Tending To A Tender Foot

Although the equine hoof is a marvel of resiliency, it's not made of rubber, or titanium, or diamond. As a living structure, it has its vulnerabilities, and when faced with unusual stresses, it shows them. Stone bruises, those reddish-purple (on a white hoof) or dark gray (on a dark hoof) spots sometimes visible on the soles of your horse's feet, especially right after the farrier's knife has removed the surface crud, are one of the most common signs that the hoof has taken some abuse. But by the time you see the bruise, it's just a reminder of a long-past trauma; the injury is already several months old.

Fortunately, stone bruises usually aren't serious. When they're fresh, they can cause minor lameness, for a few minutes or a few days. Some horses seem to be able to ignore them better than others. But if a stone bruise happens right before an important competition, it's a crisis. If your horse shows a predilection for repeatedly bruising his soles, it's a chronic problem that you'll want to solve.

Stone bruises generally are the product of your horse's environment. Traveling on hard, rocky ground can batter your horse's soles, especially if he's used to more manicured conditions. (Remember as a kid how you tiptoed very gently over a gravel driveway early in the summer, yelping, "Ouch, ouch, OUCH!" before your bare feet had gotten tough?) But a hard knock against a solid object (a fence rail or a tree root, for instance), can have the same effect. So can shoes that are too small, or those equipped with caulks, grabs, or trailers that alter the foot's natural flight path, or concentrate an unusual amount of pressure on a small area. Hooves that grow up and around a shoe left on too long also can bruise, particularly if the shoe is loose and bangs on the sole with every step. The end result is rather like the aftereffects of your big toenails being stepped on by a Clydesdale, a blooming reddish spot sandwiched between the toenail and the soft tissue underneath.

Certain types of feet seem to be more vulnerable to bruising than others. The classic battered hoof has a flat sole and thin walls (a conformational fault seen in many Thoroughbreds). Concave feet have a better chance of avoiding small, sharp stones because less of the sole comes into direct contact with the ground. A horse with soft feet (common on the wet and rainy West Coast of North America) might be likely to bruise if he's ridden on firmer ground, but a horse with hooves as hard and dry as iron also can be a bruising candidate, since his foot has less natural give than most. Small, upright feet, especially those designated club feet, can gather more than their fair share of bruises.

Feet that are not trimmed and balanced properly can be prone to sole bruising, no matter what their conformation.

Technically speaking, a bruise is the result of the breakage of tiny blood vessels deep in the sensitive tissues of the foot. Blood from these vessels seeps into the surrounding tissues and interstitial spaces (spaces between the cells). When trapped between the hoof horn and the underlying tissue, it is prevented from absorption and can sit there for weeks or months at a time. Eventually, as the sole grows, the blood spot reaches the surface, where it finally becomes visible, one to two months after the fact. Bruises also can occur in the laminae of the hoof, often as a result of a trauma to the coronary band. They'll appear as a purple stain on the hoof wall or the white line, some two to eight months later (the time it takes to grow down from the top).

When a bruise appears in the quadrant of the foot where the heels and bars (extensions of the hoof horn that wrap around onto the sole) meet, it's called a corn. Upright or pinched heels, which cause the full weight of the horse to descend directly onto the heel tissues, are the usual cause of corns, although a horse shod too short can develop them, as can one which has gone too long between shoeings and has to contend with horn that has grown over the shoe, or gravel that has worked its way underneath the shoe's heels. The rounded red spot of a corn might not be noticeable until your farrier pulls the shoe--but the defect should be taken seriously, as it can develop into an abscess if left uncorrected.

Diagnosing Bruises

So, if a stone bruise isn't visible for a month or more after your horse steps on a stone, how do you diagnose a fresh bruise? Certified Journeyman Farrier Wes Goff, of Lindsay, Ontario, says, "That's the real problem with sole bruises. Finding them is largely a matter of experience and gut instinct. A horse who is "ouchy" in his feet, without any other obvious cause, often has a stone bruise--and I suspect it, especially if the horse has a flat foot or thin walls. I ask about his history, too. Where has he been ridden recently, and what has he been doing? A horse with a stone bruise is usually only sore on hard ground, although sometimes sand or dirt from an arena can fill the foot and put pressure on a bruised area.

"I can usually differentiate a stone bruise from a brewing abscess by the feel of the sole. If it's soft, mushy, or is carrying heat, or if the horse is very sore, I start thinking abscess, while a stone bruise is more subtle. It's usually a mixture of signs that tips me off."

There's not much you can do to treat a sole bruise, says Goff, other than rest your horse if he's sore, and take care not to ride him on punishing ground. Generally, the ouchiness will dissipate in a few days. (If you're in dire straits and need your horse sound now, you can consider using a sole-numbing paint such as Sole Freeze, which will allow your horse to perform pain-free for a few hours.) The active ingredient in these paints is phenol, which Goff says you can purchase directly from any well-stocked drugstore. Because phenol is fairly corrosive to skin, however, you�ll want to wear gloves when you apply it--and as it's toxic if taken internally, you'll want to keep it securely capped and well out of the reach of children.

Cold hydrotherapy can be effective, even if it is short-lived. It doesn't make the lesion go away, but it does offer some pain relief. Judicious use of non-steroidal anti-inflammatory drugs as recommended by your veterinarian can be useful.

Protection And Prevention

If your horse is the type which seems to collect stone bruises as a hobby, it might be time to consider some shoeing changes to minimize the time he spends standing in his stall instead of being ridden. First, you might want to ask your farrier to remove less of the sole when he trims your horse. The result won't be as pretty, but the callus left there "will leave him something to walk on," says Goff. You also can try to toughen up your horse�s soles by regularly applying an iodine-based product like Durasole.

Wide-webbed shoes, which cover more of your horse's foot, are the next line of defense, according to Goff. Often, the extra width of metal is all a horse needs to reduce his chronic ouchiness. Many farriers automatically switch to a wide-webbed shoe as their clients' horses go into regular hard work in the summer months (when they'll be most likely to encounter unforgiving, stony ground). If your horse still spends much of his time being ouchy, you'll want to go the next step and consider outfitting him with pads, which will cover the sole and protect him from the elements.

There are dozens of designs of hoof pads on the market, from basic leather (flexible and "breathable," but increasingly hard to get), to various plastics, to amazing high-tech shock-absorbing pads which, while cleverly designed, are expensive and might provide so much flex that they help shoes pop off prematurely. Goff has had his best results with ordinary plastic pads, which are affordable and easy to shape. A squirt of silicon packing underneath helps seal the area between foot and pad and prevents thrush from sprouting in the damp places you can no longer reach with your hoof pick. "I'm not a 'pad person,' on the whole," Goff says, "but some horses need the protection, and if a pad will help keep them from bruising and getting sore, then it's the best solution."

Pads are not a permanent answer, of course--they simply cover up the problem, and there's the disadvantage of not being able to see what's going on with your horse's soles and frogs. However, if you expect to be working your horse on hard, stony ground, pads might work as preventative medicine. In winter, when the ground can freeze into crippling spikes and craters where horses have walked, pads also can be a good idea, especially if they're the kind that helps keep snowballs from forming.

Finally, consider the role of nutrition in your horse's hoof health. If he has chronically thin soles and weak hoof walls, he might benefit from receiving a supplement containing biotin, methionine, and/or zinc, three nutrients that seem to encourage good hoof horn growth. The results will be slow (expect to wait six to nine months to notice a real difference), but the pay-off might be a horse with fewer of those nasty purple stains on his feet the following summer.

About the Author

Karen Briggs

Karen Briggs is the author of six books, including the recently updated Understanding Equine Nutrition as well as Understanding The Pony, both published by Eclipse Press. She's written a few thousand articles on subjects ranging from guttural pouch infections to how to compost your manure. She is also a Canadian certified riding coach, an equine nutritionist, and works in media relations for the harness racing industry. She lives with her band of off-the-track Thoroughbreds on a farm near Guelph, Ontario, and dabbles in eventing.

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