In many European countries a shoe is used for toe-cracks which has two clips drawn on the inside border of the shoe at the heels. These clips catch the bars of the hoof and prevent the heels of the foot closing in. The idea is that when the wall at the heels contracts, there is a tendency for the wall at the toe, if separated by a crack, to open. [Fig. 85] shows the position of the clips which must be carefully fitted so as to rest on the inside of the bars. Mr. Willis, V.S., has tried these shoes and speaks well of their utility.
Fig. 85.—Shoe with Heel Clips for Sandcrack.
When the crack is in the quarters of the foot, it is not the tendency to expansion of the hoof that has to be guarded against. It is the downward motion of the heels that forces open a crack in this position. The farrier provides against this by taking care to have a firm bearing of the shoe on the hoof behind the crack as shown in A [figure 82].
Contracted Feet. Some diseases of the foot lead to contraction of the hoof, which is most noticeable round the coronet and at the heels. Any long continued lameness which prevents the horse placing the usual weight on the foot may be accompanied by contraction. Constant cutting away of the bars and paring the frog so that it takes no contact with the ground also leads to shrinking in of the heels. By lowering the heels and letting the frog alone many feet will in time widen out to their proper size, but no system of shoeing is so good for contracted feet as the use of tips, which leave the whole back part of the hoof to take direct bearing on the ground.
Many shoes have been invented for forcing open the heels of contracted feet. Some have had a hinge at the toe and a movable screw at the heel. Some have had the bearing-surface at the heels made with a slope outwards, (See [Fig. 53], [page 74]) so that the weight of the horse should constantly tend to force the heels apart. There is no necessity for any of these contrivances. A properly fitted tip (See [page 78]) will permit the hoof gradually to expand to its healthy size and form.
Seedy-toe. This is a condition of the wall usually found at the toe but not uncommon at the quarters. It is not common in hind feet but occurs sometimes. When the shoe is removed a separation is noticed between the sole and the wall, and this separation may extend up the wall nearly to the coronet. As a rule the space so formed is a narrow one, but it may be wide enough to admit three fingers of a man's hand. Probably all seedy toes result from some injury or disease of the coronary band from which the wall grows, and the first appearance is not a cavity but a changed and softened horn, which may be dry and crumbly, or moist and cheesy. The diseased horn may be scraped out and the cavity filled with tar and tow. The wall bounding the cavity should be relieved of all pressure on the shoe, and if a radical cure be desired all the unattached wall should be cut away. This, however, should be done under veterinary guidance.