CORNS. 317 



In searching the foot in order to ascertain the existence of prick, there is often 

 something very censurable in the carelessness with which the horn is cut away 

 between the bottom of the crust and the sole, so as to leave little or no hold for the 

 nails, although some months must elapse before the horn will grow down sufficiently 

 far for the shoe to be securely fastened. 



When a free opening has been made below, and matter has not broken out at the 

 coronet, it will rarely be necessary to remove any portion of the horn at the quarters, 

 although we may be able to ascertain by the use of the probe that the separation of 

 the crust extends for a considerable space above the sole. 



CORNS. 



In the angle between the bars (c, p. 297) and the quarters, the horn of the sole has 

 sometimes a red appearance, and is more spongy and softer than at any other part. 

 The horse flinches when this portion of the horn is pressed upon, and occasional or 

 permanent lameness is produced. This disease of the foot is termed corns : bearino- 

 this resemblance to the corn of the human being, that it is produced by pressure, and 

 is a cause of lameness. When corns are neglected, so much inflammation is pro- 

 duced in that part of the sensible sole, that suppuration follows, and to that, quittor 

 succeeds, and the matter either undermines the horny sole, or is discharged at the 

 coronet. 



The pressure hereby produced manifests itself in various ways. When the foot 

 becomes contracted, the part of the sole inclosed between the external crust that is 

 wiring in, and the bars that are opposing that contraction (see cut, p. 297), is placed 

 in a kind of vice, and becomes inflamed ; hence it is rare to see a contracted foot with- 

 out corns. When the shoe is suffered to remain on too long, it becomes embedded in 

 the heel of the foot : the external crust grows down on the outside of it, and the bear- 

 ing is thrown on this angular portion of the sole. No part of the sole can bear con- 

 tinued pressure, and inflammation and corns are the result. From the length of wear 

 the shoe sometimes becomes loosened at the heels, and gravel insinuates itself 

 between the shoe and the crust, and accumulates in this angle, and sometimes seriously 

 wounds it. 



The bars are too frequently cut away, and then the heel of the shoe must be bevelled 

 inward, in order to answer to this absurd and injurious shaping of the foot. By this 

 slanting direction of the heel of the shoe inward, an unnatural disposition to contrac- 

 tion is given, and the sole must suffer in two ways, — in being pressed upon by the 

 shoe, and squeezed between the outer crust and the external portion of the bar. The 

 shoe is often made unnecessarily narrow at the heels, by which this angle, seemino-ly 

 less disposed to bear pressure than any other part of the foot, is exposed to accidental 

 bruises. If, in the paring out of the foot, the smith should leave the bars prominent, 

 he too irequently neglects to pare away the horn in the angle between the bars and 

 the external crust; or if he cuts away the bars, he scarcely touches the horn at this 

 point ; and thus, before the horse has been shod a fortnight, the shoe rests on this 

 angle, and produces corns. The use of a shoe for the fore feet, thickened at the heels 

 is, and especially in weak feet, a source of corns, from the undue bearing there is on 

 the heels, and the concussion to which they are subject. 



The unshod colt rarely has corns. The heels have their natural power of expan- 

 sion, and the sensible sole at this part can scarcely be imprisoned, while the projec- 

 tion of the heel of the crust and the bar is a sufficient defence from external injury. 

 Corns seem to be the almost inevitable consequence of shoeing, which, by limiting-, 

 or in a manner destroying, the expansibility of the foot, must, when the sole attempts 

 to descend, or the cofl'm-bone has a backward and downward direction (see cut, p. 

 272), imprison and injure this portion of the sole. This evil consequence is increased 

 when the shoe is badly formed, or kept on too long, cf when the paring is omitted or 

 injudiciously extended to the bars. By this unnatural pressure of the sole, blood is 

 thrown out, and enters into the pores of the soft and diseased horn which is then 

 secreted ; therefore the existence and the extent of the corn is judged of by the colour 

 and softness of the horn at this place. 



Corns are most frequent and serious in horses with thin horn and flat soles, and low 

 weak heels. They do not often occur in the outside heel. It is of a stronger con- 

 struction than the inside one. The method adopted by shoeing-smiths to ascertain 

 the existence of corn by the pain evinced when they pinch the bar and crust with 

 27 •• 



