When treating a fracture in a horse, the veterinarian must consider several factors before choosing conservative treatment over surgical intervention. While many fractures can heal with conservative management alone, it’s important to understand fracture types and the repair process so you can make informed decisions for each individual case.
Henry O’Neill, MVB, MS, DACVS, MRCVS, of Donnington Grove Veterinary Group, in Newbury, U.K., presented on this topic at the 2025 British Equine Veterinary Association Congress.
A Refresher in Bone Healing
Simplistically, bone undergoes four stages of healing: hematoma, soft callus, hard callus, and remodeling. Hematoma formation occurs immediately following fracture, followed by soft callus.
“The hematoma starts to undergo transformation, fibrocartilage begins to lay down between the bone ends, and we’re starting to get some rigidity imparted onto the fracture itself,” O’Neill explained.
After a few weeks, hard callus starts to form. “This is the process of endochondral fracture repair where the mineralization is really starting to lay down in that soft callus,” he said. “Over the following months and years, the final stage is a very slow remodeling process, which is ultimately taking the bone back to its original pre-fracture state.”
Fractures can heal in a couple of different ways, each dictated by the stability of the bone fragments. Ideally, you want primary healing.
“Primary healing occurs when the strain, or essentially the movement of those fracture fragments, is minimal, or less than 2%,” which generates minimal callus, said O’Neill.
When there’s a little more movement in the fracture margins—2-10% strain—then the next stage is secondary endochondral healing. These injuries will still heal; the process just won’t be as efficient as the primary mode of healing, he noted.
With excessive movement of the fracture fragments (strain > 10%), the injury enters a stage of nonunion. In these cases, movement exceeds the bone’s capacity to form a bridging bony callus between the ends of the fragments, said O’Neill.
When Might Conservative Management Be Indicated?
Several factors will affect your decision to pursue conservative management. “It really comes down to fracture configuration,” O’Neill said. Incomplete, nondisplaced, and stress fractures are ideally suited for management with stall rest.
Fracture location is also important. Some fractures, such as lumbar and many pedal bone fractures, are simply located in areas where veterinarians can’t manage or access for surgery. With articular involvement, you can manage the fracture if it’s incomplete and the joint surface remains congruent, with no movement, he said.
Consider patient factors, such as age, temperament, and intended use. “Foals are such good patients to work on in regard to fractures,” said O’Neill. “Foals have a great capacity to heal in a quick manner.”
The patient should be able to handle prolonged periods of stall rest, and the owner should not have expectations for the horse to return to performance quickly.
Finally, financial and logistical limitations (e.g., is the horse beyond the reach of a surgical facility?) factor into the decision-making process.
Complications and Risk Mitigation
O’Neill then listed possible complications veterinarians might encounter with conservative fracture management:
- Slow or nonhealing fractures. “It comes down to movement and stability,” he explained. “Sometimes the body simply cannot overcome and bridge that callus over the top of the bone.”
- Sores associated with long-term bandage and cast application. He urged veterinarians to not underestimate these, as the healing time for bad sores can take longer than the injury itself.
- Support-limb laminitis, which you can help prevent with orthotic support.
O’Neill reminded veterinarians that horses are particularly vulnerable in the first few weeks after injury. During this stage, the fracture can propagate into a much more complicated and comminuted arrangement.
Owner skill and compliance can also be an issue. “Sometimes they just don’t have the ability to recognize when things are going wrong,” he said.
Summary
Conservative management can be appropriate for certain fractures. Consider the multiple factors in play when trying to make this decision. And never feel embarrassed to ask for a specialist’s advice.
“It’s our job as surgeons to be the knowledge and resources for these,” said O’Neill. “If you’re unsure about going the conservative route, don’t be afraid to ask.”
Related Reading
- Daily Vet Life: Standing Fractured Splint Bone Removal
- Equine Rib Fractures as Cause of Poor Performance
- Pelvic Bone Stress and Fatigue Fractures in Endurance Horses
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