It's time for Tough Topic Thursday!Today we're going to be discussing big lick Tennessee Walking Horses, and how just the action of stacking and chaining is painful and detrimental to the horse.
So let's talk about how and why just the application of stacks and chains can cause pain and soring. As you can see above in the top image, a horse standing with his weight on his hoof in a resting position has a flat pastern, with no wrinkles. When he breaks over this resting position in a forward direction, wrinkles appear on the underside of the pastern.
Stacks on a TWH place a horse in a constantly over-angled position (see lines, do not be fooled by the long toe, the line is drawn on the proper angle). Besides the obvious tendon problems associated with placing a horse in an unnatural position for months at a time, the application of chains in this position exacerbates the problem. The horse's angle is broken over, and so the wrinkles on the back of his pasterns appear. Then, the chain rattles against these wrinkles, causing them to become irritated and inflamed. This happens EVEN WITH GREASE. Grease can lessen the removal of hair, but it does not remove the pain and irritation of the fragile skin.
How else can just the application of pads cause damage? Well, let's look at how exactly they effect the weight bearing ability of the hoof. In a normal horse, shown in the top image, the hoof lands heel first. The heel then opens and flexes, absorbing some of the shock before the rest of the hoof comes down and completes the absorption. The pastern and fetlock only drop to a normal angle before the rest of the foot hits the ground and the momentum of the horse passes over and begins to lift.
On a padded horse, like any shod horse, the heel cannot open and flex as much, but the issues extend far beyond that. As you can see, the pads create an extreme angle between where they strike down and where the hoof lands. This places incredible strain on the tendons in the leg as the pastern is forced with leveraged pressure to drop even farther than normal. It also, as if that weren't enough, causes a ridiculous amount of shearing force along the hoof wall and laminae, due to the angle of the stack to the hoof and the band over the top of the hoof wall. Not only is this incredibly painful, but it happens every. single. step. Once the momentum of the horse travels forward, the pad snaps forward and down onto the ground, sending a second impact shock up the lower limb, and the shearing forces on the laminae and hoof wall are sharply reversed as the horse is forced to stand on its toes again.
Imagine sticking your hand to something solid, then yanking back and force against it repeatedly. It's likely that within a few yanks your arm is tired and your skin is sore, right? Now imagine if your feet and legs felt like that with every step you took. Not very nice, is it? It's important for people to realize that even if the horse "gets used to it" or "can bear the weight", the issue isn't the weight itself. The issue is the angles and the impact on the lower limbs. I will also remind everyone that a horse has no muscles below his knees and hocks, so he cannot build strength in his lower leg to help cope with any of this.
I hope this helps to clear up some of the confusion surrounding soring and the plight of the Big Lick horse. Feel free to ask any questions your have or leave a comment below, but please be warned that hateful or rude comments will be deleted. Thanks!