What is Navicular Disease? Navicular ‘disease’ is the degeneration of the navicular bone. The navicular bone acts as a fulcrum to the pulley effect of the deep digital flexor tendon. The navicular bone is a sponginess bone that is capable of remodeling based on the tension placed on it by the tendon. True navicular disease shows up on x-rays as key hole shaped areas of bone that has remodeled. Navicular Syndrome is a non-specified heel pain. Both are manageable, and in some cases curable!
Why traditional treatments don’t work
Here are a few treatments your vet or farrier may recommend.
Above are a few examples of typical Navicular hooves
Picture one: A contracted heel, (oval shaped hoof) and no frog. Part of the pain navicular horses exhibit is that the hoof has very poor collateral cartilages (the back 1/3 of the hoof is cartilage and it will atrophy if unable to expand and contract properly either due to poor frog or years in a metal shoe). This hoof is also very small for the size 15 hand mare, wearing the shoe size of a medium to small pony!
Picture two: Here is another typical trait of a navicular horse- the long toe/low heel syndrome. The length of this toe is putting so much strain on the tendon that it is causing pain and undue strain directly onto the navicular bone. The low, underrun heel shows us that this hoof has poor rear cartilages and is not giving proper cushion and protection to this hoof.
Picture three: An upright long underrun heel, and long toe. This poor horse has the triple threat combination.
The good news? All of these hooves are fixable! The first hoof needs to be hand walked in therapeutic pads and some deep penetrating hoof cleanser such as CleanTrax. Hoof number two was sound after one trim, and hoof number three is what our navicular case study is about.
In December 2012 Berry was diagnosed with Navicular Disease in both front feet. She had been suffering for 6 months with front end lameness, and ‘pointing’ (placing one foot in front of the other, in order to minimize weight bearing on the affected hoof). Berry’s owner went through 3 Farriers in 12 months, but Berry was getting significantly worse.
These radiographs show severe degeneration of the navicular bone as well as several key hole or lollipop lesions. These lesions are what causes pain to the affected hooves, now that the navicular bone is no longer smooth, the deep digital flexor tendon is sliding on a rough surface and causing pain.
Traditional shoes did nothing for Berry, and her pain, graded on a scale of 1-5 was at a 3 for her left front and 2 on the right. Her heel shows severe lack of caudal (rear support to the hoof).
Here is your typical long toe low heeled hoof. This shoe job is only 6 weeks old. The middle picture shows the poor fog quality, skinny and infected. Picture three shows the long toe, and how the hoof is flaring upward. The white pigment at the toe, just above the shoe shows that the hoof was so long that the toe was dragging, wearing the the toe.
Here are Berry’s after: The heel has been significantly lowered and the angle is now congruent with the first ½ inch of the hoof from the coronary band down. The heels have been brought back, trimmed down to a credit card’s height above where the healthy frog should be. Take note that this frog is NOT healthy so I trimmed the heels relative to where a healthy frog would be. The heels are still contracted- notice how close together they are. Finally the toe has been shortened to provide better break over. Finally, I applied Thrush Pack this will kill the thrush and provide a gel cushion. I used an Equisock over the hoof to hold in the gel as well as give support. After our trim, Berry was walking with a smoother stride.The most important thing to remember in treating any hoof with pathological conditions is to NEVER try to make it ‘normal’ . Our job as owners and hoof care professionals is to make sure we take our time. The comfort of the horse is paramount. The hoof is a dynamic structure, constantly changing, and it will return to healthy function.
Second Visit 4 weeks later
Here Berry is right after I removed her Equisocks. The socks, as usual, have caused a tremendous amount of growth, as evidenced by her long heel in picture one. You can see in picture 2 how wide her heels have spread already. Thanks to the hoof packing, it fit in the sulcus on either side of the frog, thus stimulating the rear cartilages and helping the whole foot spread. This would not happen in a traditional metal shoe of any kind. The shoe does not allow the frog to touch the ground, therefore loosing it’s ability to stimulate the cartilages. The metal shoe would also prohibit the hoof from expanding and contracting, causing the cartilages to atrophy allowing the whole hoof to grow forward. Picture 4 shows the extreme amount of hoof wall grown in 4 weeks. The last picture is of the used Equisock- notice how the packing has filled in around the frog.
Right Hoof After
This is the long toe low heeled hoof after the trim. A healthy heel should be at the widest part of the frog, this heel is still forward of the frog. The frog is still of poor quality, but we have successfully treated this hoof for thrush, and now we are going to add an Equisock with Equipack CS and Thrushpack gel. You cannot cut this heel back to make it ‘correct’ without making Berry first.
2 Different Sizes
The hoof on the right is smaller than the hoof on the left. The right hoof is the hoof with the higher level of pain, and therefore the hoof that bears the least amount of weight. Pressure is the stimulus for growth, so the left hoof is loaded more, making for the hoof grow. Since this is hoof is taking more weight, it is growing improperly. Once Berry is more comfortable, both feet will be equally loaded.
This frog is in the process of healing. It is developing more mass, and no longer is infected with thrush.
Long Toe- Still. . .
Even though this toe is still too long, and the heels are low, Berry is sound for the first time in a year.
Any changes in a hoof need to happen gradually so as not to cause more pain or invade sensitive structures. So even though this hoof is not pretty, the horse is comfortable and that all that matters. The hoof will return to health with time and patience!
Thrush Pack Step 1
Here the thrush pack has been applied on a clean, freshly trimmed hoof. The purpose of the thrush pack gel (a part gel that mixes and sets, making an insert similar to one you would find in your own tennis shoe) the purpose of this gel it to replace not only the poor frog quality, but to settle into the sulcus alongside the hoof, stimulating the cartilages and spreading this contracted heel.
No more flares:
Here is a the toe, it has been shortened and brought back. The flares have been removed, removing unnecessary stress on the outer wall.
Here is step 2 of the thrush pack. After the gel is poured in, I put plastic (provided with the thrush pack) over the gel, pressing it into place. I let the gel set up for a few minutes, and after the gel has set you carefully peel the plastic away. If the gel tries to lift away with the plastic, no worries, just push it back down with your finger while continuing to lift- the Equisock will hold your gel in place.
Here is the rear view of the gel. It is not necessary, but will not harm the hoof. You can leave it on and wrap the Equisock right over it.
Typical ‘navicular hoof with wedge egg bar shoe.
This wedge egg bar shoe is designed with a wedge to lift the rear portion of the hoof and take some of the stress off the navicular bone by reducing tension on the deep digital flexor tendon. The wedge built into this shoe completely prohibits the hoof from expanding and contracting, exacerbating the underrun heel.
This ‘natural balance’ square toed shoe is designed to speed brakeover it is thought to reduce the tension on the flexor tendon. The rocking action of this shoe puts more strain on the navicular bone as well as increasing the risk of hyper-keratinized horn tumors in the hoof wall.
Before and After
The Finished Product
This is the Equisock wrapped over the thrush pack. Berry not only gets the stimulation of the gel against the sulcus alongside the frog, but the gel gives her added cushion.
Stay Tuned for more updates on Berry!
Remember These Hooves?
Dramatic Before and After’s
Hoof #1 has chronic thrush, a contracted heel, flat soles and terrible wall quality. Here we can see the heel has expanded, the hoof wall has become more round thanks to hand walking in Hoof Rx Therapeutic pads. The thrush is
Gone thanks to Clean Trax hoof soak and Hoof Rx spray. This mare is now sound, and her hoof has gone up a shoe size too!
Above: Long to, low heel
Right: the dark peeling area is exfoliating sole.
There is no doubt here this hoof is neglected, but would you believe this one is the easiest hoof to fix- the reason? There is a lot of hoof to work with, so I can do some drastic trimming without ever invading sensitive tissues.
You can see the progression of this flaking false sole. (False sole is sole that is no longer receiving nourishment from the hoof.) You can identify false sole by it’s flaking and peeling texture. I never ever remove live sole in order to create concavity, but as in this hoof, I was easily able to remove this flaky powdery mess. Below is a hoof that was trimmed using the “Strasser” method. This hoof was trimmed invading the live sloe, cutting the hoof making concavity. You may notice this hoof is no longer attached to a horse. . . This is a cadaver off a foundered horse and a farrier’s attempt to ‘fix’ this hoof and make it ‘normal’ right away. You can see how different the hoof above looks, I never invaded the live sole. Notice the marks around the edge of the hoof where the knife was digging into the sole.
Strasser Trimmed Cadaver Hoof
Live sole has been invaded
This once awful hoof is an example of a trim that was ‘fixable’ in one session. The hoof was so long, that I was able to remove the excessive material without ever invading sensitive tissues, live sole or laming the horse. The photo at right shows how there is nice, consistent width all the way around the hoof wall.