All know is what I read in the American Farriers Journal; Here are some thoughts from the December issue.
Stuart Muir writes about ‘A Practical Approach to a Shoeing Prescription’ , he says that it can be useful to approach each limb as an individual case to maximize both the horses’ and the farriers’ chances for success, therefore having an evaluation protocol can be useful. Hoof capsules that are showing signs of being overloaded in certain areas can be a normal response from proximal limb alignment. Horses that have deviation in the bone column will direct the forces caused through static and dynamic loading to different quadrants of the hoof capsule. This gets back to the physics of the foot: center of rotation through palmar P3, lift of the deep flexor and ground reaction forces. He says that having a systematic approach for evaluating a horse for shoeing can be one of the fastest routes to equine soundness. What’s the system?
In an article titled ‘Halting Laminitis’ there is a picture of a radiograph of a severe laminitis “Sinker” with the caption “Subtle changes you see before rotation might include a change in morphology of the P3”. There is nothing subtle about this picture. The article talks about using cryotherapy early in the syndrome to halt inflammation but if you’re seeing bone changes that means that there was soft tissue damage well before that. This is a poor information article except for the statement that “you can’t fix their laminitis until their underlying endocrine disease or injury is controlled”.
In ‘Achieving Balance with an Artificial Hoof Wall’ there is a statement that” balance is not black and white, there is no blueprint for balance because all horses are made differently, balance is particular to the horses that you are working on”. This is not altogether true. Horses are individually different but physiologically the same. The blueprint is following the mechanical formula for mediolateral, palmarodorsal, craniocaudal and ventral balance. We don’t need to reinvent the wheel every time we shoe a horse. In this article the clinician builds up a hind foot because it is low in the lateral wall. When watching the horse move he notices that the fetlock is falling to the outside. what causes this? every foot on every horse grows out around the center of rotation (COR)-P3 line of action, this is a point just in front of the central frog sulcus in line with the first bend of the bars. Conformation of the leg above the coffin joint directs weight pushing down, the mechanics and balance of the foot dictate how the ground is pushing back up. In this case the inside (medial) wall around to the outside (lateral) toe grows faster than the lateral heel quarter because of how it’s weighted, as this area becomes longer it pushes the weight of the leg through the line of action of COR-P3 to the outside heel quarter, crushing the heel. The clinician did a great job in rebuilding the heel so as to rotate the foot back through COR to the medial toe.
In ‘Equine Thrush: A Closer Look’, Dr. O’Grady gives a good analysis of what thrush is; a degenerative condition of the central and lateral sulci of the frog. A lot of you horse owners think that organic matter decomposing in the frog is thrush but it is not. as the article points out, thrush is usually in a foot with a narrow heel and recessed frog. These type of feet are like this because they don’t weight or load the heel area enough to expand the frog and self clean. The article is confusing in that it states that by not contacting the ground, the frog atrophies, then it says that material packed over the frog creates excessive pressure. well wouldn’t that cause ground contact? Now there is a frog that is degenerative because it has been over-loaded. This foot has very little digital cushion, the foot forward to COR grows faster than or is higher than the foot behind COR, this creates a mechanical wedge in the medial or lateral plane which causes load to the contralateral heel which can cause a shearing affect just like the hind foot that I talked about earlier. O’Grady suggests pulling the shoes if possible and trimming the feet into the same plane as the frog, but this might not be successful on some feet. Consideration must be made to all of the balance aspects of the foot as they are all related to each other to make the it function properly. He suggests using a straight-bar shoe on the low sheared heel but this is a band-aid effect. It might be more prudent to balance the foot to it’s craniocaudal needs as directed by the hoof-pastern axis, remember a healthy hoof angle is a combo of the bone angle of P3 plus the palmar angle (Digital cushion and frog). It may be necessary to build the foot up and rocker it away from the over-loaded quarter.
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