Puncture wounds to the equine foot are frequently encountered by veterinarians and farriers. Puncture wounds may be classified as indirect or direct. With an indirect puncture wound, foreign material gains entrance to the foot through the sole wall junction (white line) or a crack in the hoof wall and migrates through the tissue until it is recognized by the immune system and forms an abscess.

Direct puncture wounds are caused by a sharp object (wire, nail, glass, etc.) that penetrates the ground surface of the foot, whether through the sole or the frog. In many cases, direct puncture wounds can be life threatening. As with many foot problems, it is often the farrier who first observes the lameness when the horse is brought out for hoof care.

If a horse is severely lame and has a foreign object embedded in the bottom of the foot, it is important not to pull it out but to call a veterinarian immediately so that a radiograph can be taken to determine the internal location of the object (Figure 2). The radiograph will reveal the depth and direction of penetration and the structures involved. This provides information about potential problems that may be encountered with the injury and provides a reference for the initial appearance of the involved structures and the location of the object. Due to the fibroelastic nature of the frog, puncture wounds to this area often seal, concealing the point of entry.

In many instances of puncture wounds, a surgical wound must be created to allow drainage from the injured area. This prolongs healing time and necessitates the use of a treatment plate. Advantages of a treatment plate include elimination of the need for daily bandaging and increased ease of observation and treatment of the affected area. Moreover, a treatment plate provides support for the foot and takes pressure off the injured area. In addition, since a treatment plate will not wear through like a bandage, the horse can often be allowed controlled exercise.

Frequently, the shoe on the horse at the time of the injury, whether steel or aluminum, can be used to attach the treatment plate; however, a straight bar should be welded into it to provide stability to the foot and plate. We prefer to construct treatment plates from aviation grade plastic which is available in a 1/4 or 3/8 in. thickness^1,2.

The procedure for constructing and attaching a treatment plate is as follows. The time required to construct the treatment plate is approximately fifteen minutes.

The shoe is placed on the plastic and outlined with a marker.


The outline on the plastic is cut with a jigsaw to create the appropriately sized treatment plate.


The plastic plate is attached to the ground surface of the shoe with "C" clamps.


Four small pilot holes are drilled through both plastic and shoe.
The pilot holes are enlarged using a 5/16-in. drill bit.


The plastic plate is overdrilled with a 3/8-in. drill bit.


The four holes in the shoe are tapped with a 3/8-in. tap.


The toe of the treatment plate is rolled with a rasp for ease of breakover and the shoe is ready to be placed on the foot.


After attaching the shoe, the foot is packed with betadine or 2% iodine saturated gauze, and the plate attached to the shoe using 5/16 x ¼ in. hex head bolts. In the case illustrated in Figure 2, a small window, extending to the solar corium, was first created in the frog with a #15 scalpel blade to allow for drainage.
 

We have found this method to be quite successful for both treatment and protection of the injured area. While a horse with such an injury should ideally be confined to a stall, this is not always possible or advisable. When it is necessary to turn a horse out, the treatment plate allows the horse to be turned out without the danger of contamination of the wound. This type of plastic is inexpensive, easy to work with, very forgiving to one's tools and extremely durable.

1 Wyndgate Farrier & Equine Supply, 15810 North Cave Creek Rd., Phoenix AZ 85032 2 Jan Young, DVM, personal communication