39G 



hoof lias overgrown it until the heels rest uj^on the sole and bars, be- 

 comes a direct cause of corns. Indirectly the shoe becomes the cause 

 of corns when small stones, hard dry earth, or other objects collect 

 between the sole and shoe. Lastly, a rapid gait and excessive knee 

 action, especially on hard roads, predispose to this disease of the feet. 

 *S'//7??j5/o?».s'. — Ordinarily a corn induces sufficient pain to cause lame- 

 ness. It may be intense, as seen in sujipui'ative corn, or it may be 

 but a slight soreness, such as that which accompanies dry corn. It 

 is by no means unusual to see old horses having chronic corns appar- 

 ently so accustomed to the slight i)ain which they suffer as not to limp 

 at all; but these animals are generally very restless; they paw their 

 bedding behind them at night, and in many instances they refuse to 

 lie down for any lengthened rest. The lameness of this disease, how- 

 ever, can hardly be said to be characteristic, for the reason that it 

 varies so greatly in intensity; but the position of the leg while the 

 patient is at rest is generally the same in all cases. The foot is so 

 advanced that it is relieved of all weight and the fetlock is flexed 

 until all pressure by the contents of the hoof is removed from the 

 heels. In suppurative corn the lameness subsides or entirely dis- 

 appears as soon as the abscess has opened. AVhen the injured tissues 

 are much inflamed, as may happen in severe and recent cases, the 

 heel of the affected side, or even the whole foot, is hot and tender to 

 pressure. In dry corn, and in most chronic cases, all evidences of 

 local fever are often wanting. It is in these cases that the patient 

 goes w^ell when newly shod, for the smith cuts away the sole over the 

 seat of injury until all i)ressuro b}' the shoe is removed, and lowers 

 the heels so that concussion is reduced to a minimum. If a corn is 

 suspected the foot should be examined for increased sensibility of the 

 inside heel. Tapping the heel of the shoe with a hammer and grasp- 

 ing the wall and bar between the jaws of a pincers, with moderate 

 pressure, will cause more or less flinching if the disease is present. 

 For further evidence the shoe is removed and the heel cut away with 

 the drawing knife. As the horn is pared out not only the sole in the 

 angle is found discolored, but, in many instances, the insensible 

 laminae of the bar and Avail adjacent are also stained with the escaped 

 blood. In moist and suppurative corns this discoloration is less 

 marked than in dry corn and may be even entirely Avanting. In these 

 cases the horn is soft, often Avliite, and stringy or mealy, as seen in 

 pumiced sole resulting from founder. When the whole thickness of 

 the sole is discolored and the horn dry and brittle it is generally evi- 

 dence that the corn is an old one and that the exciting cause has 

 existed continuously. A moist corn differs from the dry corn in that 

 the injury is more severe, the parts affected are more or less inflamed, 

 and the horn of the sole in the angle is undermined b}^ a citron-colored 

 fluid, which often permeates the injured sole and laminae, causing the 

 horn to become somewhat spongy. 



