Q.I keep my Western pleasure horse’s front feet shod year-round so he can stay in work during the winter and to keep his hooves in decent shape; otherwise they tend to flare and crack. During our main riding season (March-late October), he’s on a six-week trim and reset schedule. But during the winter, when all our other horses’ hoof growth slows, his doesn’t—the farrier jokes that he could be trimmed every three weeks. What could be causing his hooves to grow so fast, and why would it be different from the other horses? They’re all on the same diet, exercise schedules, etc., they just have different genetics.

—Via e-mail

A.Hoof growth, be it fast or slow, is a common discussion among horse owners, trainers, and veterinarians. On average, an adult horse hoof grows from the coronary band to the ground surface in one year. Younger horses’ and foals’ hooves grow much faster.

There are several factors that could affect hoof growth rate among a group of horses in the same barn and management regime. Age is an important and consistent factor, but also, as mentioned in your question, genetics can be one of the biggest factors. Some horses just seem to grow hoof faster than other individuals, even those of the same breed. As a general observation, hardier breeds and more robust-footed horses seem to grow hoof faster than average.

You mentioned your horse population all had the same diet and exercise program. Intestinal macro- and micronutrient uptake can be quite different between horses, and this is a potential unseen cause for your Western pleasure horse’s hoof growth. He might just have a more efficient uptake of the nutrients influencing hoof growth. Horses that have a less efficient or incomplete nutrient uptake might benefit from an increased amount of hoof building blocks available in their diet to promote improved hoof growth and quality. Some common additives to hoof supplements that might help achieve this are biotin, methionine, cysteine, copper, and zinc, among others such as vitamin E derivatives. Increased metabolic rate, heart rate, and regular exercise can affect hoof growth, as well.

It does not sound applicable to your horse, but some pathologies can greatly influence hoof growth, as well. Laminitis, even subclinically, can alter the growth rate or even cause different rates within the same hoof capsule—the toe might grow slowly while the heels grow more rapidly, for instance.

Lastly, hoof conformation and health play an important role in how quickly they grow. A well-balanced and appropriately trimmed hoof with good sole depth stands a better chance of achieving healthy rapid growth than one that is compromised in some manner. A very thin-soled hoof, for instance, might be compressing the blood supply to the tissue that grows the sole, which could lead to a downward spiral of even thinner soles and increased stress to that hoof.

Another hoof conformation topic that has gained a lot of attention lately is negative palmar (front limb) or plantar (hind limb) angles (the angle the coffin bone makes with the ground; a negative angle means the back of the coffin bone is lower than the front of the bone, rather than both ends being level) of the coffin bone. This is best diagnosed with radiography but external visual signs can give clues to the presence of this problem. A steep coronary band angle; low heels; and a long, often “bull-nosed” toe are hallmarks for this condition. Negative palmar or plantar angles can cause the toe to grow much faster than the heels; in some cases, it can seem as though the whole hoof is growing rapidly, but the heels aren’t keeping up with the toe and problems or lameness often result.

Finally, be mindful that increased wear in a barefoot horse could offset the perceived growth rate, and without external markings such as a crack or defect, it can be challenging to visualize the rate at which the hoof is actually growing out.