From the founder-prone chubby pony to the chronic, endocrine-related laminitis case, here’s how to keep your EMS horse comfortable.
It’s morning turnout time, and your easy-keeping Welsh pony isn’t quite himself. He hesitates before stepping out of his well-bedded stall onto the hard concrete, so you figure he’s a little foot-sore. After a few days of stall rest and some veterinarian-prescribed Bute, he’s sound. You chalk it up to a foot bruise.
In reality, your horse could have just suffered a small bout of laminitis (inflammation of the laminae/lamellae—the interlocking leaflike tissues attaching the hoof wall to the coffin bone) tied to an as-yet undiagnosed case of equine metabolic syndrome (EMS). And it might not have been his first.
“The problem with the endocrine case is that there is cumulative damage over time—often for many years,” says Amy Rucker, DVM, an ambulatory veterinarian in Central Missouri who has a special interest in equine feet. “The first time the owner recognizes that the horse has laminitis might not be the first time the horse had the problem.”
So how can you recognize when a horse is at risk for developing EMS-related laminitis? And what can you do to either prevent or manage it so he stays sound? Let’s find out.
Pinpointing the Problem
The terms equine metabolic syndrome and pituitary pars intermedia dysfunction (PPID, or equine Cushing’s disease) often go hand-in-hand. And they’re frequently accompanied by conditions such as laminitis and insulin dysregulation (ID, which is either hyperinsulinemia, excess levels of insulin in the blood, or insulin resistance, a decrease in tissue sensitivity to insulin). So what’s the connection between all these words?
Equine metabolic syndrome and PPID are both endocrine disorders that can negatively affect insulin levels and lead to laminitis. Horses and ponies with EMS produce too much insulin in response to feed and are often (but not always) overweight. Pituitary pars intermedia dysfunction affects horses and ponies as they age and can have similar effects on insulin regulation. Both conditions develop so gradually that by the time owners notice and veterinarians diagnose them, many horses are already suffering from the effects of laminitis.
“The problem we often see with endocrine-related laminitis is that it often develops insidiously and quietly,” says Andrew van Eps BVSc, PhD, MACVSc, Dipl. ACVIM, associate professor of equine musculoskeletal research at the University of Pennsylvania’s School of Veterinary Medicine, in Kennett Square. “By the time the owners realize there is a problem, they are often shocked at how advanced it is before the horse actually shows any lameness or outward abnormality.”
For this reason, he says, owners of horses at a higher risk of endocrine-related laminitis (e.g., ponies, Morgans, Arabians, and Warmbloods; horses that are obese and/or have regional fat deposits) should have their veterinarians perform initial blood tests to screen for ID (and PPID in older animals), followed by regular repeat testing.
Farriers can also help identify at-risk horses before laminitis sets in. “As farriers, we see the horse more often than the veterinarian,” says Travis Burns, lecturer and farrier at the Virginia Maryland College of Veterinary Medicine at Virginia Tech, in Blacksburg. “If a horse starts to gain weight or become a little tender-footed, we can help the owner realize there is a problem. If the horse becomes insulin-resistant or stays in a chronic state of inflammation, the feet will drift too far in the wrong direction and we won’t be able to stop the damage.”
Look for subtle changes in weight, body condition, and hooves, as well as signs of a metabolic issue, such as a cresty neck or a thickened hair coat that doesn’t shed normally.
Critical Early Intervention
The key to managing an EMS horse’s feet and warding off laminitis lies within. “If you have a horse or pony that fits into the high-risk category for laminitis, it’s worthwhile to get X rays of the front feet occasionally, at the guidance of your veterinarian, just to see what’s going on,” says van Eps. “By the time there is pathology (disease or damage) in the foot, it’s often too late. What we’ve found over the years with laminitis is that once a horse experiences this, the changes in the feet are essentially irreversible. The feet can be managed, but there is only so much you can do. Thus, prevention and limiting progression of the disease is key.”
With horses prone to endocrine disease, Rucker says she typically takes lateral (from the side) radiographs annually as part of a preventive health program.
“We also measure the width of the hoof wall, which includes the hard outer horn and also the soft tissue—the lamellae and dermis,” she says. “The distance from the outermost point of the wall to the coffin bone is made up of the horn and lamellar dermis. We can compare this width/depth from year to year, to make sure it hasn’t changed and the horse isn’t starting to develop clinical laminitis.”
She says she tries to help owners become more aware of potential problems and talks to them about the fact their horses are overweight or might be prone to endocrine disease, relying on both foot and blood monitoring to try to identify cases before a major problem develops.
Subtle Signs of Trouble
You and your farrier can monitor a variety of aspects of your horse’s hooves, not the least of which are his white line and sole. In addition to laminitis, EMS horses are prone to white line disease (an infection of the inner hoof wall tissues) and abscesses, the former of which is particularly tricky to manage.
Your farrier might notice that the white line in your horse’s front feet is getting wider or that the sole’s natural arch is flattening. The horse used to be comfortable when the farrier worked, but now, when he or she picks up one foot, the horse doesn’t want to stand on the other for very long. “All these things point toward the fact that this horse has a problem,” says Rucker. “It might be laminitis or something else, but these are the kinds of things we watch for.”
If white line disease has set in, your farrier will debride (remove the dead and damaged tissue) the affected area to expose it to UV light and air. You can then take steps to keep the feet clean and dry and treat the debrided pockets topically with astringents.
Also pay attention to your horse’s hoof growth. “If the heels are outgrowing the toe—with uneven hoof growth—this is also a clue,” says Rucker. “The owner can help keep track of this, looking for a wide white line or a flattening or prolapsed sole and checking growth rings of the hoof. If those rings are wider at the heel than at the toe, these are things that suggest the horse is having a problem.”
And, of course, there are the telltale signs of an early case of laminitis: an increased pulse in the feet; the horse not wanting to walk forward or turn because his feet are sore; and shifting weight from foot to foot.
Once you notice changes, Burns says the principles of hoof care for these horses are simple. “We just go back to basics to maintain as much sole depth as possible, to keep the horse comfortable,” he says, adding that horses with insufficient sole depth become sore and tender very readily.
He says he’ll also trim the horse’s toe back to make sure the dorsal (outer/front-facing) hoof wall aligns with the dorsal surface of the distal phalanx (coffin bone) and take steps to relieve the stress and strain on the lamellae interface between the hoof wall and its inner structures.
Horses with EMS can suffer from either acute laminitis attacks (often when first diagnosed with the disease) or chronic soreness from earlier laminitic damage.
“A horse with an acute bout needs to be handled differently than a chronic case, and the chronic horse needs careful management for the rest of his life,” says Rucker. “If you think the horse is having an acute episode, whether it’s had laminitis in the past or not, the main thing is trying to control/halt the laminitis. This might include endocrine management. We may use various medications (such as metformin, pergolide, etc.) to try to get the endocrine disease under control, along with dietary management. We also restrict exercise because we don’t want the unstable lamellae falling apart further.”
It’s important to provide affected horses soft footing to help support the foot, so the hoof doesn’t meet resistance during movement. “I generally just get the horse into a deeply bedded stall,” says Rucker. “This provides cushion and give, and the deep bedding also encourages the horse to lie down and get off his feet.”
Similarly, van Eps says he keeps acute cases confined during early stages of laminitis, explaining that damaged lamellae are weak for a period of time and vulnerable to further damage.
“What you do to the bottom of the feet is not as important during that (acute) period as making sure the horse isn’t stressing the feet by moving,” he says. “We can make the horse more comfortable by providing some sort of cushioning that supports the frog and sole and takes some of the weight off the hoof wall, but the best support is sand because it conforms to the bottom of the foot. It supports the foot because it packs in and evenly distributes under the foot, and when the horse turns it allows the inside foot to pivot easily, without gripping the ground.” This give and easy movement put less stress on those inner attachments.
“The other thing that sand does is ease breakover,” says van Eps. “When the foot breaks over, the toe can dig in; the foot can pivot with less stress on the lamellae.” With this level of comfort and easy breakover, there’s less need for a special shoe.
Your farrier can provide your horse with similar support using dental/silicone impression or other hoof cushioning materials, van Eps adds. He also suggests using ice boots to cool the feet continuously for the first couple of days of an acute bout of laminitis to help reduce pain and inflammation.
If your horse seems more comfortable after a few days of confinement, however, don’t relax. “The old rule of thumb was to confine them a week for every day that they are lame,” says van Eps. “If the horse is lame for five days, he needs to be confined for five weeks. This seems like a long time, but it guarantees that this episode will be over and the tissue will have some integrity and strength again before the horse stresses it.” Then the compromised lamellae, which stabilize and repair to an extent (though never to normal) over time, will be more likely to withstand the pressure of weight-bearing.
After the first month or so, once the acute phase has passed and the horse enters a chronic phase, he might benefit from a more permanent hoof attachment. “Some type of easy-breakover shoe, with support material for the frog and rear portion of the sole can be very helpful,” says van Eps.
“There are a lot of options,” he continues. “What’s best will depend on the foot. This is why it’s important to work with a farrier and (be sure he or she has) access to the veterinarian’s radiographs. Some horses and ponies, if they just have a little rotation of the coffin bone at the toe, benefit from simply lifting/unweighting the sole area underneath the tip of the bone. This can be as simple as just a regular shoe or a shoe with a heart bar to redistribute some weight off the wall onto the frog.”
As the chronic case stabilizes, Rucker says she then allows the EMS horse to do light exercise to try to control his weight.
Designing a Shoeing Regimen
Indeed, veterinarians and farriers use many types of shoes and materials to help support and minimize stress on these horses’ delicate hoof structures.
“In shoeing, we are only limited by our own creativity,” says Burns. “The farrier can utilize any number of shoes on the market today—from clogs to EasyCare shoes that are wide-webbed. The principle is simply to ease movement in all directions, and the specific technique is up to the farrier or the owner’s finances or what the individual horse might need.” Simply, no one shoe works for every horse.
Equipped with a set of hoof radiographs as his or her blueprint, the farrier can see where the coffin bone is positioned and how the hoof angles look. A close veterinarian-farrier relationship is quite valuable at all stages, but especially this one.
“We work together,” says Rucker. “I’ll X ray the horse, and then we’ll trim the foot,” and check sole depth on X rays after. “How is the position of the coffin bone in relationship to the ground?” she says. “We measure all those things.”
Armed with this information, shoeing methods might include rolling or rocking the toes, applying the wooden clog shoes Burns mentions to help ease breakover, and/or applying pour-in pads or impression material to support the sole.
“When the farrier is done we do another X ray to see if we accomplished the goal and got the breakover where we wanted it,” Rucker says.
When the horse’s shoes are ready to be reset, about six weeks later, Rucker recommends veterinarians take follow-up radiographs to monitor hoof changes and make sure the horse is progressing properly.
“Then you can develop a long-term plan for the care of those feet,” she says. “We can see whether this shoe worked or didn’t work and whether we need to try something different or tweak it a bit. The plan evolves as you go along.”
Horses with EMS (as well as insulin dysregulation and PPID) tend to be prone to developing laminitis. Early diagnosis of the root problem, careful monitoring, and appropriate hoof care can help keep these at-risk horses comfortable.
“Aside from the hoof care, we need to figure out why the laminitis is happening, because we need to address the root cause,” says van Eps. “This is the only way we can keep it from becoming an issue again. This should be the primary objective. For years, we’ve tried to fix these horses and ponies with shoeing/trimming management alone and failed over and over again.”
Work with your veterinarian and farrier to not only manage your EMS horse’s feet but also his lifestyle to ward off future laminitis episodes.