There are few ailments that lame more or cause more acute pain to the horse than do corns, if not properly treated, and few that are more easily alleviated if scientifically set about. Corns, I quite believe, are a disease incident to some horses, as I am quite convinced they are to some persons. Skilful chiropodists will so far alleviate their effects, that a man may walk and feel no inconvenience from them: this in no way proves that he cures them-his skill may prevent any inconvenience being felt for weeks, or months, but the disease continues, and in time, less or more, its effects will be found to continue. It is a received axiom that pressure produces corns. I do not conceive it quite amounts to this: the germ of the disease is there, and pressure produces lameness; but I am very much inclined to doubt whether pressure would produce a bond fide corn in a perfectly healthy foot; it would certainly produce a bruise; but if a corn was not inherent in the foot, I feel clear that so soon as such bruise was found and cured, it would be, like a bruise of any sort, cured radically. If the same improper pressure was applied, of course the foot would be again bruised, again to be cured; and afterwards shoe the horse fairly and well, we should find no more of the temporary ailment.
Let us now consider of what leading characters the foot of the horse consists. There will be found to be the wall, or crust, the sole (covering) the sensible part of the foot, the frog, and the bars. Now these bars join the crust of the foot at the heel, and form an acute angle there, from whence (hey run to the narrow point or termination of the frog. It must be quite clear to any one that any sensible part of the foot confined, I may say jammed in, by an acute angle formed by the two different parts, that foot must more or less undergo the pressure spoken of; and it is in this angle between the bars and wall of the foot that corns are inherent, or the bruises I have spoken of are found to exist. It may be asked, and very reasonably, as the horse's foot is formed the same on the inside as the out, and the shoe formed the same, or nearly so, at both heels, how happens it that a corn on the outside is a circumstance of very rare occurrence? The only reason I can surmise is, that, from some natural cause, he treads heavier on the inside than the out; and, supposing my idea to be correct, we have not found out any mode to prevent this. Having stated the nature of corns, to the best of my experience, observation, and anatomical knowledge of the foot, I will state other causes that produce pressure besides the being confined in the corner spoken of between the bars and the crust: this is pressure from the upper surface, namely, the sole. This, as may be at once apparent, produces the same effect or result as does the accumulation of hardened substance that from time to time thickens on our corn, if we are unfortunate enough to have one. Most persons are more or less quite acquainted with the pain it creates. It is the same with the horse. It would be well for him if we could at once, and as effectually, relieve him as we can ourselves; but, unfortunately, common blacksmiths do not do this, or even set about it the right way to effectually produce the wished effect. Many persons have remarked that a horse with corns will frequently, I will say generally, go firm and sound for some days, more or less, after being shod. The fact is, the cause of lameness has been for a brief time removed, that is, the corn has been relieved of pressure. Smiths are apt enough to slice away at the frog. They have learned from practice and observation that the upper coat for a certain thickness is perfectly insensible, and have ascertained by practice also how far they may, in the generality of cases, go before they approach the sensible part. I never found a smith who thus acted, who could give a more sensible reason for his cuttings than that "it kept the frog in shape and looked neat"when the new-shod foot was looked at.
With deference to these gentry, I beg to say it never fell to my lot to see a frog grow out of proper shape, except in a state of disease. I have seen in a common smith's pent-house half-a-dozen curs waiting for the cuttings from horses' frogs, of which they are inordinately fond. They might wait long enough at Mr. Field's, of Oxford Street, before they got a chance of a "bonne bouche." The closely paring a horse's healthy frog is tantamount to taking a man's comfortable walking shoes off, and turning him going on a newly macadamised road in a pair of dancing pumps.
They have heard that the bars are intended to "spread the hocks." They were intended for no such thing, but were placed there to support the crust and retain the foot in its natural and healthy shape; what shape it may contract from acute disease is another matter. They are not content to take away as much of the wall, the sole, and the bars, as to place them in the same relative position as regards each other as they were before, but will pare down the sole, leaving the bars standing up a perfect ridge each side the horse's frog-I suppose from thinking they are better judges of proportion than is or was Nature, who formed the foot. If we send a horse to an inferior smith, and the servant tells him the horse has corns, he usually begins by lowering the wall or crust, whether it wants it or not; he then holds it necessary to take away a certain part of the insensible sole, whether there is any overgrowth or not. He then comes to the frog, which he works away at till its appearance pleases him; then comes the rasp, to bring, if possible, the foot to a certain shape. If naturally a spread or wide one, the rasp travels along the out and inner side-the workman, with a knowing look, regarding it till he has probably weakened the crust so far as to render it a matter of serious difficulty and risk to find hold for the nails. This done, he sets to work to find the corn. For this purpose a small drawing knife, called "a searcher," is called into requisition; with this, (I can find no better term) he digs away where practice has taught him the corn is to be expected-namely, the inside heel between the crust and the bar. I should mention that, prior to such anatomical search, in most cases he sets the foot on the ground, and, coming in front, probably says to the servant, with a self-satisfied air, "There! his foot looks a very different thing to what it did when you brought him." But to return to the searching. After considerable digging in the corner, and the whole superstructure of sole being removed, the corn is come at, and, as it sometimes happens, the sensible part of the foot is come at also.