The Trouble With Mud
Perpetual mud and moisture can make hooves more deformable under weight-bearing pressures.
When the going gets muddy, the muddy get hoof problems; here's what to look out for.
Horses’ hooves are finicky when it comes to moisture. In arid environments they tend to dry out, and in wet conditions they become too soft. If you had to choose between the two, however, dry would probably be the winner.
Continuous exposure to moisture can cause a long list of hoof problems, ranging from difficult-to-manage soft, sensitive feet that won’t hold their shape or nails, to various types of damage and infections in the capsule and its structures. Then there are the injuries due to slipping and scrambling in deep mud or bad footing, lost bell boots, and pulled-off shoes. In short, keeping horses’ feet sound and healthy can be a difficult challenge when weather is wet and footing precarious.
Moisture’s Effect on Hoof Structure
Simply put, “feet tend to lose their shape when they are constantly wet,” says Paul Goodness, senior member of a group farriery practice based in Round Hill, Virginia. “They become flatter and wider, which may be nature’s way of giving them more surface to not sink so deeply in the mud.”
Survival tactics aside, the hoof’s horny tissues—frog, sole, bars, and walls—do this because the moisture makes them more deformable under normal weight-bearing pressures. And when the outer structures start to fail, the inner structures become overloaded and vulnerable to pressure as well, says Steve Norman, a Midway, Kentucky, farrier who shoes many of America’s top Thoroughbred racehorses.
Norman started out shoeing horses in the arid American West. “When I came to Kentucky, the horses’ feet were so soft and waterlogged I could practically push the hoof wall around with my thumb,” he explains. “Horn tubules can become so saturated that the foot starts to collapse,” the sole starts to drop, and then the characteristic foot flare and flattening occurs.
When trimming and shoeing horses in these conditions, Goodness says he prefers to apply shoes to protect the foot so the animal is comfortable on all types of terrain and doesn’t become sore, as well as to help minimize this distortion, flaring, and spreading. “Some farriers may even add a heart bar or some other type of support to help hold the foot together, but you have to be careful when it’s muddy; you don’t want the shoe to be sucked off because there is too much added to it,” he adds.
Horses evolved on prairies; their feet are healthiest when kept away from wet conditions. “Nature designed them for a dry climate, just like she designed them to be moving and grazing all day,” says Julie Bullock, DVM, an equine practitioner and farrier based in Mt. Sidney, Virginia.
Continually wet feet are more vulnerable to issues such as thrush, canker, abscesses, and white line disease. “In our area, frogs tend to recede and almost become atrophied,” says Goodness. “You’d think the constant contact with and support from the ground in soft conditions would aid the frog, but the opposite seems to happen. I think the constantly wet frog becomes more susceptible to pathogens.”
The muddier it is and the more traction the horse needs, the bigger the calk your farrier likely will use. Goodness notes that fewer people request heel calks for their horses than they did in the past, but it can be an effective safeguard against horse—and human—injury, noting that if a horse doesn’t have quite enough traction, he might slip out from under you or fall down.
Heather Smith Thomas
Our sources list some of the conditions and issues commonly seen in mud- and moisture-laden hooves:
Sole bruising Persistent water and mud exposure can make hooves more susceptible to sole bruising—even from small stones—and Goodness says barefoot horses in particular might become tenderfooted.
Thrush This anaerobic (able to survive with little to no oxygen) bacterial disease affects the frog and surrounding sensitive tissues, can be painful for horses, and difficult to clear up if feet are constantly wet, Goodness says.
White line disease The anaerobic bacteria or fungi that cause this condition can creep into and infect the inner nonpigmented space within the hoof wall, particularly with constant mud exposure, notes Goodness. “Someone mapped out the incidence of white line disease and it was clearly more prevalent in humid regions,” he says.
Abscesses These localized accumulations of pus within the horse’s hoof are common in soft, permeable feet; sand or small bits of gravel and debris can penetrate the sole or the white line. “Flares create separation; foreign material gets pressed up in there and may create an abscess,” Goodness explains. “This past year we’ve treated more abscesses than ever because the first half of the year was wetter than we’ve seen for a long time.”
Scratches This lower limb issue, also known as pastern dermatitis, dew poisoning, or greasy heel, involves painful inflammation and lesions around pasterns that are exposed to moisture and mud. “There are several dermatological conditions that may appear (scratches could be caused by a number of pathogens),” says Bullock. “For those you should call a veterinarian because the horse may need antibiotics, and in some instances might need systemic antibiotics versus something topical. The hair may need to be clipped away and the lower limbs scrubbed and then kept clean and dry.”
Lost shoes Shoes can slip off if hoof walls are too soft to hold nails effectively. Says Mike Pownall, DVM, an equine veterinarian and farrier at McKee-Pownall Equine Services, in Campbellville, Ontario, Canada, mud is the bane of a farrier’s life. “It means shoes that suck off easier, especially if they have pads,” he says. “There is nothing more frustrating after you’ve done a beautiful shoeing job or patched a foot or made a special shoe for a certain condition, and then the horse is turned out in the mud and loses it.”
If the shoe can’t be found, you then have the risk of that horse or another stepping or rolling on the mud-buried, nail-riddled piece of metal, potentially creating a puncture wound.
“To help keep shoes on, I use clipped shoes,” says Bullock, which are those made with thin metal pieces that hug the hoof wall and help stabilize the nailed-on shoe. “I ride endurance horses and fox-hunting horses and always shoe them with clips.”
Along with fostering an environment amenable to hoof-harming pathogens, muddy terrain can also cause horses to slip, slide, and injure themselves. Horses in slick footing might scramble to keep their balance, making them more apt to hit themselves or step on one shoe with another foot and jerk it off.
“If footing is slippery horses take shorter strides and tense up and try not to fall down,” Goodness says. “In the mud we fit shoes a little shorter and tighter (with less sticking out at the heel and quarters) to keep them on. This works great in the mud, but it may not be so good when you take the horses out on the trail or work in dry conditions with the shoes a little too small and too tight.”
Herein lies one of a farrier’s challenges when trying to shoe horses in muddy conditions: Keeping heels healthy with shoe support and striking a balance between concussion and hoof expansion. “A farrier tries to do something in the middle—to keep shoes on in the mud and still reduce concussion problems,” Goodness says.
The muddy season introduces yet another factor: Goodness sees more coffin bone fractures during this time. “I think the feet sink deeper into the mud, and if they hit a rock down there they may be at risk for fracture,” he explains.
Suppose your horse’s paddock is a perpetual boggy mess and you’ve grown accustomed (albeit begrudgingly) to sacrificing Wellies to it daily. All is not lost: If your horse’s paddock is completely mud-filled, you can create a mound using rocks, gravel, or solid footing where he can get out of the muck, Pownall suggests.
“You just have to be careful if you have a lot of rocks (for footing) to make sure they don’t get caught in a shoe,” he says, and remember there’s always the risk of bruising on sharp rocks.
Some people scatter shavings in muddy paddocks to help create dry areas. “This can be counterproductive if you use pine shavings and they get tromped into the mud and manure,” Bullock warns. “Pine is acidic, and along with manure and urine this makes a very acidic environment for the feet, which is hard on the hoof horn.”
For a more permanent solution to your mud problems, consider installing high-traffic area pads (typically made of geotextile fabric, crushed stone, and a dense grade aggregate) around gates or watering areas. These smooth, dry surfaces require some initial cost, but can provide years of mud relief in high-traffic areas (see TheHorse.com/29345 for more info).
You can also prevent muddy-paddock casualties simply by monitoring your horse’s feet regularly. If you are checking feet you’ll know if they need attention and can address small problems before they become larger ones.
“Sometimes there is nothing you can do about the mud, and it may help to use a hoof dressing to seal out moisture,” says Pownall. “Moderate use of hoof dressings may be beneficial, such as once or twice a week. If you overdo it, however, the hoof starts to rely on the artificial protection and this may be counterproductive.”
Also be wary of bringing your horse in and out of muddy environments frequently. “When the horse comes out of the mud—into a barn or pasture that’s not muddy—then the mud dries on the hoof,” says Pownall. “If it’s a clay-type mud, it draws moisture from the hoof wall and starts to dry out the foot. It’s better for horses to either stay in the mud or out of it, because when they go back and forth, back and forth it’s hard on feet.”
That goes for wetness in general, as well. Think of what happens when you wash a bunch of horses in one afternoon and your hands are wet and dry repeatedly; the skin tends to chap and crack. Pownall believes this back-and-forth between wet and dry is the horse’s biggest challenge because it can create cracks in the hoof wall.
Keep a close watch on your horse’s feet this soggy, slick season as spring and summer rains shower. Employ regular farrier care and call your veterinarian at the first sign of a moisture-related problem brewing. A hoof-tissue-eating pathogen or strained ligament can quickly put a damper on your horse’s comfort and your riding plans.
About the Author
Heather Smith Thomas ranches with her husband near Salmon, Idaho, raising cattle and a few horses. She has a B.A. in English and history from University of Puget Sound (1966). She has raised and trained horses for 50 years, and has been writing freelance articles and books nearly that long, publishing 20 books and more than 9,000 articles for horse and livestock publications. Some of her books include Understanding Equine Hoof Care, The Horse Conformation Handbook, Care and Management of Horses, Storey's Guide to Raising Horses and Storey's Guide to Training Horses. Besides having her own blog, www.heathersmiththomas.blogspot.com, she writes a biweekly blog at http://insidestorey.blogspot.com that comes out on Tuesdays.