Figure 1 Legend: Normal forces placed upon the hoof capsule when loaded.
The movement of the coronary band is quite visible.

Full thickness toe cracks occur due to a hoof capsule distortion. This type of crack is generally seen with a "club" foot or long toe underrun heel conformation. Both of these conditions may lead to a concavity ("dish") in the dorsal hoof wall. Eventually, this chronic bending of the horn tubules can cause a full thickness toe crack. The crack will close when weight is placed on the hoof and open when weight is taken off the hoof. The proposed mechanism is shown in Figure 1. These cracks can become a source of pain and provide an entry for infection. Treatment is directed at correcting the hoof capsule distortion and stabilizing the crack.

Lets consider the following case that previously had an acrylic repair. Figure 2A shows a full thickness toe crack. The crack is closed in the weight bearing position. Note in Figure 2B that the crack opens when the hoof is lifted off the ground.

Figure 3 shows the underrun heel with the hoof capsule being allowed to grow forward creating a lever at the toe.

Treatment begins with correcting the hoof capsule. The heels are moved in a palmar/plantar direction creating more ground surface in this direction. The solar surface in the toe area is not trimmed. When the dorsal hoof wall is trimmed back, it can be seen that the crack does not extend to the ground surface, making the use of quarter clips of no value in stabilizing the crack (Figure 4). The toe of the shoe is broadened, rolled and fitted so the inner branch of the shoe is just in front of the apex of the frog (Figure 5). This will remove the lever action on the toe and hence the forces on the crack. Note in Figure 5, that when substantial quarter clips are present, only two nails are used in each quarter.

Figure 6 shows the lateral view of the foot.

The second part of treatment is stabilizing the crack. After correcting the hoof capsule, movement in the crack may cease. If the crack still moves, some form of stabilization is necessary. Three practical methods are acrylic repair, hoof staples or the use of a metal band with screws. The operator should be thoroughly familiar with whatever method is chosen to stabilize the defect. Whatever method is used, it should be applied with the foot off the ground so the crack is stabilized in the open position. This will prevent the "pinching" affect when weight is placed on the foot. I also feel it is unnecessary to widen ("open") the crack with a dremel tool. If an acrylic repair is used, a drain should be inserted under the patch to prevent infection.

A metal band was used in the above case. The band is forged in a half moon shape otherwise if a straight metal band is used; it will diverge downwards as the hoof grows out and lose strength. The band is attached with #6 pan head screws with the hoof placed on a hoof stand (Figure 7). The band is moved up at the second reset if necessary.

It must be remembered that no form of stabilization will be effective unless the hoof capsule distortion is corrected. The hoof crack will continue to re-occur.