It’s interesting how we evaluate… Things that are out of the ordinary can cause suspicion or blame. What about the horseshoe?
Some are adamantly against using a shoe at all while most will accept the application of a by-it-self flat shoe but start adding anything else to that and the red flags start to wave. Clips? ok; pads? acceptable; what about rocker shoes and acrylics? I once had a veterinarian tell me that the acrylic build I had done to a horse’s feet wasn’t natural. Are shoes natural? Even ‘Natural Balance Shoes’ aren’t natural. Natural trimming isn’t natural.
The purpose of trimming and shoeing is to create equilibrium in the feet for the health and performance of the horse. If the feet are growing out properly they are functioning properly and so is the rest of the limb.
Now….. how the foot grows out is largely related to the position of the leg and the weight of the horse above and the ground reaction forces from below. The growth areas of the foot that are weighted the most, grow the least because they are under compression and are not getting the blood supply of the non-compressed areas. All of this is very sensitive to Center of rotation (COR). COR is in the end of the short pastern bone above the coffin joint. This area is like the axle on a wheel and it is around this that the foot and leg rotate. another big player is the deep flexor tendon which attaches to the bottom of the coffin bone. Tension in the deep flexor rotates the foot forward which weights the toe. Lack of tension can derotate the foot back which weights the heels.
Here’s the scenario: A horse presents a lameness and his feet are in sorry shape. Corrective shoeing is part of the therapy. These feet lack hoof mass, heel to toe balance and enough angle for proper foot-leg function. So to get these things back into equilibrium it takes two tubes of acrylic, wedged aluminum shoes and pads. A few days later the horse is moving better. At week two the owner is thrilled because the horse is moving like a champ. At week three there is a slight decrease in motion and at week four the horse is starting to show a little lameness again. The owner needs advise so she consults her trainer who convinces her the horse doesn’t need all that stuff on his feet, her shoer wouldn’t do that. The owner waits until week six to have a recheck with the veteriarian. The vet notices that there is considerable grow-off but doesn’t really understand why the horse got better than worse again. In the meantime the owner is convinced that the shoeing is causing the lameness. The vet wants to keep the owner happy and also try to look like he knows what he is doing so together they are going to reinvent the wheel. What really happened?
Getting the feet back in balance achieved the mechanical goals needed to treat the lameness but it accelerated the growth in the healthier part of the foot around COR. This recreated the mechanical block. So what do you do? Don’t panic.
Reorganize the feet. trim through what acrylic is not needed anymore or add on to areas that need it. Measure the hoof-pastern axis to determine if wedges are still needed. as the feet evolve their needs will change with every shoeing. It doesn’t take much to get a foot out of balance, 5 mm of extra or lack of horn can cause a 2° change to the bottom angle of the foot. The foot doesn’t have to have a lot of change, just enough can upset it. These feet need to be on a shorter shoeing cycle until there is a more uniform grow-out. Use what is needed to create balance. When people start demonizing our tools like acrylics, pads, shoes or whatever and say we can’t use them it limits our options. Don’t throw the baby out with the bath water!