Become an Informed Hoof Care Consumer

Become an Informed Hoof Care Consumer Monique Craig The Epona Institute

The one important factor in becoming an informed hoof care consumer is the capacity to recognize a healthy hoof from an unhealthy one. Another important factor is the trimming method: an informed consumer needs to be able to assess whether or not the trimming helps to maintain the hoof at its optimal health and function. Choices in prosthetics (a.k.a. shoes and boots) can only do so much if the hoof is not properly trimmed. Finally, the consumer needs to be able to assess whether his or her horse is a candidate for prosthetics and which type would be the best choice given the situation.

What are the criteria for recognizing a good hoof? I generally follow a protocol for assessing the quality of hooves. I start by looking at the external stance of each hoof and leg. Then I check the shape of each hoof. I check the stance and quality of the hoof before and after trimming since most hooves will be somewhat misshaped at the end of a trimming cycle. Ideally, hoof deformities should be eliminated after each trimming. I also would recommend taking preventative radiographs at least once a year.

Hoof Stance The hoof must stand under the bony column. The hoof needs to support the load over each limb. For instance, if the hoof is too far forward it will not only cause undue stress to the tendons and ligaments but also deform the hoof capsule over time.

Figure 1: The hoof in fig. 1A is not standing under the bony column (green lines) – it is too far forward. The hoof in fig. 1B is standing adequately under the bony column.

Capsular deformities affect proper hoof function and “internal bone stance”. By “internal bone stance” I mean the alignment of the bones within the hoof capsule and lower leg which must be judged from a radiograph. Eventually, these changes may affect not only the entire conformation of the horse but also the horse’s locomotion. This chain of events may even create lameness issues other than in the hoof. This also raises an interesting question on defining true limb and hoof conformation. Often, people mistake capsular deformities and its effects for being the normal conformation of a particular horse. Some horses indeed have bad hooves but with the choice of proper trimming and prosthetics, it is generally possible to lessen some of these problems.

Figure 2: The hind hoof in fig. 2A was taken prior to trimming.

The same hoof hind in fig. 2B was taken six months later after trimming. The hoof stance is not adequate in fig. 2A compared to that of fig. 2B. The shoe is not helping the stance of the hoof in fig.

2A. The stance is vastly improved in fig. 2B even without a shoe.

This difference and improvement in the hoof is due to the trimming method and the choice of adequate prosthetics for this particular horse.

A hoof stance that is under the bony column does not necessarily mean that the hoof is devoid of deformities. As mentioned previously, it is very important to check the “internal stance� of each hoof of the horse (see figure 3).

Figure 3: Both radiographs show the hoof under the bony column.

However there is a vast difference in internal stance between the hoof in fig. 3A and that of fig. 3B. In figure 3A, the pedal bone has shifted forwards within the hoof capsule. The arch definition (red curve) is collapsed as a result of this shift. In figure 3B, the pedal bone is standing under the bony column. The arch definition is well-defined.

Shape of the Hoof Capsule We are all familiar with the “pads” visible on the underside of a cat’s or a dog’s paw. Ancient ancestors of the horse also had such pads. It may be hard to conceptualize that the horse is still a padded animal. The horse evolved from a four-toed animal (Hyracotherium.) This animal had a large central pad. As the earlier horse changed from a four toed to a single toed animal, the central pad receded backwards and became encapsulated by the hard hoof capsule. When you pick up your horse’s hoof and look at its sole, you will notice the frog. The frog is partly overlaying a

left over (i.e. vestigial) larger pad. This pad is referred to as the digital cushion (see figure 4B.)

Figure 4: Figure 4A shows the solar view of a live hoof. Figure 4B shows at top view of the digital cushion and the pedal bone (navicular bone not shown) as seen inside the hoof capsule. Figure 4C depicts the internal view of the keratinized sole without the digital cushion. Figure 4B and 4C are that of cadaver legs.

This pad still plays a role in supporting the load placed upon the limb. In an ideal situation, a large percentage of the load should be placed over the frog area (see radiograph in figure 3B.) The load is defined by the force placed by a limb upon the entire hoof.

Among “hoof gurus” there are different proposed notions of what is “ideal” for this support. Many will mention that the frog area should make up two thirds of the hoof capsule. I feel that it is not an unreasonable ideal, but in reality the frog tends not to be a reliable external landmark (see figure 5.)

Figure 5: The solar view of the hoof in fig. 5A shows a large frog to toe ratio. The toe length seems too short according to some standards. However, the radiograph of the same hoof shows an adequate toe length for this horse.

Good hooves have different shapes – there is not a single, easily stated ideal shape. The hooves displayed in figures, 4A, 5A and 6B have a good quality frog with a good toe to frog ratio but they appear quite different from the outside.

Now that you have some notion of the frog to toe ratio you will need to be able to recognize whether the frog is of good quality and whether the entire capsule is of adequate shape to allow the hoof to function correctly. The frog shape should be wide and well defined. You need to be able to see the frog sulcus in the middle of the frog. The frog sulcus is a dip in the middle of the frog (see figure 6B.) A lack of sulcus definition and the walls being pulled in often means the heels and bulbs are contracted (figure 6A.) Compare figures 4A and 5A with that of figure 6A.

Figure 6: The solar view in fig. 6A shows contracted heels, bulbs and poor frog definition. The same hoof (many months later) is shown in fig. 6B. This is in not perfect but its entire conformation has improved. The frog is wider and has a well defined frog sulcus.

The heels and bulbs are not contracted. The entire sole is wider and longer, thus providing adequate support for the limb.

Heel to Bulb Distance You also need to check the heel to bulb distance. This distance can be checked in two different ways. One is by looking at the solar view of the hoof as in figure 2 -- look at the red dots at the heels compared to the bulbs. The other way is to look at a lateral view of the hoof as in figure 7. The reason for looking at this is to address the amount of support that the sole provides for the limb.

The hoof is in figure 7A is standing under the bony column but the support provided by sole is inadequate. Ideally, the entire sole (called “foot length� in figure 7) should be placed under the bony column. The hoof needs plenty of sole length for support.

Figure 7: The lateral view in fig 7A shows a hoof that has a large heel to bulb distance and inadequate foot length. The same hoof (several months later) is shown in fig. 7B. You will notice that the foot length has improved as the heel to bulb distance decreased.

The hoof in fig. 7C shows a good hoof. There is plenty of support for the hoof and a small heel to bulb distance.

Increasing the foot length does not mean an increase in toe length.

Figures 3B, 4A and 7C belong to the same horse. You will notice that the horse has a short toe and yet adequate sole length. The hoof in figure 7A is badly deformed as a result of reducing the toe without increasing the foot length. In other words, reducing the toe to obtain a better frog to toe ratio is not enough to maintain a hoof in good shape.

Checking the Trim Once you understand what to look for in the hoof, it will become simpler to assess a good trim. A good trim should help maintain the hoof under the bony column, provide adequate surface area at the sole to support the limb. The sole depth should be at least half an inch or more, especially if the horse is left barefoot. The frog needs to have a visible sulcus and be wide. A large portion of the hoof should be behind the tip of the frog. The frog should either be very slightly higher than or even with the walls so that it is touching the ground. If you have any doubt about the trim, have radiographs taken to check the internal stance, arch definition (figure 2), toe length and sole depth. An ounce of prevention is worth a pound of cure!

Choices in Prosthetics - when Trimming Alone is Not Enough Sometimes despite good trimming methods, it is impossible to maintain a hoof within the parameters mentioned above. Some

horses wear their hooves too fast while others have loading problems that can not be resolved solely by trimming.

Metal shoes: Metal shoes have been used for centuries. They were initially used to prevent hooves from over-wearing. A typical metal shoe is set at the periphery of the hoof to offer protection.

Metal shoes do not allow the hoof capsule to flex in all dimensions since metal is miles away from matching the mechanical properties of the hoof keratin. Whenever possible, metal shoes should be removed once a year for a couple of months to allow the hoof capsule to restore. I would also advise limiting the amount of metal placed at the hoof. These days there is no reason to put serious hardware under the hoof since plastic pads and packing material provide an alternate choice to the more aggressive form of metal shoes. If used alone, metal shoes are cost effective and help doing damage control against over-wearing of the hoof. Metal shoes are not necessarily evil when used wisely.

Plastic boots: Plastic boots are a good alternative to metal shoes.

Boots are usually used while the horse is being ridden to provide protection to the hoof. Boots are removed after riding. They work well for horses that do not have hoof issues and that can be maintained barefoot.

Composite shoes: These shoes are a good alternative to metal shoes. Composite shoes are closer - or match - the mechanical properties of the hoof keratin, therefore allowing the entire hoof capsule to flex in various dimensions as it should. It is easier to transition from plastic shoes to leaving a horse barefoot than with metal shoes, provided that the horse is a candidate for being barefoot.

Working with your Farrier and Veterinarian In general most hoof care providers (farriers and hoof trimmers) are reasonable people and try to do what is best for the horse.

They tend to be bombarded by a lot of conflicting ideas on how to approach hoof care, as a result they may not at first be open to trying something different. If you need to make changes or want to try another hoof care system, try to handle the situation in a diplomatic way. Hoof care providers do not always have the luxury to work with radiographs and often are missing information about the hoof. Ideally, a hoof care provider should be able to take radiographs while trimming and shoeing. These radiographs should not be used for diagnosis purposes, but to check internal landmarks, like sole depth, shape of the pedal bone, state of the sole arch, etc.

Figure 8: Example of a “crazy contraption� that I think should be avoided.

Unfortunately, we are a long way from having any regulation that would allow hoof care provider to take radiographs for trimming purposes (and rules vary from state to state). Ideally, horse owners should go to a veterinarian once a year to have a complete hoof evaluation. Based on that evaluation, both veterinarian and hoof care provider should be able to work together. Veterinary medicine deals with diagnosing specific symptoms, while a hoof care provider deals with mechanical issues, and there can be some conflict between the two approaches. In my opinion, one needs to solve hoof problems from both angles. You, the horse owner, need to feel that the approach and proposed solution make sense. Use your common sense and don’t let anyone talk you into some crazy contraption on your horse’s feet (see figure 8!)