powdered animal charcoal in the proportion of one of the former to 

 eight or ten of the latter. When the soft tissues are all horned over the 

 dressings should be continued for a time, weak solutions being used to 

 prevent a recurrence of the disease. If the patient is run down in con- 

 dition, bitter tonics, such as gentian, may be given in 2-dram doses, 

 twice a day, and a liberal diet of grain allowed. 



CORNS 



A corn is an injury to the living horn of the foot, involving at the 

 same time the soft tissues beneath, whereby the capillary blood vessels 

 are ruptured and a small amount of blood escapes, which, by permeat- 

 ing the horn in the immediate neighborhood, stains it a dark color. If 

 the injury is continuously repeated the horn becomes altered in char- 

 acter, the soft tissues may suppurate, causing the disease to spread, or 

 a horny tumor may develop. Corns always appear in that part of the 

 sole included in the angle between the bar and the outside wall of the 

 hoof. In many cases the laminre of the bar, of the wall, or of both, are 

 involved at the same time. 



Three kinds of corns are commonly recognized — the dry, the moist, 

 and the suppurative, a division based solely on the character of the 

 conditions which follow the primary injury. 



The forefeet are almost exclusively the subjects of the disease, for two 

 reasons: First, because they support a greater part of the body; sec- 

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

 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 elasticity of the foot, 

 increase the pressure upon the soft tissues of the heel, and render lacer- 

 ations 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 properties 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 tendency to spread, and as a result the soft tis- 

 sues are easily lacerated. Wide feet with low heels are always accom- 



