Negative pressure HB shoe, note the tong depressor passing between frog and plate.
The author uses a four clipped shoe with a beveled outside ground edge ( bodemeng gerandert ) and a negative pressure frog plate in the treatment of distal phalanx fractures. One of the clips is placed forward of the widest part of each side of the foot and one is placed behind of the widest part on each side.
Playing around with the right depth of the frog support plate is, as can be seen from the above, essential to the appropriate use of a heart bar. By using a 6 mm thick frog plates in combination with 8 or 10 mm thick shoes, the farrier has a wider range of depth adjustment as with a ready-made or full thickness frog plate shoes.
Heavy or hard working horses however may bent even the best welded frog plate. To prevent this from happening, having two arms running to the inside rim of the shoe from the tip of the frog plate will greatly reinforce the correct frog plate depth and alignment. This sort of frog plate has variously been called a mercedes , star or spider plate. These type of frog plates also make it easier to hold in place additional silicones, like premium rehe, so as to increase the support in the palmar/plantar region of the foot (laminitis e.g.).
The use of aluminum, readymade “mercedes” shoes, has the advantage of lightness and 10 mm thickness. This last characteristic permits the floating of one , or even both, of the heels by thinning the upper surface of the shoe at the heels, while the shoe will remain stable enough thanks to its star-shaped frog plate.
Appropriate use of HB shoes, a concise guide:
Positive pressure ( if tolerated):
Laminitis, Hoof wounds, Quarter cracks, Onicomycosis with extended hollow walls.
Neutral pressure :
Underrun and weak heels, the above conditions when positive pressure is not tolerated.
Negative pressure :
Navicular bursitis, some forms of podotrocleosis (Deep digital flexor tendon lesions in its distal part e.g.), Distal phalanx fracture.