Researchers at Cornell University have identified key proteins in equine joint fluid that could improve the early diagnosis and treatment of osteoarthritis (OA) in equines.1 Arthritis is often associated with lameness in older horses. It can occur in any joint, and the disease often gets worse with age.

The researchers discovered that several proteins—including alpha-2-macroglobulin and pregnancy zone protein—”showed significant differences between healthy and arthritic joints.” 

Why Is This Important?

Cornell University noted that this finding is an important step in furthering osteoarthritis diagnosis and treatment.

“Most often OA is diagnosed based off clinical signs, then followed up with confirmation using radiographs,” said Dr. Erica J. Secor in a Cornell press release. “One of the problems with this approach is that the changes seen by radiograph happen late during OA development, once the lesions within the joint are irreversible. Our best chance of stopping or slowing the progression of OA would be very early in the process, before radiographic changes are present and clinical signs such as lameness are mild and intermittent. However, catching cases at this point is very difficult.”

The researchers noted that this study identified several differentially expressed synovial fluid proteins in equine carpal OA, many of which were previously unreported.

Take-Home Message

Research has shown that about 50% of horses older than 15 suffer from osteoarthritis. This prevalence grows to more than 80% for horses older than 30 due to normal wear and tear.

If veterinarians are able to identify early osteoarthritis, they can begin managing the horse earlier and perhaps slow or prevent progression.

While the protein identification method is not currently suitable for use in the field, further research could result in a stall-side diagnostic tool.

Reference

  1. Synovial fluid alpha-2-macroglobulin, gelsolin and lubricin distinguish between osteoarthritic and healthy equine joints. Erica J. Secor, Sydney J. Womack, Machiel P. Ysebaert, Marshall J. Colville, Heidi L. Reesink. Equine Veterinary Journal. May 2025.

Related Content

Sign up for My Senior Horse’s FREE newsletter to get the latest information about equids 15 years and older delivered straight to your inbox!   

  • Kimberly S. Brown and Jewell

    Kimberly S. Brown is an award-winning writer and publisher. She founded My Senior Horse for Equine Network and Linda Mars in her retirement, and now she is an editor of the brand. Brown previously had spent 10 years at Equine Network. Prior to that she worked for three years in equine nutrition after she retired from nearly 30 years working at The Blood-Horse. Brown spent the last 15 years of her time at that organization creating and developing the award-winning The Horse and TheHorse.com.

    View all posts