What Is Osteoarthritis in Horses?

Osteoarthritis (OA) is also known as degenerative joint disease (DJD). It is not always clinically progressive, although it might be in some cases (especially if abnormal conformation is a predisposing factor). It is characterized by joint inflammation.¹ This can lead to pain, swelling, and reduced range of motion.² It occurs frequently in older equines, but can occur in young horses as well.

Researchers have found that osteoarthritis is the most common cause of lameness in horses. One survey found that about 60% of lameness problems in horses were associated with OA.³

What Causes Osteoarthritis in Horses?

In horses, osteoarthritis can be triggered by a variety of factors. These include age, years of athletic use, and injury to articular cartilage, synovial membrane, subchondral bone, ligaments, or the fibrous joint capsule.

Equine osteoarthritis can develop from consistent wear and tear on the joints over time. This is especially true in cases where the animal engages in frequent, high-impact activities. Such repetitive stress can eventually lead to the deterioration of cartilage.

Osteoarthritis can also be precipitated by acute injury, such as a joint fracture or a torn ligament. This can result in joint instability and accelerated joint damage, even after the initial injury has healed.

There are several factors that might contribute to the development of OA in horses, including:

Age. As horses age, their cartilage becomes less resilient and more prone to damage.
Genetics. Certain breeds might have a predisposition to developing OA due to inherited bone structure or body conformation.
Diet and nutrition. A diet high in sugar or low in essential nutrients can weaken cartilage and make it more susceptible to damage.
Conformational issues. Horses with conformational abnormalities, such as poor limb alignment, might put uneven pressure on their joints, leading to joint degeneration over time.
Overloading of joints. Excessive weight or overuse from strenuous activities can put excessive strain on joints and contribute to cartilage damage.
Past injuries. Previous joint injuries or surgeries can increase the risk of developing OA in a specific area.

Clinical Signs of Osteoarthritis in Horses

The clinical signs of osteoarthritis in horses might vary depending on the severity, location, and progression of the disease. Some common signs include:

joint pain and stiffness
lameness or difficulty walking
swelling and heat in the affected joints
reduced range of motion
crepitus, which is a grinding or cracking sound coming from the joint during movement

Diagnosing Osteoarthritis in Horses

If you suspect that your horse might be suffering from osteoarthritis, a veterinarian can perform a thorough physical examination. She or he might recommend additional diagnostic tests such as:

X-rays. Radiographs can help visualize the joint damage and changes in cartilage.
Joint fluid analysis. A sample of synovial fluid from the affected joint can be examined for signs of inflammation and degeneration.
Ultrasound or MRI. These imaging techniques can provide a more detailed view of the joint and surrounding tissues.

Treatment Options for Osteoarthritis in Horses

Unfortunately, there is no cure for osteoarthritis in horses. However, various treatment options might help manage clinical signs and slow the progression of the disease. Treatments include:

Non-steroidal anti-inflammatory drugs (NSAIDs). These medications can relieve pain and reduce inflammation in the affected joint.
Injectable medications. In some cases, veterinarians might recommend injecting medication directly into the joint to provide localized relief. These might include corticosteroids, hyaluronic acid, or platelet-rich plasma (PRP).
Joint supplements. Supplements containing ingredients such as glucosamine and chondroitin sulfate can help support joint health.
Physical therapy. Controlled exercise, massage, stretching, and hydrotherapy can help improve joint mobility and reduce pain.
Surgery. In severe cases or advanced stages of OA, surgery might be necessary to remove damaged tissue or fuse the joint.

Final Words

As we consider the multifaceted approach required to manage osteoarthritis in horses, it becomes clear that proactive measures and timely interventions are crucial for our animals’ well-being.

While the underlying causes of osteoarthritis in horses can vary, certain conditions and activities enhance susceptibility to the disease. Factors such as excessive workload on the joints, especially in competitive sports, can accelerate cartilage wear. Conformational issues, where the alignment of a horse’s legs and hooves is less than ideal, can lead to uneven stress on joints, predisposing them to OA.

Age is a significant factor as older horses are more likely to develop the condition due to the natural degeneration of joint tissues over time.⁴ Genetics also play a role, with some breeds showing a higher propensity for joint problems.

Understanding these factors is key to both preventing and managing OA in horses effectively.