Abundant but not excessive exercise is more necessary than anything else to the preservation of the health of the hoof. It aids the circulation of blood within the foot, and, therefore, the growth of the horn. Horses which perform hard, regular work have, as a rule, better hoofs than those which stand the greater part of the time in the stable. Poulticing hoofs with clay, bran, linseed-meal, or white-rock, or standing them in water is unnecessary if they have had proper care, but will sometimes be of benefit when the hoofs have been neglected, and especially so for front hoofs. The latter are more exposed to drying influences, and the shoes prevent the moistening process by keeping the hoofs partially or completely removed from contact with the earth. Oiling alone is not sufficient to soften horn, but must always be preceded by permeation of the horn with water. Oiling without first cleansing the hoof is useless, because this soon produces a greasy crust underneath which the horn is crisp and brittle.
The surest sign of cleanliness of a hoof is the appearance of the natural color of the horn, the latter appearing translucent even after the hoof-ointment has been applied; therefore, blackened hoof-ointments should not be used. When hoofs are exposed to too much moisture (muddy roads, melting snow, etc.) an addition of wax or common yellow rosin to the hoof-ointment is recommended to prevent too great softening of the horn. No hoof-ointment has any direct influence upon the growth of the horn.
Inasmuch as it is a fact that the very best shoeing injures the hoof, it is advisable to allow horses to go barefoot whenever it is possible. This applies especially to horses that from any cause are thrown out of service, presupposing, of course, that the nature of the hoofs will allow them to go barefoot.
PART III.
CHAPTER VII.
GENERAL REMARKS CONCERNING THE SHOEING
OF DEFECTIVE HOOFS AND LAME HORSES.
The boundary between health and disease of the hoof is difficult to determine, especially when we have to deal with minor defects of structure or shape of the hoof. Ordinarily, we first consider a hoof diseased when it causes lameness. However, we know that diseases of the hoof may exist without lameness. Therefore, a hoof should be regarded as diseased or defective when the nature of the horn, the form of the hoof, or the parts enclosed by it, deviate from what we consider as normal or healthy ([see page 81]), whether the service of the animal is influenced by it or not.
Front hoofs become diseased or defective more readily than hind hoofs, because they bear greater weight, have more slanting walls, and are more exposed to drying influences. All normally wry hoofs and acute-angled hoofs become more readily diseased than regular and upright (stumpy) hoofs.
The indications of the various diseases of the hoof are discussed in the following chapters. We shall in this chapter undertake only a brief general discussion of inflammation of the pododerm. This inflammation, known as pododermatitis, always manifests itself by lameness and, under closer examination of the foot, by increased warmth, pain, and stronger pulsation of the digital and plantar arteries. The pain produces either a timid, shortened (sore) gait, or well-marked lameness, especially upon hard ground. Increased sensitiveness of the pododerm is detected by compression of the hoof with the pincers (hoof-testers), or with greater certainty by lightly tapping the hoof. The increased warmth of a part or of the entire hoof is detected by feeling with the hand. Intense pain and greatly increased warmth, with a moderate, diffuse swelling of the soft parts between the hoof and fetlock-joint, indicate suppuration within the hoof.
The examination of horses lame in the feet must always be cautious and searching, and should begin with the moving and judging of the horse as already described on page 90. The faults detected in the hoof or in the shoeing, the pain and increased warmth of the hoof, will not leave us in doubt as to whether the animal is lame in the hoof or not. However, should there be a doubt, we must carefully examine all the joints and tendons of the foot and, if necessary, of the limb above, and observe the animal’s manner of travelling at a walk and at a trot, on soft and on hard ground, in a straight line and in a circle.
The removal of the shoe should be performed with greatest caution. Under certain conditions the second shoe should not be removed until the first has been replaced. The same caution must be observed in paring the hoof, which is to be regarded as a part of the examination of the hoof. The paring of a hoof for this purpose often differs somewhat from the preparation of a sound hoof for the shoe, and while it is necessary because it frequently furnishes the first trustworthy indication of the trouble, it must be done with circumspection and intelligence.