As long as man and horse have been paired for work or pleasure, protecting the hooves of a horse has been an important part of horse caretaking. While a hoof is formed of a hard, bony material that is capable of withstanding a relatively large amount of stress, horses are made to travel, work, and perform under conditions not present in the wild.
The most widely used and recognizable device for protecting the hooves of a horse is the conventional metal horseshoe. The shoe is formed from a piece of metal that conforms to the shape of the bottom edge of the hoof. The shoe can be made of aluminum, titanium, or steel, and contains a number of openings along the curved centerline of the shoe. Nails are driven through the openings in the shoe and into the hoof to secure the shoe to the bottom of the hoof. When properly shod with shoes of this type, the hooves of the horse retain their shape and the edge of the hoof is protected from chipping or cracking.
Nevertheless, although the conventional horseshoe is easily manufactured and reliable, it is not without various shortcomings. As the shoe is normally attached to the hoof by a number of nails driven into the edge of the hoof, the nails may work loose over time for a number of reasons. When the nails loosen, it is likely that during the normal course of activity, the shoe will fall off the hoof, i.e. the horse will "throw" the shoe. Also, on occasion, the horse may step on a shoe secured to a front hoof with a hind leg, causing the front shoe to be "stepped off". In either situation, the hoof is left completely unprotected and may become chipped if the shoe is not replaced. Many times it is impossible to replace the shoe as there are usually no nails available to resecure the shoe on the horse. Also, the original shoe may be unusable as it has become lost or twisted beyond repair. In most cases, the horse must be led back to a stable for the shoe to be replaced by a farrier.
Furthermore, when a horse has medical problem with a hoof, the horse is not able to wear a conventional horseshoe during the treatment of the condition. This insures the conventional shoe will not exacerbate the condition and enables any veterinary treatments to be placed on the hoof. However, without a shoe, or some other form of protection on the hoof, the hoof is left unprotected and may become injured further.
Recently, certain devices have been developed to address the problems regarding thrown shoes and protection of the horse's hooves. Furthermore, some of these devices are able to protect the hoof even during veterinary treatment of the hoof. Many of these newer shoes are formed of, or incorporate elastomeric materials, such as polyurethane, because of their attractive combination of durability and the ability to dampen vibrations or shock.
One such device is the Shock Shod Horseshoe manufactured by Shock Shod International, El Segundo, Calif. This horseshoe consists of a polyurethane shock absorbent layer overlaying an aluminum support bar. When placed on a hoof, the aluminum bar provides a rigid protective layer directly beneath the hoof in the same manner as a conventional shoe. The polyurethane layer located beneath the aluminum bar contacts the ground and reduces the stress exerted on the hoof and leg of the horse while walking or running. The shoe is secured to the hoof by the insertion of a special shoeing nail into each of a number of openings in the shoe, much like a conventional shoe. The design of the openings retains the head of each nail driven through the openings to prevent the nails from coming loose, thereby preventing the horse from throwing the shoe.
However, while providing an alternative to the conventional shoe, the Shock Shod shoe does not eliminate all of the problems associated with the conventional shoe. As the Shock Shod shoe is still secured to the hoof by nails, the shoe still has all of the aforementioned drawbacks associated with the conventional shoe arising from the use of the nails to affix the shoe to the hoof. Also, the use of the nails to secure the shoe to the hoof prevents the Shock Shod shoe from being usable during the treatment of a medical condition of the hoof.
Furthermore, the Shock Shod shoe has other shortcomings associated with it that are not present with a conventional shoe. The Shock Shod shoe requires that the polyurethane layer be securely affixed to the aluminum support bar to form the shoe. This construction necessitates a complicated and costly process in which first, the bar is properly shaped to fit the hoof and retain the polyurethane layer, and second, the polyurethane layer is extruded over the bar. In short, the Shock Shod shoe, while superior in certain ways to the conventional horseshoe, has a complex construction that does not completely eliminate the problems associated with the conventional horseshoe.
Another prior art device designed to provide an alternative to conventional horseshoes and capable of use in certain medical applications is the Easyboot.RTM., manufactured by EasyCare, Inc., Santa Fe, N. Mex. The Easyboot.RTM. is a boot for a horse that consists of a base integrally formed with a wall that extends upwardly along the periphery of the base. The wall covers the hoof almost entirely and is flexible to allow the boot to adapt to the unique shape of the hoof of any horse. The boot is secured on the hoof by a closure mechanism that negates the need for nails to secure the boot to the hoof. The mechanism includes a ski boot-type clamp disposed on the front part of the wall of the boot and a closed loop of a resilient cord that passes through openings in opposite sides of the wall of the boot. To secure the boot on the hoof, the cord is first placed within a groove on the interior of the ski boot clamp. The clamp is then pressed downwardly to close it. Closing the clamp pulls the cord forward and, as the cord is retained in the openings in the wall of the boot, it thereby constricts the sides of the wall of the boot tightly against the sides of the hoof.
While providing durable hoof protection, the Easyboot Easyboot.RTM. does present certain problems when in use. First, the ski boot-type clamp utilized in the closure mechanism exerts a large amount of pressure on the front of the hoof. This pressure leaves marks on the hoof, causing the hoof to become irritated, and possibly weakened, at that point. Also, the wall of the boot almost completely encloses the hoof. As the boot is formed of an impervious elastomeric material, this design prevents air from circulating around the hoof. When the Easyboot.RTM. is used on a hoof undergoing treatment for a medical condition, the lack of circulation created by the device may exacerbate or cause additional medical problems with the hoof.