A Possible Alternative to the
Wooden Shoe in Selected Cases
Stephen E. O’Grady, DVM
While at the annual AAEP Convention in Denver, CO last year, Monty Ruetenik from Soft-Ride gave me a few pairs of a new shoe they are developing. He called it a Center-Loading Accommodative Shoe and it possess many of the same mechanical principles as the wooden shoe although perhaps to a lesser degree. The circumferential breakover, especially at the toe, will be able to decrease the forces on the peripheral hoof wall and move the load axially under the distal phalanx. The shoe is made up of two polymers which are elastomeric urethanes. The brown polymer on the ground surface is a 65-durometer shore A, which may aid shock dissipation and help with wearbility.
The black polymer on the ground surface is a 17,000 tensile strength urethane with a hardness of 65 shore D scale creates a wedge shaped non-deflecting base for the foot. The perimeter of the shoe can be easily modified with an angle grinder or a belt sander to enhance breakover and a shallow trough can be created in the ground surface under the distal phalanx to accommodate a mild sole prolapse. The shoe is easily attached using nails, screws and or just casting tape.
The mechanical components of this shoe would be similar to the wooden shoe. Briefly, it has the ability to redistribute the load (weight) evenly over the solar surface of the foot due to its flat solid construction. Impression material can be added to the solar surface in the palmar section of the foot if desired to increases the surface area of the foot further. Breakover and mild heel elevation is fabricated into the shoe and the beveled perimeter of the shoe appears to decrease torque on the outer hoof wall by moving the ground reaction force axially. Furthermore, the beveled perimeter of the shoe also concentrates the load (weight) under the distal phalanx due to the solid base of the shoe.
This was a young thoroughbred horse with acute laminitis seen as a referral a few days post vaccination. Horse showed an Obel grade 3 lameness and positive hoof tester response involving the sole dorsal to the apex of the frog. The lateral radiograph showed a hoof wall to dermis ratio of 1:2 which indicates laminar swelling and is consistent with laminitis. The horse had relatively good hoof conformation although the toe length was somewhat long. The shoes were removed, the toe length was reduced using the nippers in a vertical plane just dorsal to the sole-wall junction. This method decreases the toe length but leaves all the mass on the solar surface of the foot. I modified the perimeter of the shoe using an angle grinder which eliminated some of the ledge and created a more bevel to aid breakover. I attached the shoe to the foot with 2-in casting tape which allows easy removal to examine the foot and immediately replace it with another roll of casting tape.
Picture show additional bevel (red arrows) created in shoe…shoe attached with 2-in casting tape.
The horse immediately became more comfortable and continued to improve over the next few days. The medication was slowly reduced, the horse was confined to the stall with periods of hand grazing for 30 days and then was shod with conventional shoes.
The second case was a metabolic horse with recurrent laminitis. The horse was barefoot and had adequate sole depth/thickness. His feet were trimmed appropriately and this shoe was applied as described previously. He became more comfortable immediately and with the proper attention to diet and medication to treat metabolic disease…the shoes were removed after a few weeks and the horse was sound.
This was an interesting case…chronic foot soreness with 6 mm of sole depth. I generally try and rehabilitate these cases with some time off and either barefoot or a wooden shoe for a few weeks. This horse also had low heels with the frog prolapsed below the ground surface of the foot. I reduced the leverage from the toe as described above and applied a pair of these shoes. I spread a light coating of Equilox® on the outer hoof wall and then secured them with 2-in casting tape. However, in this case, influenced by my good friend and farrier, Derek Poupard CJF, DipWCF, I did not encase the foot with casting tape. As the horse had low compromised heels, I removed the cast material from either side of the bulbs of the heels so as not to inhibit any movement of these structures. The shoe was held in place by the rim of the cast around the perimeter of the shoe. Radiographically, at 5-weeks the horse had 12mm of sole on one foot and 14mm on the other foot.
Video shows the heel section of a casted foot being removed
(courtesy of Derek Poupard)
I have had good success with the using it in a variety of foot problems and the ‘SoftRider’ shoe has some of the same advantages…two being the solid foot pad and the circumferential breakover. Obviously in a chronic laminitic case with significant displacement of the distal phalanx, the wooden shoe would have distinct advantages by being able to address / alter the biomechanics by the thickness of the block. Although I have only used this shoe on a limited number of cases; it could be considered another good farriery option.
Disclaimer: Dr. O’Grady does not have any affiliation or financial interest in either Soft-Ride or Hoof Cast. I use and describe various products and or methods that I feel may be useful to the equine industry.