How veterinarians and farriers manage this degenerative arthritic condition
We’ve all been there: We wake up on our day off, which also happens to be the first day we’ve seen the sun in a week. Excitedly, we head out to the barn to tack up for a ride and, instead, find our horse favoring a foot.
Let’s say in this instance, upon closer examination, we notice heat and swelling just above the hoof or, perhaps, even a bony lump. What’s the next step—call the farrier, or call the veterinarian?
The answer is both. As it turns out, veterinarian, farrier, and owner form the optimal team to determine a treatment plan for hoof-associated issues, especially if your horse’s clinical signs lead to a ringbone diagnosis.
“I’m a huge proponent of the team approach to treating ringbone or any hoof-related problem: the owner; the veterinarian, who provides the medical and diagnostic expertise; and the farrier, who offers in-depth insight on shoeing and the mechanical forces of concussion,” says Vern Dryden, DVM, CJF, of Bur Oak Veterinary and Podiatry Services, based in Lexington, Kentucky.
Read on to learn what ringbone is, how your team can work together to diagnose and treat it, and what your horse’s prognosis is if he has it.
The What and How of Ringbone
Ringbone, defined simply as progressive arthritic change that affects the pastern and/or coffin joints (high and low ringbone, respectively), can occur in one or multiple limbs. Although pain from joint inflammation (arthritis) and an immune system on overdrive initially cause the lameness, eventually a bony buildup (hence, the term ringbone) can fuse the joint and relieve it.
Predisposing and contributing factors include conformation, excessive weight, and use. “Horses with extremely upright pasterns or that tend to have an extreme variation, either a valgus (a limb deviating outward from midline) or varus (deviating inward) deformity where they’re collapsing one side of the joint space, can lead to arthritic changes,” says Dryden. “And long-term excessive weight can at least exacerbate these issues once a horse has ringbone. But the most common causes are working on hard surfaces from a young age and injuries to the joint’s cartilage and/or ligaments that lead to osteoarthritic changes in the joint.”
“Most of the cases I see are in middle-aged to older horses,” says Stephanie Caston, DVM, Dipl. ACVS-LA, an assistant professor at Iowa State University, who has studied the use of alcohol injections to fuse arthritic pastern joints (read about it at TheHorse.com/27004). “We see everything from Warmbloods to Quarter Horses and everything in between. I can’t think of one breed or discipline that’s more predisposed to it. I do see some younger horses with ringbone, but like with people, arthritis is usually associated with wear and tear on joints, so it takes some time to develop.”
If your horse’s conformation lends itself to developing ringbone, Dryden suggests avoiding heavy or constant work on hard surfaces and shoeing to improve any structural deficiencies. “There are many different ways to approach it,” he says. “You might want to use pads between the hoof and the shoe to decrease the vibratory forces and concussion or use a synthetic shoe.” As with any health–related condition, your veterinarian can best assess your particular horse’s needs.
The Diagnostic Process
When your veterinarian arrives to determine the cause of your horse’s lameness, he or she will begin with a thorough physical exam, including taking vital signs (temperature, pulse, and respiration) and inspecting the limbs visually and manually for heat, swelling, and a digital pulse. “Horses with ringbone will often have that telltale firm, bony swelling around the ankle area,” says Caston. However, adds Dryden, often you’ll notice lameness before bony proliferation occurs.
After the physical exam, your veterinarian will watch the horse’s gait while you or an assistant jogs him, before and after flexing the lower limb to move the coffin, pastern, and fetlock joints (called a flexion test). “It’s very difficult to isolate among those three, but if the horse becomes more lame at that point, you’ll know you’ve at least isolated the lameness to that general area,” Dryden says.
Your veterinarian will follow up by blocking certain nerves (systematically injecting them with anesthetic until pain is eliminated) to pin down the origin of pain more closely. “I’d start with a palmar digital nerve block that would typically block (pain and lameness in) the heels and most of the foot,” says Dryden. “But in many cases, that’s going to block some of the pastern region, as well, due to diffusion of the anesthetic. I’d follow that up with an abaxial nerve block, which is placed at the base of the proximal sesamoid bones (located at the back of the fetlock) to numb the structures below the fetlock and which often blocks some of the fetlock, as well.”
Dryden says that if nerve blocks and pastern swelling indicate something significant there, he’d follow up with radiographs.
“In some cases,” he adds, “the blocking pattern makes it difficult to localize the lameness, so I might also do an intra-articular (anesthetic injected directly into the joint) block. If that blocks out within a short time, then that’s a very, very, very definitive diagnosis that the problem is within that pastern joint.
“At that point,” he says, “we’d go to radiographs to see if there are any osteoproliferative (bone-deposit-forming) changes or minimization of the joint space.”
“It’s pretty easy to identify those changes associated with arthritis on the films,” adds Caston. “Most of the time, diagnostics will consist of X rays. But if we don’t get an answer with X rays, we can do MRI, bone scans (aka nuclear scintigraphy), or ultrasound. Unless it’s a very early case, you probably wouldn’t have to go to those advanced imaging methods.”
Once your veterinarian determines the exact location and degree of the horse’s ringbone, he or she will discuss treatment options with you.
Ringbone is a chronic degenerative condition, so rest will not resolve it. “In fact,” says Caston, “it may even make your horse more sore, especially if he’s cooped up in a stall where he can’t exercise freely and so may get stiff or gain weight.”
After diagnosis your veterinarian and farrier can consult to come up with shoeing options for your horse. Although special shoeing won’t cure or halt ringbone, Dryden says it can slow the progression by preventing excessive joint movement and, thereby, keep your horse more comfortable.
Paying close attention to hoof angles can help. “A hoof angle that’s excessively upright or excessively low can be problematic for these cases,” Dryden says. “An upright hoof capsule doesn’t absorb concussion well and transmits vibratory forces up the limb. When angles are too low, it’s hard to create a nice alignment with your horse’s bony column (the coffin and pastern bones).”
He adds that shoes for horses with ringbone should promote easy breakover (the moment the heels lift off the ground). “We can reduce mechanical leverage on the joint space by bringing the breakover back toward the center of the foot,” he says. “One of the old shoeing prescriptions I used 20 years ago was to take a shoe, shape it to the foot, and then take another shoe a size or two smaller and weld it in the center to create a sort of step, which made it easier for the hoof to break over and reduced torque on the joint.”
Now, he says, in addition to this and other techniques farriers use with similar goals, some aluminum shoes have an aggressive breakover built into them to reduce leverage.
Just as better breakover can help, so can minimizing concussion during shoeing. “Farriers will notice when they go to nail a shoe onto these horses that the horse definitely doesn’t like the process,” Dryden says. “They get irritable because they’re anticipating that hammering. So changing the shoe to minimize concussion is very logical. Adding a plastic or rubber pad between the shoe and foot or a silicone or polyurethane pad also helps reduce concussion. Or you can go to the other end of the shoeing protocol spectrum and use synthetic glue-on shoes that don’t need any hammering.”
Pain relief is front and center when treating horses with ringbone, and non-steroidal anti-inflammatories (NSAIDs) often provide the first line of defense. The most commonly used are phenylbutazone (Bute), flunixin meglumine (Banamine and others), ketoprofen (Ketofen and others), and firocoxib (including Equioxx).
“Any of these typically will help a horse with arthritis be more comfortable,” says Caston. “Most people are going to be using Bute. It’s the most common, it’s cheap, it’s readily bioavailable to the horse, and has good distribution (to the digit).”
Dryden adds that in the short term Bute is great, but for the long term he prefers firocoxib. “It’s easier on the horse’s gut because of its ability to selectively inhibit certain cyclooxygenases (COX, a type of enzyme) for prostaglandin (a pro-inflammatory molecule) release, whereas Bute is nonselective for COX inhibitors; it inhibits all of them,” he says.
In a nutshell, it’s best not to inhibit all COX enzymes—some perform important gastrointestinal functions, and doing so could cause gastrointestinal upset. For more on this, see TheHorse.com/27043.)
Just as they can for other osteoarthritic conditions, chondroprotective (joint protective) agents such as glucosamine and chondroitin sulfate, which veterinarians and owners administer orally, can help improve affected horses’ comfort.
“Early on at the diagnosis of any arthritic condition, we’ll often prescribe these, and in some cases owners already have their horses on a supplement containing these substances for maintenance—especially older horses,” says Caston. “They may help with the health of other joints, as well, and for the horse’s comfort overall. But for a horse whose joint is fused, they won’t do anything to help that joint.”
Hyaluronic acid (HA), which veterinarians can administer intravenously or by intra-articular injection, is another chondroprotective supplement. “HA and corticosteroids are probably the most commonly used (injections) to treat these horses and help reduce inflammation in the joint,” Dryden says.
“HA is a building block of some of these components of the joint—cartilage and fluid—with some anti-inflammatory effects of its own,” says Caston. “Early on in the diagnosis, if we’re treating medically, we may combine corticosteroids (cortisone) with an HA product. It’s been shown to improve cartilage and joint health.”
Polysulfated glycosaminoglycan (PSGAG) is another medical treatment that can supplement your horse’s naturally occurring joint fluid and cartilage components. “PSGAGs that preserve the integrity of the joint are critical in managing ringbone,” says Dryden. “You can manage symptomatically with injections of HA and steroids, mainly to give the horse relief, but that doesn’t necessarily stop or prevent the disease process from occurring. There’s been virtually nothing that we’ve been able to do to completely halt the disease.
“I do think that in some cases, when you have some bone pain associated with ringbone, that bisphosphonates on the market can be helpful,” he adds. “They reduce osteoclast (bone breakdown) activity, and that essentially reduces bone remodeling. Additionally, these bisphosphonates have some analgesic effect for bone pain to keep these horses comfortable.”
One biologic Dryden says has merit is interleukin-1 receptor antagonist protein (IRAP). This is an anti-inflammatory therapy that blocks interleukin-1—one of the major inflammatory substances the body releases in the event of injury—from causing inflammation. “It’s helpful in treating some of these arthritic cases that are refractory (do not respond) to steroid treatment, so it’s another tool we have to help manage these cases from an intra-articular standpoint,” he says. “There’s another product on the market called Pro-Stride that I’ve used, which is a combination of PRP and IRAP. It’s an intra-articular injection that (in my experience) seems to have merit in some of these arthritic joints.
“Veterinarians are using PRP (platelet-reduced or -rich plasma) and stem cell therapies in these horses,” he continues. “I’d say there’s not enough literature out to say how well they work for severely arthritic joints, but I’d say it’s important to note that people are trying them.”
“IRAP, stem cells, and PRP can all be used, generally earlier on in treatment, in a joint that’s arthritic or injured,” says Caston. “They vary a little, but the goal for all three is to help reduce inflammation within the joint. PRP and stem cells have growth factors that help with repair. All come with different costs and, thus, may play into owners’ decisions on whether they’re going to choose those products.”
Can My Horse Continue Working?
Ringbone will affect your horse’s ability to work. Dryden says that on a scale of one to five in severity, horses can be managed and compete up to about a two. Beyond that, due to pain, the horse is not likely to compete at a high athletic level. Horses at a range of three to three-and-a-half can be very lightly used and from four to five are severely lame at a walk and unusable until the joint fuses fully.
Sometimes the horse’s body fuses the joint on its own (called ankylosis). Or, your veterinarian can fuse the joint in one of two ways. The preferred method is surgery to screw on a plate that stabilizes the joint. But if, for whatever reason, surgery is not recommended for your horse, your veterinarian can inject the joint with one of several substances that will degrade the cartilage and allow the horse’s body to finish the fusion process.
In her research, Caston monitored the success of injecting ringbone-affected pastern joints with alcohol rather than traditionally used but harsher chemicals with more side effects, especially if they get under the skin or leak out of the joint.
This injection method is less expensive than surgery, which is one reason owners choose it. Another is that some horses have other conditions, such as navicular disease or arthritis elsewhere, to manage at a cost that precludes surgery.
The good news is once the joint fuses, the horse can return to work. “That’s the goal, and that’s why this is such a special joint,” says Caston. “There are joints we fuse and the horse can become breeding-sound or pasture-sound, but with a pastern, because successfully fusing that joint doesn’t affect the motion of the limb, they can go back to full athletic ability.
“Owners and veterinarians often choose shoeing, medical treatments, and/or regenerative options prior to making the decision to pursue fusion of the joint because of cost and possible side effects and complications from either surgery or alcohol-facilitated ankylosis,” she continues. “With any procedure there are risks, and although the risk for complications may be low, if more conservative methods keep the horse comfortable and in work, then it makes sense to continue with those methods prior to pursuing surgery or facilitated ankylosis. When those treatments no longer keep the horse comfortable enough to be ridden or to be comfortable in pasture, then fusion of the joint is recommended.”
In the short term, ringbone can be painfully debilitating for your horse. However, once the pastern joint has fused, either on its own or with the help of surgery or injection, most horses can return to full activity. But this isn’t the case with the high-motion coffin joint. Even if you fuse it, says Caston, horses are usually only comfortable enough to be pasture sound.
In the meantime, a variety of treatments, from shoeing techniques to medical approaches to regenerative therapies, can help ease your horse’s pain.
Your treatment team—you, your farrier, and your veterinarian—can evaluate your horse’s unique situation and formulate a course of treatment that’s best for you both.