Originally Posted by MicKey73
Hi! One of the event prospects I just went to see and ride has pads on her front feet.
Is this a normally used way to grow heels?
Let's presume the owner is being honest and that the farrier's reason for installing the front pads is to address a "low heel" issue.
If you replace the word "normal" with "common", then yes... it's a "commonly" used way to "grow" heels.... and no, for the most part, it doesn't work.
Let's talk about why and what "low heels" really means.
The vast majority of "low heeled" horses have a congenital defect called "under-run heels". The heels aren't really "low" in that they lack length. They appear "low" because the horn tubules at the heel grow and collapse (bend) at a more acute angle than those tubules originating more anterior the hoof capsule. A common, albeit somewhat arbitrary rule is... if the posterior horn tubules at the heel grow at an angle that is five degrees or more acute than the horn tubules at the toe, the horse is classified as having "under-run" heels. It's not a great definition, but it's a fair rule of thumb... or rule of "heel" as the case may be.
To address the mechanical distortion associated with under-heels, the hoof, and particularly the heel region, is trimmed in an effort to bring the "base of support" back under the vertical axis of the limb. This results in the "low heels" that owners so often complain about.
This is an important point. The farrier isn't trying to "lower" the heels. He's trying to move the heels "back" in an effort to improve balance around the center of articulation. Correct dorsal/palmar balance is more important than heel tubule length. The farrier can compensate for the resultant loss of heel length (e.g. Wedges), but without trimming those under-run heels to a shorter length he cannot otherwise move the base of support.
There are two common reasons for a horse to present under-run heels.
The first is excessive capsule length. Poor maintenance can, on some horses, result in a foot that "runs forward" under load. The heels drive forward under load during the landing phase of the stride. The entire foot, beginning with the toe, is dragged forward again during the breakover phase of the stride. As the foot grows in length, the leverage/load force becomes greater, bending the horn tubules of the heel and resulting in a greater disparity of angle between the heels and the dorsal wall.
This first case of "under-run" heels really isn't "under-run" heels at all. It's capsular distortion associated with poor hoofcare and can usually be corrected with proper trimming.
This first case is also comparatively rare.
Let's talk about the second and more common case... congenital under-run heels.
The second case is a matter of debate but at least does center around the premise that the issue is congenital/conformational. Congenital/conformational associated under-run heels cannot be corrected.
In the congenital case, the horn tubules of the heels will present forward running distortion nearly at their origination point. Under microscope, these tubules will appear "bent" in the first few millimeters of growth. No one appears to know if those tubules are bending because of load force associated with conformational imbalance or because they are simply "weak" as compared to the tubules more posterior the heel area of the coronary corium. In my personal view, the causal factor is variation in tubule diameter, strength and growth direction at the origin of the coronary.
Either way, the farrier can only compensate for the defect, not correct it. Pads are the most common approach to compensating for the weak/bent tubules.
Thoroughbreds are notorious for this problem and particularly difficult to manage. It also places the farrier in a poor position. If he trims the heels in an effort to balance the base of support around the COA, the owner complains the heels are too short. If he leaves the heels alone, they distort forward, leaving the horse in dorsal/palmar imbalance and increasing the risk of bruising at the heel buttress.
A secondary issue for horses presenting under-run heels is phalangeal alignment. Bringing those heels back (shortening) also means reducing the ventral angle of the distal phalanx relative to ground parallel. That reduced angle can mean a "broken back" pastern alignment. Again, wedge pads, often with frog support, are utilized to realign the phalanxes. If the heels can be brought back without compromising phalangeal alignment, a flat leather pad may be employed to reduce load impact force at the heel buttress and the entire hoof capsule. I've done the mathematical analysis of pad depth effect on impact force reduction over the increased "cushion" distance a pad provides and found the reduction to be surprisingly small. It helps, but not much.
So, there you have it. Pads won't, in my view, help a horse with "low heels" grow more heel because heel growth isn't the problem. The problem is "direction of tubule growth/distortion". Pads help the farrier manage the problem by addressing the mechanical distortion and load balance.
Do these horses require shoes and pads for life? As always, it depends. It depends on the owners use and performance expectations of the animal and the magnitude of the defect.
Either way, barefoot or shod, padded or not, resultant weak tubules or simply conformational imbalance, horses presenting true, congenital under-run heels are what they are and the owner and farrier are left to manage the issue as best they can.
There are two easy ways to avoid the problems associated with chronic, congenital under-run heels in horses.
First... don't breed them.
Second... don't buy them.