G. Choosing the Shoe.
The choice of the shoe for a given horse is not at all difficult after we have carefully considered his weight, the nature of his work, his standing position, gait, the form of his hoofs, and quality of the horn, bearing in mind the general and peculiar properties of shoes. As a rule, we choose a shoe that is longer than the hoof, because the latter grows and carries the shoe forward with it, and because the quarters gradually become lowered by rubbing and wearing away upon the branches of the shoe. The length of the shoe is of especial importance. For horses employed for slow, heavy draft purposes the shoe supplied with heel-and toe-calks should extend backward far enough to support the bulbs of the heels. On the contrary, horses used at a trot or gallop, as coach-and saddle-horses, require shorter shoes ([see Fig. 124]).
The weight of the shoe should be so adjusted to the demands of the horse’s work, the condition of the legs (whether used up with work or not), and the nature of the ground that the shoeing will last at least a month. Hard roads and a heavy, clumsy gait require strong, durable shoes, which, under some conditions, are to be rendered still more durable by welding in steel. For moderate service upon soft roads we should use light shoes. Running horses require unusually thin and narrow shoes of steel ([see Figs. 125-128]).
H. Shaping and Fitting Shoes.
General Considerations.
This is one of the most important parts of horseshoeing. Its object is to so fashion or shape the shoe which has been chosen for a particular hoof that its circumference will exactly correspond to the lower circumference of the previously prepared hoof, and its bearing-surface will fit air-tight to the bearing-surface of the hoof. At this time all defects in the surfaces of hoof and shoe and in the nail-holes must be remedied, the clips drawn up, and the shoe made to fit perfectly. The bearing-surface of the shoe, especially at the ends of the branches, must be kept horizontal[4] and smooth, and its width regulated by the width of the bearing-surface of the hoof ([see page 99]). Perfectly uniform heating is absolutely indispensable in shaping the shoe, because an irregularly heated shoe twists or becomes distorted at the warm places. Every shoe should be straight, and when held before the eye one branch should exactly cover the other. A flat shoe laid upon a level surface should touch at all parts of its ground-surface; the only exception to this is the shoe with a rolled toe (rolling motion), in which the toe is turned upward. A shoe is termed “trough-shaped” when only the inner edge of the web rests upon the flat surface. It is faulty, disturbs the stability of the foot, and shifts the weight of the body too much upon the quarters.
Fig. 121.
Shod fore-hoof viewed in profile
to show the “roll” at the toe.
To front shoes we give a rolled toe ([Fig. 121], rolling motion), by which we mean a more or less pronounced upward turn of the toe of the shoe. Ordinarily, the toe begins to turn up at the middle of the web, and should be elevated about one-half the thickness of the iron. The rolled toe corresponds to the natural wear of front hoofs, facilitates the “breaking over” of the feet, and insures a uniform wear of the shoe ([see Fig. 86]). The shoe is made moderately hot and placed on the foot with the toe-clip against the wall exactly in front of the point of the frog. The scorched horn should be repeatedly removed with the rasp until a perfect-fitting bed has been made upon the bearing-surface of the hoof. From the bearing-surface of the shoe to the inner border of the web the iron must be free from the sole around its entire circumference. The horn sole should not be burnt, because the velvety tissue of the sole lies immediately above it. In the region of the nail-holes the outer borders of shoe and wall should correspond. The nail-holes must under all conditions cover the white line. From the last nail-hale back to the ends of the branches, for hoofs of the regular standing position of the limbs, the shoe should gradually widen until it projects at each quarter from a sixteenth to an eighth of an inch beyond the edge of the wall. The posterior half of the shoe should, therefore, be somewhat wider than the hoof. The effect of this will be to prolong the usefulness of the shoes. With respect to the width of the branches, an exception arises in the case of hind shoes, in which the inner branch, with few exceptions, should closely follow the border of the wall; this will prevent interfering and tearing off the shoe by the opposite foot.
Fig. 122.