Fig. 184.
Left front long pastern of a colt showing compression shortening of outer half: a, transverse axis of upper articulation; b, transverse axis of coronary joint, not parallel to upper axis.
Too early shoeing of young horses is very injurious; it hinders the development of the hoofs, and, furthermore, young horses when shod are frequently seriously overworked and prematurely ruined. Moderate work in the fields does not injure young horses, but for such service they do not require shoes.
The unshod hoofs of older horses should be periodically rounded with a rasp and the length of the walls regulated when, by reason of a lack of exercise, proper wear has not taken place.
B. Care of Shod Hoofs.
Shod hoofs are exposed to many more injuries than are unshod hoofs, because shoeing itself, although absolutely necessary to render horses continuously serviceable upon hard streets, is injurious to the hoof, since it to a greater or less extent prevents the physiological movements of the different parts of the foot, interferes with the circulation of the blood in the foot, slows the growth of the horn, and brings about a gradual shrinking of the entire hoof.
In addition, there are the injurious consequences of stabulation. These are prevention of free movement, uncleanliness due to bad floors and filthy bedding,—as, for example, peat moss and soiled straw,—and dryness.
Continuous standing always contributes to contraction of the hoofs, and this evil is greatly favored by dryness, which more particularly affects the front hoofs. The hind hoofs receive sufficient moisture from the animal’s manure. Poor floors, particularly those that are uneven, tire the limbs. Accumulation of manure and the careless use of stationary sole-pads induce thrush of the frog.
The object of hoof nurture is to lessen or entirely remove all these injurious consequences of shoeing and stabulation. It comprises, therefore, not only the proper shortening of the hoofs every five to six weeks, but careful attention to cleanliness and moisture. Both are insured by dry straw and daily picking out and washing the hoofs. Such measures will prevent thrush in the hind feet. If front hoofs are washed once a day, sufficient moisture will penetrate the horn to give it that degree of suppleness (elasticity) which is possessed by an unshod hoof, and which contributes to a proper expansion of the hoof when the body-weight is placed upon it. In order to prevent a hoof from again drying out, the entire hoof should receive a thorough application of an oil or ointment (hoof-salve). The object of greasing the horn is to prevent evaporation of the moisture that has penetrated the horn. Specially compounded hoof-salves are not necessary. Melted horse-grease, pork-fat, or any other fat that is not rancid is sufficient. Cosmoline is an excellent hoof-salve.