Mark_Gough wrote:Rick brings up some good discussion points. It is my hope that you have time to respond to his post.
Thanks again,
Mark
Rick's questions indicate that I have not been clear enough about the first of all steps working on chronic rotated laminitic horses. This is the often discussed "derotation/realignment" part. I noticed some have trouble with the wording "derotation". Frankly I don't care at all how it's called as long as the concept gets through.
On a rotated P3 we can not put screws in the hoof wall and attach P3 back to the wall as a means of derotation. For one because the hoof wall grows down but P3 stays in place relative to that hoof wall.
If we think hard enough we'll see that there is no way to get P3 back aligned with the dorsal hoof wall once it rotated. What we're left with is a P3 that points down leaving a lamillar wedge of pus, stretched and/or destroyed lamillae and what else dorsally. P3 pointing down puts pressure on the underlying vessels, limiting sole growth. The first and last protection P3 has.
If we step back a bit from this problem of not being able to derotate P3 within the hoof capsule, we might see that there is another way to derotate P3. We cán position the
entire hoof capsule in a way it leaves P3 in a normal position relative to the horizontal. This usually leaves the hoof wall with a funny looking dorsal hoof wall, which is of no importance at all at this stage. As long a proper shoeing prevents the toe from being a break over lever leave all the toe as much as possible. Don´t worry about how it looks. In fact working on that issue would be more like working on a symptom rather than a cause.
Shoeing laminitic horses is about P3 guys NOT the hoof capsule. When discussing derotation we're discussing derotation of P3 by means of changing the support surface of the hoof capsule. Rotating the hoof capsule obviously also changes the position of P3 in that hoof capsule as long as the lamillar bond is not fully destroyed as in sinkers. P3 and the hoof capsule are connected through a lamillar bond even in lamitic cases, the bond there is in serious jeopardy but often strong enough if we help it.
The way I see it shoeing laminitic horses is nothing more than counter acting the forces at play. We are no healers, we're mechanics. The healthy foot is a surprisingly delicate co existence of forces and counterforces all acting upon and within the foot. I call that a matrix (and hope it clarifies what I mean in stead of diffusing it

) That matrix handles all forces, DDFT pull and the navicular pulley, just as it handles ground reaction forces, weight of the loaded foot, the lamellar bond and much more. This delicate matrix is virtually undestructable when that matrix is well maintained. But when one of the parts is destroyed or damaged the rest can not cope anymore.
Laminitis damages the bond between P3 and the hoofwall, why and exactly how is for researchers not us. The result however is obvious the matrix is destroyed, in this case DDFT pull has no counter force anymore and P3 is pulled away from the wall. The front end of P3 (apex) crushes everything underneath, the vessels and given time the sole that will stop growing because of lack of bloodflow through those crushed vessels for one. But more than that happens. The rotated P3 allows for rapid heel growth, reducing the counterforce of the ground working on the frog and sole. The rotated P3 also compromises bloodflow through the coronary artery because the extensor proces is pushed forward (dorsally) when P3 rotates.
I am absolutely convinced that this mechanical result of laminitis is the one and foremost issue we need to deal with.
Over the years there have been several approaches to address the devastating mechanical result of laminitis. I guess two of the most well known are the approach by Burney Chapman and the one Ric Redden worked out. Both are different. But both seem to agree that derotation/realignment is vital.
For me over the years I tried everything, even barefoot approaches. The system I work with is what has given me the highest succes rate of all the systems/protocols I tried.
In short I think you need a protocol that leaves the hoofwall and works towards hoofwall integrity; experience taught me I needed a system that would normalise the position of P3, relative to other structures within the hoofcapsule; for that I feel you need to reduce DDFT pull acting on P3 and the lamillea; further I realise that damage to the lamillar bond leaves P3 less stable within the hoofwall, in a attempt to provide more support frog/sole support is needed.
On my quest looking for reducing break over forces through this very same bulletin board I ran into banana shoes. Over the years I have used that protocol in a lot of situations laminitis for one. But the only advantage a banana shoe has over other means of break over is the it allows the horse to play with it's palmar angle. All other methods of easing break over bring back break over but do not allow that play. Why that play (being able to rock forward and rock back) appears important I don't know. I do now that just raising heels to reduce DDFT pull does not work in severe cases. The raise needed is so high you just crush heels. Steps to limit that heel crushing like heartbars appear to just further compromise bloodflow because the support needed to really take load from the heels is so big it just crushes the frog and sole, especially in laminitic horses that had weak heels to start with.
Some by the way feel that weight is an issue in laminitis. I don't know but I do doubt that statement. In my view weight is a friend rather than a foe. Break over forces are the main problem, not the weight as such. I don't have scientific proof and I have been wrong before. But reducing weight acting upon laminitic feet is no help in recovery at all. I think its fair to say that by now.
I hope this clarifies some of at least my thinking up to now on the mechanical effects of laminitis.
Ronald Aalders