"My old farrier was trying to grow heel."
"Don't we need to grow heel to stand his foot up and correct the toe angle?"
Here's what I want you to do:
FORGET EVERYTHING YOU THOUGHT YOU KNEW ABOUT THE HOOF. Especially anything your last farrier told you. Please. I'm sure he was a nice guy. He may have even been well trained in farrier science. But if we're sitting here having this conversation about growing heel, your farrier was trying to fix something. And if he was trying to fix it by growing heel, he was barking up the wrong tree.
Okay, let me edify that before I get flamed up one side and down the other:
If he was growing heel to allow the sole to fill in to an adequate depth at the back of the foot, then he was barking up the right tree. If he was growing heel because the posterior internal structures were still developing and the horse needed a little extra heel height (beyond about 1/16" longer than the healthy sole plane) to land comfortably heel first, he was barking up the right tree. If he was growing heel for ANY other reason, he was on a fool's errand for sure.
Most of the time, growing heel is an attempt to create a steeper toe angle. Let me state right here that I disagree entirely with the practice of basing how much and what to trim off of the hoof by looking at the angle of the toe. But the real problem with growing heel to create a steeper toe angle is this: if the toe angle is too low, then the hoof capsule has been distorted forward. If the hoof capsule is distorted forward, the heel will have migrated forward as well. The heel purchase -- where the back of the foot lies flat on the ground -- will be pulled forward along with the rest of the capsule. At this point, growing heel will only result in the heel purchase moving even farther forward.
A really classic example of this type of foot is the typical racehorse foot. All those flat footed Thoroughbreds, right? Right, but not because they were born that way! Gallop training, it has been shown, "flattens" the hoof capsule, by pulling the toe forward, and dragging the heel along with it. (1) (Keep in mind that they were galloping in aluminum racing plates! By the way, there is a growing community in the racing industry training their horses barefoot with great success. In fact, the California Horse Racing Board was recently advised by Northern California track vet Dr. Diane Isbell that some trainers have had success training their horses without shoes and urged the CHRB to allow horses to race barefoot.(2))
So how DO we fix what has been dubbed "forward foot syndrome?"
Pretty much the same way we fix everything else. The image below illustrates how it works. We roll the toe aggressively, so that the wall can grow down without being stretched forward with every stride. We allow the sole to find its optimum depth, and we trim to that guide religiously. Sometimes a slight bevel at the point of heel purchase helps; possibly the heel bevel simply relieves some of the pressure pulling the heel forward under the foot, or maybe it encourages the foot to acclimate to a more natural plane; either way, it can be very effective with stubborn under run, or crushed, heels.
1. Peel JA, Peel MB, Davies HM, The effect of gallop training on hoof angle in thoroughbred racehorses. Equine Vet J Suppl. 2006 Aug;(36):431-4.
2. Ganz, T, Santa Anita to Replace Surface. The Bloodhorse; Feb 20, 2008
0 comments:
Post a Comment