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Egg Bar Shoe Seminar in England
Dr. Sven Kold of the Animal Health Trust in Newmarket introduced a special presentation on egg bar shoes at the National Master Farriers, Blacksmiths, and Agricultural Engineers Association Annual General Meeting in Stoneleigh, England in May. Dr. Kold has long been a proponent of the egg bar shoe for navicular disease, and has written extensively about his research using the shoe.
Kold stated that 18 horses competed at the 1984 Olympics in Los Angeles wearing egg bars. He said that the 1986 World Championship Dressage Team horses from The Netherlands were all shod with egg bars.
In answer to those who would argue that the egg bar is a difficult shoe to keep on a horse, Kold stated that the horses would lose any shoe that was nailed onto their feet, because of the poor quality of horn often found on horses that need egg bars.
"Lost shoes aren't a big problem," Kold stated calmly. "The shoes are used on most types of competition horses. Cross-country eventers land on an uneven surface, which is not good for an egg bar, nor are the shoes well suited for racers in fast work."
Getting down to business, Kold warned farriers that it is important to make sure that the foot has been trimmed far back enough, particularly in the hind feet, before applying an egg bar shoe. "I am seeing egg bar shoes that are fit well in the heel but so much toe has been left that it is hard to break over," Kold admonished. "A long toe defeats the purpose of the shoe." He suggested rolling the toe behind to prevent forging.
Continuing, Kold prescribed an egg bar shoe for heels that are "collapsed" forward (similar to what Americans call "rununder"). Kold asked that the shoe be fit wide from the broadest point of the foot back, with the nails as far forward as possible. He said that he preferred two nails per side, for as much heel expansion as possible.
For fit at the heels, Kold suggested holding a ruler down the back of the bulbs of the heel. If it touches the back of the egg bar, that's okay. If you can see daylight between the inside of the bar and the bulbs of the heels...it's not okay.
Kold commented that he did not use wedge pads in conjunction with the egg bar. He said he feels wedges are only a temporary aid when used with egg bars.
In cases of medial-lateral hoof imbalance, Kold prescribed that farriers "set the shoe where you'd like the foot to turn to. A little narrow on the flared side, wider on the under side. We had an egg bar on a three-year-old Thoroughbred with pain in the lateral branch of the suspensory ligament at the fetlock. The problem was due to no support on the outside heel, which was collapsed. The inside heel was okay, so we set the egg bar wide on the outside heel, tight on the inside, and encouraged the foot to expand to the outside."
For a case with sheared heels, Kold gave the example of a 600 kilo (13,000 pounds-plus) warmblood with tiny feet. A block on the inside heels made the horse comfortable. The shoe was fit so the horse was actually standing on a larger foot surface, with a narrow outside. There was immediate improvement, although Kold commented that the horse will always need an egg bar shoe. The regular farrier was able to resume shoeing the horse.
Kold and (former) Animal Health Trust farrier Ron Ware FWCF worked together to shoe a horse with an egg bar for the audience. They commented that the center of gravity of the horse must correspond to the center of the shoe so that the weight of the horse is never further back than the back third of the foot. The egg bar shoe adds 25 percent more groundbearing surface to the foot.
In designing the shoe, Ron Ware commented that the heels must be directly in line with the breakover point of the foot. "The heels have to go forward," he stated. "They are governed by the growth of the coronary band." In general, Ware advised, farriers should ignore the height of heels and walls when balancing a foot.
Ware's formula was to double the width, add 1 1/4", plus the width of the bulbs of the heels, to figure the length of steel needed. He said that you must also factor in fullering, which alters the final length, but that this is a trial-and-error method, "until you get the hang of it." The demonstration horse required a bit more than 16 inches of steel.
While Ron was working at the anvil, Dr. Kold asked academically, "When does the flexor tendon take over from the extensor? And vice versa?" He said that the foot actually flutters in flight. When flexed, the weight of the heel has 25 percent more material when shod with an egg bar, and the added weight throws the foot higher in its arc.
Kold said that after having a horse reshod with an egg bar, an owner commented that his horse had better length of stride but higher action. Kold wondered aloud if the effect was really the added weight of the shoe or if the horse was just more comfortable.
Meanwhile, back at the anvil, Ron warned that farriers should not make the toes of egg bars too broad. "They should be widest at the heels," he prescribed. "Turn the toe tighter than you would for a normal front shoe."
To scarf the shoe for the welding point, Ware, who is right-handed, used the chainlink method. He hit the shoe and turned it under with the first blow, then laid the second blow on the other scarf. "The thinnest part of the shoe cools first," he said, referring to the scarf. "And the part of the shoe under the scarf that is in contact with the anvil will be the first part of the scarf to cool."
When ready to fuller, Ware warned farriers not to seat the shoe around the toe, because the whole shoe will collapse. "Don't run the fuller too far forward or too coarsely, because you'll have trouble with the toe nails," Ron pointed out." He rolls the toe so he leaves the toe area flat. "Fullering won't help with grip if you've rolled the toe," he grinned.
On the bar, Ron recommended seating over the area, so that there was no frog pressure. He also recommended seating the shoe behind or between the second and third nail holes.
When nailing close to the toe, Ron said that if the horse had a broad foot, you should nail further back to restrict expansion. The heels are free to float because they're unrelated to any other structure in the foot and can do no harm no matter how much they expand.
British farrier Billy Crothers assisted Ron in nailing on the finished shoe, as the demonstration ended. Several hundred farriers then poured out of their seats and all tried to pick up the foot at the same time.
This article originally appeared in Hoofcare & Lameness: The Journal of Equine Foot Science and is available for your personal use only. Re-publication is prohibited without the express written permission of Hoofcare & Lameness.
Detailed information on this and many other hoofcare topics can be found in Hoofcare & Lameness publisher Fran Jurga's award-winning guide to hoofcare, "Understanding the Equine Foot".
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