Ringbone is a degenerative arthritic condition in horses where new bone grows around the pastern or coffin joints in the lower leg. It affects horses of all breeds, ages, and disciplines, and it’s one of the more common causes of chronic lameness in the front limbs. The condition comes in two main types depending on which joint is involved, and its long-term outlook varies significantly based on location and how early it’s caught.
High Ringbone vs. Low Ringbone
The two types are defined by which joint they affect. High ringbone involves the pastern joint, which sits between the two small bones in the lower leg above the hoof. Low ringbone affects the coffin joint, located where the lower pastern bone meets the coffin bone inside the hoof itself. Both types involve the gradual buildup of extra bone around the joint, but low ringbone is generally harder to detect early because it’s hidden inside the hoof capsule.
There’s also a distinction between articular and non-articular ringbone. Articular ringbone involves the joint surface directly, meaning the new bone growth affects where the bones meet and move against each other. Non-articular ringbone, which is less common, involves bone production around the perimeter of the joint without initially invading the joint surface itself. The articular form tends to cause more significant lameness because it directly disrupts the smooth cartilage that allows the joint to flex.
What Makes Ringbone Different From Other Arthritis
Most types of osteoarthritis in horses start with bony growths right at the edges of the joint cartilage. Ringbone works differently. The initial bone deposits typically form outside the joint itself, and only later do they spread to involve the cartilage margins. As these extra bone deposits build up above and below the joint, they interlock like a series of plugs and sockets. This mechanical interference is what reduces the joint’s range of motion over time. Many people assume the joint is fusing into a solid mass, but in most cases the stiffness comes from these interlocking bone spurs physically blocking normal movement rather than true fusion.
Causes and Risk Factors
Ringbone develops from a combination of conformation, workload, and injury. Horses with very upright pasterns face higher risk because the steep angle concentrates impact forces on the joints rather than dispersing them through the natural shock-absorbing flex of the pastern. Limb deviations also contribute: horses whose legs angle outward or inward from the midline place uneven pressure on one side of the joint, gradually wearing down the cartilage asymmetrically.
The most common triggers, though, are working on hard surfaces from a young age and direct injuries to the joint’s cartilage or supporting ligaments. A single traumatic event, like a bad step or a kick, can damage cartilage enough to set the degenerative process in motion. Repeated concussion on hard ground does the same thing over months and years. Excess body weight doesn’t necessarily cause ringbone on its own, but it accelerates the damage once the process has started.
Early Signs and Symptoms
Ringbone typically starts subtly. The earliest sign is usually a mild, intermittent lameness that may come and go depending on the horse’s workload. You might notice the horse landing unevenly, shortening its stride, or becoming reluctant to work on firm ground. The lameness tends to be worse when the horse first starts moving and may improve slightly as the joints warm up, though this pattern isn’t always reliable.
As the condition progresses, you may feel warmth or slight swelling around the pastern area. With high ringbone, a firm, bony ridge eventually becomes visible and palpable across the front and sides of the pastern. Low ringbone is trickier because the hoof wall hides the changes. In either case, lameness worsens progressively if the horse continues working without changes to management. By the time bony enlargement is obvious to the eye, the disease has usually been developing for some time. Veterinarians confirm the diagnosis with X-rays, which reveal the characteristic new bone growth around the affected joint.
How Ringbone Is Managed
There’s no cure for ringbone. The extra bone growth can’t be reversed. Management focuses on slowing the progression, controlling pain, and keeping the horse as comfortable and functional as possible.
Anti-Inflammatory Medication
Anti-inflammatory drugs are the most accessible and cost-effective tools for managing ringbone pain. The workhorse of equine pain management is phenylbutazone (commonly called “bute”), which is the most widely prescribed anti-inflammatory for orthopedic pain in horses across the U.S., U.K., and Canada. There are also newer, more targeted options that specifically address inflammation-related pain while potentially causing fewer side effects with long-term use. Your veterinarian may also recommend joint injections to deliver medication directly into the affected joint, which can provide longer-lasting relief than oral drugs alone.
Corrective Shoeing
Farrier work plays a major role in ringbone management. The goal is to reduce the mechanical stress on the affected joint with every step. This often means modifications like a rolled or rockered toe, which makes it easier for the horse to break over (the moment the hoof lifts off the ground mid-stride) without forcing the pastern or coffin joint to flex as far. Pads, bar shoes, or adjustments to the hoof angle can also redistribute weight and reduce impact. The specifics depend on which joint is affected and the horse’s individual conformation, so close collaboration between your vet and farrier matters.
Workload and Surface Changes
Reducing concussion is essential. Switching to softer footing for turnout and exercise, lowering the intensity of work, and avoiding hard or rocky ground all help slow the progression. Some horses with mild ringbone can continue in lighter work for years with these adjustments. Others, particularly those with low ringbone affecting the coffin joint, may need to be retired from ridden work entirely.
When Surgery Is Considered
For high ringbone that doesn’t respond adequately to conservative management, surgical fusion of the pastern joint is an option. The procedure, called arthrodesis, deliberately fuses the two bones of the pastern into a single unit, eliminating the painful bone-on-bone movement. This sounds drastic, but the pastern joint has a relatively limited range of motion compared to higher joints, so many horses adapt well.
A meta-analysis of retrospective studies found a 90% survival rate following pastern fusion surgery, meaning the vast majority of horses recover from the procedure itself without life-threatening complications. About 65% of horses returned to their intended activities afterward. Hospitalization averaged around 25 days, with a cast typically staying on for about 29 days. Surgical site infection occurred in roughly 12% of cases. These numbers are encouraging but also highlight that a third of horses don’t return to full function even after surgery, so it’s not a guaranteed fix.
Surgical fusion is primarily an option for high ringbone. The coffin joint involved in low ringbone bears far more of the horse’s weight and has a greater role in locomotion, making fusion of that joint much less practical and carrying a worse prognosis.
Long-Term Outlook
The prognosis depends heavily on which joint is affected and how early the condition is caught. High ringbone generally carries a better outlook than low ringbone, partly because the pastern joint contributes less to overall movement and partly because surgical fusion is a viable option when conservative care fails. Horses with mild high ringbone caught early can sometimes perform comfortably for years with proper shoeing, medication, and workload adjustments.
Low ringbone is more challenging. The coffin joint is critical to how the horse moves, and it’s harder to manage both medically and surgically. Horses with significant low ringbone often face earlier retirement from performance work, though many live comfortably as pasture companions with appropriate pain management. In all cases, ringbone is a progressive condition. The extra bone won’t shrink or disappear, and the underlying joint damage continues over time. The realistic goal isn’t to fix the problem but to manage it well enough that the horse stays comfortable and maintains whatever level of activity its joints can handle.