This preparation is usually termed paring, trimming, or dressing. It is a most important step in the process of shoeing, and its object is to shorten the hoof, which has grown too long under the projection of the shoe, and prepare it to receive the new shoe. The instruments needed for this work are the rasp and the hoof-knife ([Fig. 95]); upon large and hard hoofs a pair of sharp nippers ([Fig. 96]), or a sharp hewing knife, with broad handle and perfectly flat, smooth sides, may be used, since these instruments will considerably facilitate and hasten the work.
Fig. 95.
German hoof set with detachable hook blades. (W. M. Kunde, Dresden): a, a, hoof blades; b, pus searcher; c, scalpel.
After the shoer has carefully examined the hoofs in the manner described upon pages 90, 91, and 92, and has fixed in mind the relation of the height of the hoofs to the size and weight of the body, he cleanses the hoof and removes all stubs of old nails. At the same time he should be asking himself if, where, and how much horn is to be removed. In all cases all loosely attached fragments of horn are to be removed, for example, chips of horn produced by repeated bending and stretching of the lower border of the wall. The sole is then freed from all flakes of dead horn. The shoer then runs the rasp around the outer border of the wall and breaks it off to the depth to which he thinks it should be shortened, and then cuts the wall down to its union with the sole, so that at least one-eighth of an inch of the edge of the sole lies in the same level as the bearing-surface of the wall. Finally, the wall, white line, and outer margin of the sole, forming the “bearing-surface,” must be rasped until they are perfectly horizontal, except that at the toe of fore-hoofs this bearing-surface may be rasped slightly upward (rolled toe).
In dressing the hoof the branches of the frog should always be left prominent enough to project beyond the bearing-surface of the quarters about the thickness of an ordinary flat shoe. If it be weakened by paring, it is deprived of its activity, shrinks, and the hoof becomes narrow to a corresponding degree. The frog should, therefore, be trimmed only when it is really too prominent. However, loose and diseased particles of horn may be trimmed away when it is affected with thrush.
Fig. 96.
Nippers.
The bars should be spared and never shortened except when too long. Their union with the wall at the quarters must in no case be weakened, and never cut through (opening up the heels). They should be left as high as the wall at the quarters, or only a little less, while the branches of the sole should lie about one-eighth of an inch lower.