If the wound is clean and recent, enlarging the opening in the horn by cutting and boring can have no reasonable object; the wound by such an act will not be made smaller, but larger.
Frequently, however, the wound is not observed or suspected until the pain has become very intense (indirect nailing, nail-pressure); in such cases the offending nail when withdrawn is apt to be covered with pus or a dark, thin, ill-smelling liquid. In such a case the liquid, whatever its nature may be, must be given free escape. In order to accomplish this it is entirely sufficient to cut away a section of the wall from the nail-hole outward, not greater than the width of the little finger, and then to assist in the discharge of the pus by placing the foot in a warm bath; it is entirely wrong, in fact, reprehensible, to remove all horn of the wall and sole which has been loosened from the soft parts by the suppurative process. After the escape of the inflammatory fluids, the wall and sole will form the best-fitting and most suitable protective dressing for the diseased region until it has secreted new horn. If, after removal of the nail and pus, the pain does not diminish, warm disinfecting baths of one to two parts of creolin, or the same amount of lysol, to one hundred parts of water at a temperature of about 90° F. will be of especial benefit; they will not only soften the horn, but by their moisture and warmth will directly diminish the pain and have a healing influence upon the suppurating surfaces. The warm baths must actually be warm and be kept warm. Antiseptic solutions at room temperature are much less efficient.
If the pain has not been very pronounced, or if it has been greatly alleviated by two or three warm baths, then, as a rule, it is sufficient to put a few drops of creolin upon the inflamed surface, and to close the opening with oakum (carbolized oakum or carbolized cotton is better).
The horse which has been nailed will be again perfectly serviceable after a few days if shod with a shoe which does not press upon the inflamed region. The shoe does not press when it rests only upon the bearing-edge of the wall, when the white line and the edge of the sole are entirely free of the shoe, and no nails are driven in the immediate vicinity of the wound.
Even though, as we have seen, nailing in the great majority of cases is not particularly serious to the horse and owner, yet we should never forget that tetanus (lockjaw), a disease which is nearly always fatal to horses, may follow. Nailing, however insignificant it may seem, may under conditions lead to the death of the horse.
2. Street-Nail.
The condition caused by accidental injury of the sensitive structures covered by the horny sole, such as the velvety tissue of the sole and frog, plantar cushion, perforans tendon, navicular bone, os pedis, or the pedal articulation, by sharp objects, especially nails, is called “penetrating street-nail,” or simply “street-nail.” The resistance of the ground to the weight of the body drives these penetrating objects through the sole or frog into the foot.
Hind hoofs are more often affected than fore-hoofs. A favorite point of entrance is the lateral lacuna of the frog. Street-nail is favored by excessive thinning of the sole and frog.
Symptoms.—The symptoms are, as a rule, sudden pain followed by lameness. The first assistance is usually sought in the shoeing shop. If the cause of lameness be found to be a penetrating nail, piece of glass, or other pointed foreign body, it must be carefully drawn out, in doing which we should remove the entire object, not allowing pieces to break off and remain in the wound. Since it is always important to know in what direction and how deep the foreign body has penetrated, in order to be able to estimate the gravity of the wound, it is advisable in all cases to preserve the penetrating body, that it may be shown to the veterinarian, in case his services are required.
Fig. 188.