In the operation of shoeing, injury is sometimes inflicted by the farrier, either through ignorance, carelessness, or pure accident. Corns have been already alluded to as often due to bad shoeing; but in driving the nails the sensitive part is liable to be damaged by a nail being either driven into it, or so near it as to cause pain and lameness. When the farrier discovers that he has made this mistake, he usually withdraws the nail at the time, and, if he leaves it out altogether, no harm may ensue, provided dirt does not get into the part; if, however, the nail be left in, or grit find admission, inflammation will be set up, which may run on to suppuration, causing much suffering and lameness. The foot will be very hot, and the animal, if standing quiet, continually resting it, or moving it about uneasily, afraid to put his weight upon it. If tapped with a hammer over the spot, or if the sole and wall at the part be pressed upon by pincers, great suffering will be manifested; this is usually the guide to the seat of injury.
Remove the shoe, pare away the sole immediately over the injury, until it is quite thin; make an opening between the sole and the wall with a small drawing-knife across the track of the nail, so as to relieve pressure, and give exit to any matter which may have formed; then put the foot in a bucket of hot water for an hour or so, afterwards applying a large poultice. When the lameness has gone have the shoe put on again, leaving out the nail at the part which had been injured, and filling up the cavity with tar and tow.
Sometimes in driving back the clip of the shoe against the hoof, this is done improperly, which results in pressing tightly against the wall, and bruising the sensitive parts within. In putting the clip against the hoof, the hammer should be applied at the base first, and then come lightly up to the point. It is the opposite procedure which usually causes damage.
The treatment consists in taking off the shoe, and fomenting the foot in hot water for some time; if need be, a poultice may be applied.
It not unfrequently happens that, with a tender-footed horse, the farrier nails on the shoe too tightly, causing a short and crippled gait, which may not disappear for some days; inflammation may even ensue. The remedy for this is to take off the shoe and put it on more easily, or with smaller nails.