Digging Deeper into Navicular Syndrome
To get you thinking I will ask a question that seems so simple but has the answers to most navicular problems all rolled into one.
Why do Navicular Horse, club footed horses and foundered horses have similar strides and discomfort when turning sharply, the answer is they have the same problem.
So if a badly foundered horse has trouble turning on the spot like a navicular horse and a club footed horse favours the opposite leg to the club foot one so much that the hoof appears overworked and flat, what is the link?
I found the answer to all of these hoof problems from watching horses that could not develop good frogs even when they were doing endurance distances. If these horse's were getting the normal work load for a horse on a daily basis why could their feet not achieve good frogs. There had to be a mechanism that was either painful to the horse or changing the horses movement. The question was then what is the connection between a horse that has very similar feet but cannot use one to its true extent.
The answer sort of comes from the Navicular Syndrome horse and the chronic clubbed footed horse, just look to the hair line. I had always had great success with Navicular horses by looking to the hair line for guidance as to where the shape was wrong and what needed to be changed to make the horse more comfortable.
In recent weeks of late 2008 I have met a horseshoer that is into researching everything out there and he is having a great time learning the stuff I have found over the years. He presenting to me an article by Lyle Bergeleen about the hair line and how to read it, it was amazing to find that some 15 years ago someone had almost hit on the way to judge what was wrong with a hoof and how to fix it. The differences between Lyle's article and the functions of the hoof are fairly small, so the man was definately on the right track but there is so little mentioned of his ideas in this modern age of hoof care.
If a wild horse has a straight hair line and a domestic horse is forced into a distorted hair line then we have to consider who changed the hair line and how, then plan on changing it back.
The question of why a horse that is Navicular Syndrome, Club Footed or badly foundered has a curved hair line is hard to answer directly as many things may have caused the change to start with but it is the continuation of the problem that cripples the horse.
The endurance horse that had one good frog and one atrophied frog was only at the beginning of the changes that lead to Navicular Syndrome, the low level pain was there evidenced by the poor weighting of the frog. Pete Ramey writes about frog stimulating pads to help with navicular horses which is good but does not address the true problem. You are bypassing the cause of the problem by putting a pad in close to the frog which will help develop the digital cushion and stimulate frog development but will not address the root problem.
The cause of the pain is linked to the high coronet band in the quarters, luckily the endurance horse only had a few mm of height change in the coronet band. So simply scooping the wall, sole and bars to reverse the coronet band shift has allowed the endurance horse to develop a proper frog within 1-2 weeks. The horse now lands heel first with confidence on that foot.
Why scoop the sole at the quarters, this is a tricky one, as the horse is not able to move the foot through a proper range of motion there can be dead sole trapped in the quarters region changing the thickness of the sole and making it painful for the horse to load the palmar wings on the pedal bone. It is subtle and requires a good eye to identify and remove this waste sole. The weirder cases are the horses that stumble a lot, you may find the waste sole only on one side and the horse stumbles trying to avoid to built up junk.
The reason for the pain in the back area of the hoof is linked to the connective tissue that supports the laminae and the back of the hoof at the palmar wings, this palmar sling is responsible for part of the weight bearing process and most used when cornering. Now remember a lot of this occurs well before the horse becomes toe first in landing. Just like the club footed horse the stride is still heel first but short and uncomfortable. The horse is quite reliant on the leg that is comfortable. This motion unfortunately does a large amount of damage to the upper body. So use that hair line to judge how much scooping is needed, and be aware that if the hoof is long term affected from club foot or founder you may have to scoop the frog in a similar curve to the walls or bars as you do not want to create a pressure point by loading the area of the frog directly under the navicular bursa.
If you don't trim the frog down after trimming the quarters the horse may be unable to stand.
This all means that Navicular Syndrome starts long before any boney changes occur at the pedal bone or navicular bone as is the reason why horses are diagnosed with NS without visible damage to the navicular bone and if left untreated the changes to the bone occur to confirm the vets suspicions. Now if a routine of trimming the damage out of the hoof occurred when the first signs of pain became obvious the further damage to the bone can be stopped.
Prof. Robert Bowker has stated to easiest way to fix NS horses is to keep the toe short. It takes around 18 months for the horse to recover this way, my usual aim is to have a NS horse sounder and striding out in 8 weeks, yes 8 weeks. I am currently working on a horse that has NS bad enough that the Vets next solution was a Palmar Digital Nueroectomy where they cut the nerves so the horse can't feel the pain. In 6 weeks we have him cantering for the first time in years and this horse is only 8 years old.
The hoof has only 3 true points of loading and they must be loaded equally and supported equally to achieve a strong functional foot. These three points are the central section of the dorsal hoof wall and the two quarters. All of the rest of the hoof is either working in concert with these parts or against it. The hair line will guide you to the points that are working against the support of the hoof. Bergy was very close to the mark when he identified a way of finding the errors in the hoof capsule he was just not up on the ideas that make barefoot work.
In club feet the forces created by the loading of the lateral cartilages and palmar wings can be enough to create a rotational energy that pulls the pedal bone away from the hoof wall creating a dorsal dish. We know that the DDFT does not create enough force to rotate the pedal bone and the lower the heels the less the energy in the DDFT is transfered to the pedal bone. Pushed up quarters in foundered horses and NS horses can also created the same dorsal dish. The heavier the horse the more energy transfered through the palmar wings, a curve to the coronet of a warm blood will do twice the damage inside the hoof capsule of a light weight hack with the same curve.
I have seen warmbloods with complete disconnection of the dorsal wall as if foundered just from the energy transfered incorrectly from the palmar wings, the horse went through 2 years of farriers trying every thing to fix the problems without seeing the slight change in the coronet at the quarters. This horse was so sore that going barefoot was not an option as he would have to wear boots 24/7 which just canít be done. I ended up shoeing the horse in Plastic Marathons horse shoes, these things are just brilliant for the badly damaged horse as it allows you to prepare the hoof to go bare with out the dramas of boots and discomfort when the boots are not on. Every bit of pain a horse feels in its feet creates inflammation and this inflammation will affect blood flow.
Working from my equine massage training and dealing with other professionals in the massage world, we can identify a horse that has the beginnings of NS or a clubfoot or longterm founder by looking at the trapezius cerviacus and the triceps as both areas changes as the horse moves to toe loading. The first step before toe first landing, the horse can land heel first but weights the toe in preference to the discomfort of loading the damage quarters.
This tensing is in part why the dorsal dish can occur but the effect is both energy and muscular based so each horse will have different problems.
With foundered horses knowledge of this load changing due to positional shifting of the hoof wall means that a foundered horse can be made sound within 2 weeks of the onset of damage. A sinker is more uncomfortable from the pressure on the lateral cartilages and palmar wings than from the original laminitis. Pete Ramey used to talk about a heel bevel which is a little hard to understand but the principal is to use the good part of the hoof ie: the soft tissue part of the hoof with less laminae tearing to support the front of the hoof. This may lead to NS changes within weeks and any horse that had coronet changes prior to founder is in dire need of the scoop being carved in, this is the opposite to the heel bevel but is more in concert with what the hoof needs at that time. Having worked on horses treated without the correct adjustments, I can say the difference between boots and pads causing the horse to swap feet every 2 seconds, to hard ground surfaces causing the horse to swap feet every 5 seconds to scooping the quarters on a NS and badly foundered horse and allowing 30 seconds between swapping feet. That is a fifteen times improvement over boots with pads and a 6 times improvement over a barefoot trim with a heel bevel. The horse cantered for the first time in 10 years 8 weeks in to the trimming meaning that both the NS problems and long term founder problems were correcting physically if not yet cosmetically.
If you want to find the location of the navicular bone within a hoof capsule of the average horse, it is midway around the coronet band between heel and toe, at 10mm below the coronet band, this means as the coronet band rises at the quarters the navicular bone and the back of the pedal bone rise out the standard sole plane.