Horse Side Vet Guide ®

Equine Health Resource

Osteoarthritis, OA, Generally

Synonyms: Chronic Arthritis, Degenerative Joint Disease, DJD

Osteoarthritis (degenerative joint disease) is the most common type of chronic arthritis that results from the ongoing breakdown of cartilage. Without cartilage, the bones are no longer cushioned against each other as they move and bear weight. Pain, stiffness and swelling results.

OA is very common, and is a significant cause of lameness in horses. Left untreated, cartilage damage and loss, pain, inflammation and dysfunction result in an ongoing cycle that eventually destroys the joint. It is the final consequence of any joint injury, whether due to infection or trauma and may result from chronic wear and tear.

Horses may develop this condition due to conformation or genetics, fractures, bone disease, or inflammatory conditions such as synovitis or capsulitis. Joints with poor conformation are more predisposed to developing chronic arthritis because of uneven loading and stress on the joint and support structures. Some low motion joints in the horse either fuse on their own eventually or can be intentionally fused. In some cases, this may be the only way to alleviate pain and restore function.

Prognosis & Relevant Factors

Poor to guarded. Depends on the joint involved and the degree of damage. Some joints in the horse are more tolerant of some degree of chronic arthritis than others. This disease can be career-limiting for some horses.


  • Why did this disease develop in this location?
  • Do you expect the disease process to progress despite treatment?
  • Are there direct treatments you recommend for individual joints?
  • What are your thoughts on the use of systemic medications for joints?

    Minimize the potential or severity of this disease by taking any joint injuries (wounds, swellings, pain) seriously and talk to your vet about your concerns. Select horses of good conformation, and ensure they are fit for the job. Keep your horse's hooves trimmed regularly and work them in proper footing.

    There are many injectable and oral supplements available, however you should talk to your vet before using these products. Unfortunately, many oral joint supplements are not supported by rigorous scientific evidence or do not contain the ingredients claimed.

    Helpful Outside ResourcesCredible Equine Health Information on the Internet

    Author: Doug Thal DVM Dipl. ABVP


    Koenig TJ1, Dart AJ, McIlwraith CW, et al. Treatment of experimentally induced osteoarthritis in horses using an intravenous combination of sodium pentosan polysulfate, N-acetyl glucosamine, and sodium hyaluronan. Vet Surg. 2014: 43(5):612-22.


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