Grand Prix Guidance

Grand Prix Guidance Using Radiographs to Trim and Shoe

by Mark R. Baus, DVM

Whether you know it or not, your horse has experienced hoofrelated pain during his or her athletic career. It’s commonly recognized that the horse’s hooves, especially the front hooves, are vulnerable to many external and internal forces. In short, it’s where the rubber meets the road. Fortunately, we can control how these forces act on the hoof with a careful evaluation of the relationship between the skeleton of the lower limb and the hoof.

How do you know your horse’s hooves are causing a problem for you or your horse? If your horse is lame, and the source of the lameness is isolated to the hoof with diagnostic nerve blocks. But painful front or hind hooves can manifest in multiple different ways other than obvious lameness. Does your horse lose shoes for no apparent reason? Does your horse trip or stumble periodically? How about forging? All of these are indications of a potential imbalance in the horse’s hoof.

Radiographs of your horse’s hooves can be an invaluable guide to determine the best way to trim or shoe your horse. This process is reliable, and the X-rays are easily obtained.

Let’s start with a few definitions: Sole depth: Measured from the tip of the coffin bone to the bearing surface of the hoof (the ground). Ideal sole depth is 15 mm give or take a couple mm. Too little sole depth and the hoof is vulnerable to bruising. Too much sole depth and the hoof is likely too long, causing tripping, lameness, and other problems (see photo 1).

Heel height: Measured from the back of the coffin bone to the bearing surface of the hoof. Ideal heel height is compared to sole depth. If it does not measure longer than the sole depth, there is a negative coffin bone angle and if there is less than 10 mm of heel height, the digital cushion is likely affected.

Negative coffin bone angle: A negative coffin bone angle is usually caused by inadequate heel height (see photo 2). Ideally, the coffin bone has a slight upward angle compared to the hoof (usually 2–5 degrees).

1.

2.

Latero-medial heel balance: This is a measurement of the height of each heel and, ideally, they are even. Horses that

are base-wide and toed-out (the vast majority of all horses) tend to put more weight on their medial or inside heel. Horses that are toe-in are the opposite, tending to put more weight on the lateral or outside heel. The extra pressure on one heel versus the other causes that heel to wear faster and, subsequently, lowers that heel. Therefore, most horses have a lower inside heel compared to the outside heel. Uneven heels can have a deleterious effect on the lower joints (see photo 3).

Breakover: The most important measurement is how far forward the toe is. Breakover defines when the hoof starts to break over with each step. The heel should leave the ground first as the horse moves forward and the hoof rolls over. The breakover is when the last part of the hoof, ideally the toe area, leaves the ground, which is why toe length is important. A long toe causes the breakover point to slow, creating extra work for the tendons and ligaments.

This is critical for horses that forge or pull shoes, but it is even more critical for horses with problems in the coffin joint and navicular region. Breakover is measured by dropping a vertical line down from the tip of the coffin bone and by measuring from this point forward to the front of the toe or shoe. The ideal breakover with this measurement is between 0 and 15 mm ahead of the tip of the frog (see photo 4). ONCE A HOOF-RELATED problem is identified, some changes may be necessary to improve lameness or to return to peak performance. What have we neglected to mention here? Our farrier. It’s all well and good that we come up with suggestions for improving your horse’s hoof, but the farrier will also have a valid opinion about this. Undoubtedly your farrier will want to be a part of this discussion as he or she plays a key role when it comes to trimming the hoof and applying the correct shoe.

Before proceeding with hoof radiographs, it’s important to know how your farrier wants to be involved in the process. Ideally, he or she is present when the radiographs are taken. Alternatively, the radiographs can be emailed to the farrier. Regardless, open communication is paramount to determine the best course of action before any final decisions are made.

What is our most common hoofrelated problem? The horse with low heels, low hoof or coffin bone angles, and long toes. The cause of this problem goes beyond the hoof wall conformation that the horse inherited. Conventional horseshoes work well in most situations; however, they tend to preserve the hoof wall at the toe but less well in the heels.

Active horses and the natural movement of the heels cause the heels to wear much faster than the toes. The horse with

3. 4.

low heels is much more prone to bruising of the heels. If the heels are significantly low, the digital cushion is compromised and is another source of heel pain.

Since the toe does not tend to wear down, the worn heels cause a negative coffin bone angle. Negative coffin bone angles create added strain on the deep digital flexor tendons. This added strain takes a toll on the navicular bone and associated structures. Negative coffin bone angles also put compressive forces on the front of the coffin joint.

Although we tend to regard issues of the coffin joint and navicular bone as manageable or inevitable problems, we can prevent or manage these conditions with close attention to hoof angles, sole depth, heel height and breakover distance. If you are wondering if your horse needs help with his hooves, contact your veterinarian and farrier to see if radiyographs would be helpful.

Katie Hylen Mark R. Baus, DVM founded Grand Prix Equine in 2009. He’s provided care to horses in the same region and for many of the same clients for more than 30 years. Mark began the Connecticut Equine Podiatry Group to foster relationships between farriers and veterinarians.

Read back issues and subscribe!

Containerized Manure Removal

Containers from 4 to 30 cubic yards . Farms with one horse to 100!

Associated Refuse supplies manure removal containers in Fairfield, New Haven, and Litchfield Counties in CT, Westchester and Putnam Counties in NY Our container sizes range as follows 4, 6, 10, 12, 15, 20, and 30 cubic yards. Please inquire about delivery and pickup guidelines as well as service area. Newtown, Connecticut 203-426-8870 info@associatedrefuse.com associatedrefuse.com