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Natural Balance Hoofcare
| Natural Balance Shoeing |
| (Trimming & Shoe Placement Suggestions) |
Special Notice Before Beginning Trimming the Sole Too Close Our research has shown that when a foot is routinely trimmed too close at the toe each time the horse is shod, P-3 seems to settle some and the horse can be 'off' for a few days. It is our belief that the sole ridge (callus) plays a major role in supporting P-3. When the sole ridge is over-trimmed, the laminae attachment of P-3 at the distal border may be compromised, which can allow the hoof wall to migrate forward, much like in laminitis. The settling of P-3 within the hoof capsule causes a vertical deformity in the hoof wall at the hairline. A common practice for farriers is to trim the toe and leave the heels in order to achieve pastern alignment.¹ However, when farriers trim the sole close at the toe to raise the foot angle, the heels are frequently left too long. With the weakened laminae attachment at the distal border of P-3, the hoof wall and the long heels will migrate forward, allowing the entire hoof wall to migrate ahead of P-3. This can be easily seen when viewed from the bottom as well as when viewed from the side. Heel First Landing Slight heel first landing is common with feral horses as well as sound domestic horses; therefore we find it to be optimal for Natural Balance principles. Research has shown proprioceptors in the calloused portion of the frog buttress.² This supports and suggests that heel first contact may be important. Later research of Dr. Barbara Pages showed that when the breakover was placed ¼" ahead of the tip of P-3 and the heels were trimmed so the frog buttress had contact with the ground, pastern alignment improved and the navicular bone became more vertical.³ These combined hoof preparation techniques will routinely initiate a heel first landing. In retrospect, this will help to avoid stumbling, forging, interfering and has shown to improve hoof deformities that lead to heel soreness, contracted heels and navicular disease tendencies. Special attention must be given when preparing the foot for shoes. For farriers shoeing horses in the field without radiographs to properly position the shoe, the following instructions are important to get the best results. Hoof Preparation Procedure For Shoe Application Start by identifying the true apex of the frog, either by probing or by removing a small amount from the tip of the frog pad if necessary. At that time you should get a mental picture of where the live functional sole is for that part of the foot. Next, remove all of the chalky sole material next to the hoof wall at the widest part of the foot. (Fig. 1-A & 2-A) There will often times be small cracks in the chalky sole material. The sole material that is left should have a waxy appearance and will not contain of small cracks. If there are any doubts, return to the frog apex and work your way back out to the outer edge of the sole, searching for chalky layers as you go. With those feet that are very difficult to decipher the difference between live and dead sole, take the conservative approach and do not get too close. It's better to leave it too long than too short. Your goal is to clearly identify the live sole ridge (callus), which is the waxy surface seen once the crumbly, chalky material of the sole is removed. (Fig. 3 & 4) When you exfoliate the rear of the foot with your knife, again, remove the chalky material and leave the waxy, functional, live sole. Be careful to leave as much of the upright, healthy bars as you can.
When the foot is properly exfoliated, you should notice the slightly raised area of the sole next to the wall. (Fig. 3 & 4) That raised area is the sole callus and should blend in gradually to the wall with no ledge. Once you become familiar with the sole callus, you can clearly see the position for breakover on the sole. To help you find the breakover position on the sole, lightly move your thumbs forward from the frog apex to the medial and lateral toe quarters. (Fig. 5) A slight depression will be felt on the sole. At the cranial aspect of that depression is the inner edge of the sole callus. A line drawn across the toe at the inner edge of the sole ridge (callus) is where breakover should be. (Fig. 5-A)
Keep in mind, the four corners of the coffin bone are the part of the horse's anatomy we are trying to put in balance with the ground. The objective is to prepare the hoof wall in a manner that will allow this to happen. It is best to prepare the back part of the foot first. From a line drawn across the foot at the around the widest part, rasp or nip the heel so that the height of the wall behind the widest part of the foot in the heel quarters is approximately 1/8" higher than the waxy live sole. (Figure 6 & 7) Each side of the hoof wall in the heel region should be prepared similarly.
The next step is to prepare the front or toe area. Remember that self-maintaining feet of domestic or wild horses are found to have the sole on the ground inside the hoof wall in this toe quarter area. (Fig. 8) Bring the wall down to meet the sole by rasping into the sole callous at the two toe quarters, until flattened areas appear equally on both sides. (Fig. 9) The width of the flat sole callus, measured from the laminae inward, should be approximately ¼ inch. This will ensure that there is optimal sole thickness below P-3 for protection and support. This will also accurately balance the front of the coffin bone to the ground from side to side when the live sole contact with the ground is the same. Farriers experienced in this technique find some variations in this measurement of sole callus width in feet that are affected by previous trimming practices, individual hoof types, or extremes in general hoof condition. The bottom surface of the foot is finished flat when the foot is prepared for shoeing (not relieved in the quarters as is the case when left barefoot) and is hot-seated if possible.
Flares should only be removed from the mid portion of the hoof wall to the ground. (Fig. 10) The amount of wall that is rasped away should never exceed the outer layer (stratum externum). When the white zone appears at the ground level, wall flare removal should cease. Once the shoe is applied and the wall extends beyond the shoe at the toe, remove only what is beyond the shoe by under-cutting (with a rasp) at approximately a 45° angle. (Fig. 10-A) With extremely flat feet, flares have the wall pulled away from the sole at the ground level. These flares should be removed in a very abrupt, dubbed fashion.
Shoe Placement and Application Shoe selection is important if you wish to meet the natural breakover requirements. Wide-web rim type shoes work best for easy modification. The outer rim is normally tapered-in somewhat to the nail groove, which is helpful and somewhat mimics the way the bare foot naturally wears. That same feature is equally helpful at the toe where the shoe is squared somewhat and positioned on the foot so that breakover is in its natural place. The shoe should be fitted to the foot so the breakover point of the shoe fits directly over the back edge of the toe callus at the center of the toe. The heel of the shoe should extend to the full length of the frog. A good reference for that position is the back of the crease in the central sulcus. Radiographs can be used to determine the natural position for breakover,³ as described by Dr. Page in the 1999 AAEP Proceedings. When pre-made steel or aluminum Natural Balance Shoes™ are used, the same criteria for shoe placement for breakover, as well as heel length, should be followed. The Natural Balance Shoe™ instructions (available from the "Downloads" page) suggest a varied distance from the frog apex to the inside edge of the shoe for placement. (Fig. 11-A & 12-A) Regulate that distance with the heel position. Remember, the hoof preparation is exactly the same for both modified and Natural Balance Shoe™ application. Again, the breakover point is at the inside edge of the sole callus in the center of the toe, approximately 1 1/8" ahead of the frog apex. (Fig. 11-B & 12-B) Do not allow sole pressure between the shoe and the sole callus. Hot-seating will ensure that sole pressure does not occur. The back two-thirds of the shoe extends to the back of the crease in the central sulcus of the frog.
These shoe placement guidelines are for normal hooves, in the field, when no radiographs are used. Radiographs should be taken for horses that have lameness issues such as laminitis, navicular disease, or when severe hoof deformity is present. Radiographic Method ³ A thumbtack is inserted at the true apex of the frog, and a metallic wire is taped to the hoof capsule along the dorsal hoof wall with the proximal end of the wire at the edge of the hoof capsule at the coronet. This location is palpated as the junction between the skin and the hoof capsule. Both front and hind feet are placed concurrently upon wooden blocks imbedded with a horizontal radiopaque wire. Feet are positioned so that the third metacarpus or metatarsus is perpendicular to the ground. Efforts should be made to have both forelimbs (or hind limbs) equally weighted. Lateral-medial radiographs are obtained with both bulbs of the heel being parallel to the x-ray beam and the radiographic cassette touching the hoof capsule.
Using the first radiograph of each foot, a line is drawn on each radiograph from the tip of the third phalanx perpendicular to the ground. A second line dorsal and parallel to the first line is drawn at the following distances: 0.4 cm for horses 200-300 kg, 0.5 cm for horses 300-400 kg, 0.6 cm for horses 400-500 kg. The distance from the thumbtack to the most dorsal line is then measured. (Figure 1) This same distance is measured on the solar aspect of the hoof capsule from the thumbtack dorsal toward the white line. A perpendicular line is then drawn between the medial and lateral walls of the hoof capsule at this location. This line indicates where breakover of the shoe is placed. Hoof preparation is the same as with the shoeing of normal feet. - Click Here for a complete section on "Radiography Method" (with illustrations) provided by Dr. Barbara Page DVM |
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This page was last update on 8/22/01. Copyright © 1998 Wild Horse Publishing & Equine Digit Support System, Inc.. All rights reserved. Terms of Use |
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