Common Pathologies of the Equine Hoof

Flares & Wall Separation, Heels, Frog/Thrush, Flat Sole, Laminitis & Founder, Navicular

Flares & Wall Separation

Wall flare is excessive hoof wall that grows outward due to excessive length and insufficient wear. The wall is strongest when the entire hoof wall from the coronary band to the ground is straight. When it's not, the wall is literally separating away from the coffin bone. It may look like bell bottom pants at the bottom outer edge of the hoof. Or it may not be so obvious. You can feel flare with your hand. Begin with your fingertips at the top of the hoof wall and run them down the hoof wall towards the ground. You can usually tell how the "hoof wants to grow" by looking at the upper 1/2" or so of the hoof growth just below the coronary band. Sometimes though, so much of the wall is flared and so close to the coronary band that it is hard to see. Flare is due to laminitis or long-term mechanical stress. When wall is overgrown, ground contact will mechanically begin to pry the wall away from the bone. In hind feet that are overgrown in the toe, yet the heel is too short, a bulge ("bull nose") will form halfway up the toe wall. The white line at the bulge is stretched because the unusual mechanical forces in this shape of hoof pull the wall away from the bone.

Flare and "white line separation" are basically the same thing. When looking at the sole of a flared foot, the white line is dirty and stretched or may make a small groove between the wall and the sole. Flare to the hoof is like pulling two pieces of velcro apart. But unlike Velcro, it cannot be put back together. Well connected wall must be grown down from the coronary band.

In true white line disease, fungus and/or bacteria become established in the stretched white line and travel far up under the hoof wall, destroying tissue, and sounds hollow when you tap it with a tool. This requires aggressive treatment with a product like White Lightening.

These hooves have been soaked several times since Oct 5th, 2007. I'm anxious to see the improvement at the next trimming. Stay tuned.

Flares are painful to the animal. Think of having your fingernail slowly ripped off! Laminitis (inflammation of the white line) is so painful that the horse will stand in the "founder stance". Even without founder, a flare can be painful enough to make the animal noticeably unsound.

Building adequate sole is more than just leaving it alone. Remember – it’s all skin, even the hoof. If the horse is lacking in nutrition or ill in some way, the organs are preserved while “skin” is left on its own.

Typically horses will stay thin soled until you’ve grown in a totally well connected wall. So get rid of that flare!

For more information and lots of good pics, please see: http://www.barefoothorse.com/barefoot_Flares.html

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Heel Pathologies

Contracted Heels/Hoof - The hoof capsule deformity presses in on the sides of the back of the hoof, squeezing the soft tissues of the the back of the hoof making the heels narrower. "Contraction robs the horse of its natural blood pumping, shock absorbing expansion almost as bad as a nailed on shoe....The very best thing to do for contraction is not to worry about it. The hoof "knows" what its optimum shape is and is constantly trying to go there. All we really have to do is remove the excessive hoof that is working against the horse and allow plenty of movement on bare feet......if the horse is sound on his bare feet you are doing an exceptional job with his hoof care, so find something else to worry about." - from Pete Ramey's Making Natural Hoof Care Work For You - 2003

Under-run heels/under-slung heels - refers to the position of the heel buttresses being too long and too far forward under the hoof, toward the toe wall. They generally arise because the heels have not been sufficiently shortened. For under-run heels resulting from excessive growth in the absence of insufficient natural wear, correction is simple; apply the natural trim. It may take several trims depending upon the severity. The last thing we want to do is "force" the hoof to conform.

Thrush

Thrush can be rather painful for the horse causing it to land toe-first to avoid the heel pain. Thrush typically has a nasty rotten smell, the tissue is black and slimy, and it tends to begin along the collateral grooves. Though an infection does not have to be this obvious. When an animal has deep central sulcus thrush it will be evident by the crevice you see between the heel bulbs and into the center of the frog. This crevice should not be there. It is the result of the bacterial/fungal infection.

Equine thrush is caused by anaerobic bacteria (living without oxygen) that, when trapped in moisture, can create an infection that slowly eats away at the horse's hoof tissue, particularly the frog area. Most of the time this will create some mild discomfort, but as long as it is addressed quickly it rarely does anything more. Left unattended for a period of time, the thrush can eventually make its way into the sensitive areas of the frog invading the digital cushion deep inside. The picture to the left above is of a mules right fore hoof. The heels are WAY too long, as are the toes, the frog has thrush that has invaded deep into the hoof structure. The picture to the right is the left fore hoof of a horse showing central sulcus thrush evidenced by the deep crevice between the heel bulbs, and also along one of the collateral grooves.

Equine Thrush has always been thought to be associated with unhealthy living conditions, but this may not be totally accurate. Thrush is also not a wet environment problem only. Many years of studying hooves and investigating successful treatments of thrush have brought to light another picture of the cause of this disease. Poor hoof care can only partly be identified as a cause (for example, with horses kept standing most of the time, unable to move freely). Properly trimmed and maintained hooves & frogs, cleaned on a fairly regular basis and unrestricted movement contribute greatly to ridding the problem of thrush.

Fungus is usually primary with a secondary bacterial infection eating tissue. Whatever you use, don’t use something that kills live tissue. While Kopertox is traditionally used to treat thrush, it is a nasty poison, both for us and the horses, and the environment. It also kills live tissue, providing more "food" for the invading organisms. I personally have had very good results with a product called White Lightening from Grand Circuit. These products should be used when the thrush is invasive and wide spread. Lysol Concentrate – All Purpose, any color, can also be used. Mix according to directions at 2 oz per gallon. Do not make it any stronger. Do 30 minute soaks three times per week. EasyCare Soaker boots work very nicely for soaking.

For deep central sulcus thrush ( that crevice I talked about above), use what I call "Ramey Goo". This is a 50/50 combination of Triple Antibiotic Ointment and 1% Clotrimazole Athletes Foot Cream that Pete Ramey came up with and has had much success with. (Generic Brand is fine) I buy 1 oz tubes of each, mix them together in a small container and then use a small spatula to put some in a 60cc catheter tip syringe. The easiest way to get the goop out of the tubes is to cut off the bottom of the tube and squeeze it out rather than trying to squeeze it out the tip of the tube. When you use two 1 oz tubes, you end up with 2 oz's of cream. Only put 1/2 to 1 oz of the cream in the syringe at a time or you won't be able to hold the syringe in one hand and plunge the "goo" into the crevice.

Do not tolerate deep crevices in the sulcus! This is not normal. It’s not so much about the “stuff” we treat it with as is the stimulation required for healing. Every pressure and release action stimulates growth. Foam rubber (like using boots with pads and exercising the horse) and 4” deep pea gravel work wonders. If you beat thrush in the sulcus, you’ll beat it everywhere else.

Please see Pete Ramey's article on Frog care for further information.

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Club Feet

With the Club Foot, one foot is steeper than the other. It wants to, needs to, etc. but it is not a hoof problem. The horse is adapting to something else. Go on a detective mission. There is/was an injury, nerve damage, or opposite hind stifle problem as examples. Massage folks can really help the club foot horse. Please see Pete Ramey's article on the Club Foot.

Flat Sole

Is there truly a flat footed horse or is he just living on very hard terrain? Horses on hard flat terrain won’t like deep concave hoof because they are peripherally loaded. We must always consider the animals living conditions and terrain to determine the best hoof for the horse. Hard packed ground – flatter looking foot – concavity fills in. Soft ground – more concavity. Can have a winter foot and summer foot. Summer – hard ground – sole fills in. Winter – exfoliate. Frozen terrain, hard ground, flatter sole. You'll need boots for traction on flat footed horses until concavity can be built. Yes, concavity can be built with the natural trim over time coupled with the proper environment.

Laminitis & Founder

The word "laminitis" means simply the inflammatin of the laminae. The "laminae" is like the "velcro" between the coffin bone and the hoof wall. By the time you see signs of lameness, the damage is already taking place. The trigger is the hindgut bacteria streptococcus bovis. The horses natural diet of mixed grasses provides structural carbohydrates, but fructans (non-structural carbohydrate) usually dominate the engineered grasses and hays we feed our horses today. The horse (or any other mammal) has no enzymes to digest the non-structural carbohydrate; fructan. They are present in great quantities in our sweet feed, rich cultivated pastures and our beautiful "horse quality" hay. Fructan, sugars and starches pass undigested into the hindgut where they undergo rapid fermentation to lactic acid (which can then be utilized by the horse, but not quite naturally). S. Bovis is the bacteria primarily responsible for this and can undergo a 1680 fold increase in numbers during a carbohydrate overload that leads to laminitis.

Dr. Christopher Pollit has also proven that the laminae readily separate when they are starved of glucose. A major feature of any metabolic stress is a reduction of glucose supply to the extremities. This is done to preserve the more vital organs. When the digestive bacteria in the hiindgut go through the massive die-off often associated with sudden changes in diet and with the development of laminitis, the resulting lack of digestive bacteria creates an immediate "starvation" within the horse. The forces required to cause physical separation are much greater in the hoof walls (when they are in a solitary support role without aid from a well callused sole).

This is one of the reasons we see so much more resistance to founder in hooves that are maintained in a natural form. The shear forces are greatly reduced.

Naturally shaped and developed hooves have much more thorough blood circulation in place. Dr. Robert Bowker - Theory of Hemodynamics. The blood pumping action of the foot is much more advanced and difficult to obtain than most farrier realize. It goes far beyond simple frog pressure and requires proper development and flexion of the foot from the moment of birth. It is not only important for energy dissipation and for easing the burden on the heart, proper hoof function and circulation also gives the foot profound advantages and resistance when laminitis does make it to the acute stage and circulation loss becomes a more important factor. The foot must be allowed to flex and function at this stage to aid in circulation.

The same thing that causes fat causes laminitis; excess or improper feeding. Not all horses have to be fat to suffer from laminitis. If owners would recognize that increasing fat on a horse is reason for panic, laminitis would become a distant memory. Underweight horses have also been foundered by caring owners pouring feed and grains to their horses in an attempt to put weight on them. The owners are just keeping the horse in constant metabolic distress and foundering feet. The horse has no means to utilize the rich (high non-structural carbohydrates) feed. All the horse needs to gain weight and grow healthy hooves is a simple free-choice, mixed grass hay diet (plus salt and minerals).

While it is illegal for farriers/trimmers to diagnose laminitis, we must deal with its consequences to some degree on almost every domestic hoof we see. Too rich of a diet weakens the attachment of the hoof to horse.

Ripples or red stripes on the hoof walls, abscessing, fan shaped growth rings, obesity, abnormal weight loss, dull, shaggy coats or an unwillingness to shed winter coats, flat soles, wall flares or while line separation, negative attitude, laziness, and hoof sensitivity should be cause for immediate concern for anyone associated with horses.

Founder is when the laminitic condition continues until the hoof wall loses all attachment to the coffin bone and rotation begins to occur.

Laminitis and Founder protocol – Trim, boot, pad. We must remove the mechanical force to walls. Boots with pads provide great relief to the laminitic or foundered animal. Look at boots like bandaging. If you horse injured his leg and required daily bandaging you most likely would hesitate. We must look at booting the laminitic and foundered horse the same way and provide protection to the hoof by using boots and pads following a natural trim relieving the walls and the pain of the wall being pulled away from the bone.

For more detailed in depth information on this subject please refer to Pete Ramey's article on laminitis. The above information is based upon this very in depth article.

Navicular

Genetically, the horse thinks they are a wild horse. Parts of the hoof need the right amount of pressure to develop structure. This is why it is so important that foals get to move about and play and not be contained in a stall or small area. Without contact with the earth and movement, their hooves will not develop properly.

Our equine friends need a lot of movement on uneven terrain and side to side flexion to develop the needed structure.

The "Theory of Hemodynamics" (the flow of blood).
Upon loading of the heel, the capsule expands, sucking approximately 1/4 of a cup of blood into the foot.The weight descends onto the sole. The hoof sucks blood into the hoof as impact is beginning.

At peak impact there is a moment in time that the blood can't move. It gets pinched off and pressure builds. At breakover, the horse takes the weight off the sole and all the pressure is released back up the leg. This is a very important part of how movement is helping to circulate the blood. If you don't have a heel first impact and sole pressure, this function is greatly diminished.

During a study in which only the outer wall is weight bearing versus taking that same foot and putting it on foam or pea gravel, it was found that the capillary fill is much greater when there is sole and frog pressure than when a horse is hanging from its hoof walls. And this is merely standing still.

The hoof wall is a big spring that is designed to pull the hoof back together. The force of the horses weight causes hoof expansion, but only one thing causes the hoof to snap back making it ready for the next impact, the hoof wall.

To develop lateral cartilages and internal structure, use pea gravel in the turn out areas, ride in boots and pads, trim to encourage a heel first landing.

Navicular Syndrome/Disease

The navicular bone acts as a pulley for the deep flexor tendon. It is classically thought that the navicular bone would go through changes & develop lesions, spurs that would cause pain to the back of the foot and it was thought to be incurable. Navicular Syndrome simply means that the horse hurts in the back of the foot but the cause is unknown. Navicular Disease is when there are actual changes in the bone that shows up on x-rays.

Traditional methods would typically use bar shoes and then pads, just bandaiding the problem, continually raising the heel driving the coffin bone tip down into the sole.

James R. Rooney DVM

Toe first landings have been proven to lead to navicular syndrome and navicular disease. James R. Rooney DVM (The Lame Horse, among many other books) spent a career studying the whole horse and performing thousands of dissections. During his studies, he found that the damage was happening to the deep flexor tendon first, not to the bone. In no cases was there damage to the bone and not the tendon. He found yellowing of the cartilage that surrounds the navicular bone and he could recreate this yellowing with heat from a light bulb. The only thing that could cause this on its own was higher friction. What causes higher friction in this area? Excessive force. Unnatural force. Dr. Rooney built a machine to put the limb of the cadaver in a constant toe first landing position and was able to duplicate this observation he'd seen in his dissections. He then built other models and examined the various forces to the leg, which further confirmed his theory that chronic toe first landings lead to navicular. Horses should only land toe first as they move up hill or on rocky terrain. Even after Dr. Rooney published his findings in 1974, tradition won out over science.

Robert M. Bowker, VMD, PhD - Michigan State University Equine Foot Laboratory

Dr. Bowker furthered this navicular research. General loss of mass in the coffin bone, when it reaches 30-40%, will begin to spread to the navicular bone and affect it. This is blamed on peripheral loading, forcing the horse to bear all of its weight on the hoof wall and taking away the pressure on the frog, sole and bars.

NASA has proven that when astronauts are in space too long and have a lack of pressure to their bones, the bone starts to take away density. This is why weight bearing exercise helps us build strong bones. The exact same thing happens to equines when they don't get enough sole pressure. It registers to the horse as a lack of necessary force and the body starts to remodel the bone. Excessive pressure removes bone as a whole, at the distal border of the coffin bone. Inadequate pressure can remove bone density. The horse needs the right amount of pressure that is provided by natural movement, heel first landings, sole, frog and bar pressure.

Washington State University studies using MRI technology, found damage to the soft tissue that we never knew existed, shows up long before x-rays show changes to the navicular bone. This is just one more study that comes right back to the toe first landing compensating for back of the foot pain, that leads to navicular syndrome/disease.

What can be done for the navicular horse or mule?

• Develop the back of the foot
• Increase exercise
• Bring in pea gravel
• Trim for heel first landing
• Use pads and boots to develop the frog/digital cushion
• Treat the hoof for bacterial and fungal infections

A horse can have lots of damage to the navicular bone and not be the source of the pain. Damage to the bone is the result of the pain in the back of the foot causing the horse to walk toe first. While you can't fix changes to the bone, it doesn't necessarily cause pain to the horse either.

Rehabilitation has less to do with the changes in the navicular bone and more to do with how poorly developed the back of the foot is, and how much you can get the horse owner to take steps to develop the back of the foot. It doesn't have to be a death sentence. Treat the horse or mule with a natural trim. If there is still pain, boot and pad the horse. While some horses will remain pasture sound, needing to be ridden in boots and pads, others can recover and be sound riding barefoot animals.

Call for a consultation appointment & first trim today.

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