Q My horse’s hooves are quite dry. Some people say they should be soaked. Others say it’s better to keep hooves as dry as possible at all times. Which approach should I take, and what else can I do to maximize the health of his feet?
AMANDA WIDMAN, Colorado
A Most of the U.S. is temperate, and Mother Nature does a great job of regulating the hoof’s ability to adapt. Only in extreme climates—such as the rainy Pacific Northwest, or the hot, dry Southwest—should horse owners intervene, and then only to help moderate the effects of the climate.
In extremely wet climates, hooves can’t dry out, and the bottom of a hoof provides access for a variety of bacteria, especially if a frog is over-trimmed. So in rainy climates it’s necessary to provide horses with a way to stand on dry footing at least part of the time.
In desert climates and drought conditions, the sole of the hoof naturally becomes flatter and thicker for the purpose of protection. I recommend providing shade in such climates, as hooves can get hot and that can lead to laminitis. I don’t, however, recommend soaking hooves that’ve developed in dry conditions. They’ve already adapted, and soaking won’t necessarily benefit them. Moreover, especially if the soaking is done improperly, it can provide a medium for bacteria to grow in the central sulcus (cleft in the middle of the frog) or collateral grooves (clefts alongside the frog).
I believe that over-trimming in any climate is detrimental to the hoof’s natural ability to regulate moisture. A horse’s hoof is equivalent to a human’s fingernail, made up of keratin, and cutting or filing away too much can strip its waterproofing and make it vulnerable to drying out.
The outermost layer of hoof wall, the stratum externum or periople, is only a fraction of a millimeter thick, yet it protects the stratum medium (the majority of the hoof wall) and stratum lamina (the innermost layer). The periople gives the hoof that gray, waxy appearance when it’s been wet for some time. It’s also the hoof’s natural waterproofing and so should not be filed away, though some farriers mistakenly do so to give the hoof a clean, finished look.
The sole of the hoof is hard keratin, and the frog consists of a softer keratin. A healthy hoof should have a frog that’s firm yet moveable under pressure. Trimming away too much frog, a far too common practice, removes the outer layer of keratin and makes the moister inner layers susceptible to drying out. The frog then loses resiliency and becomes more like a hard piece of plastic, unable to cushion as it should. It also hastens the drying out of the hoof. Similarly, over-trimming the sole not only thins the sole, but also dries it out, too.
The dirt plug that builds up under the hoof is important as well; it helps protect the foot plus it increases the surface area of support across the sole, somewhat like a sneaker giving a larger base of support to a human foot. In addition, the dirt plug helps keep the hoof from drying out. Horses that are free to move around keep adding and losing their dirt plugs, but this doesn’t happen with confined horses. So these plugs should be left in place unless a horse is confined and gathering too much static manure and urine under the foot.
ROBERT M. BOWKER, VMD, PhD
Professor, Veterinary Teaching Hospital
Michigan State University