KBR Horse Health Information

Care AND Prevention

Managing Arthritis in Horses

Horses are athletic animals, oftentimes confined for long hours then exercised hard. Such activity cycles, along with accidents and other trauma, can lead to joint inflammation and loss of movement. This pathology often takes the form of osteoarthritis

"Prints" was diagnosed as being incurably
unsound about 10 years prior to this photo
of him performing in The Music Man

Osteoarthritis is basically the breakdown of the cartilage which lines the bones that make up a joint. Cartilage can be worn down to the point that actual bone material rubs together. In some cases cartilage fragments break off which can irritate adjacent muscles. As the joint wears and becomes distorted, pain can occur in the muscles that support and generate movement in the joint.

Fortunately cartilage is a material that under proper conditions can stabilize itself to some degree. If some corrective remodeling of the tissues can be encouraged and "wear and tear" to the joint is reduced, some long term restoration of joint function and reduction of pain can be achieved.

While there are a number of products and preparations for sale for the treatment of arthritis in horses, we have had good results with the following medications and supplements when combined with controlled therapeutic exercise.


Glucosomine sulfate and chondroitin sulfate are both "over the counter" supplements that can be added to the horse's daily ration. Recent studies in Toronto have shown that Glucosomine Sulfate in particular has resulted in improvement of arthritic joints in clinical studies.

Chondroitin is a natural component of joint cartilage and chondroitin sulfate is believed to block certain enzymes that tend to break down cartilage. While experts disagree on how much chondroitin is actually absorbed when taken orally, preliminary findings suggest that chondroitin supplements are linked to the stabilization and sometimes the functional restoration of certain arthritic joints.

Based on our experience with older arthritic horses, we prefer supplements that combine glucosomine sulfate and chondroitin sulfate.

(hyaluronate sodium)

The most remarkable results we have experienced involved the intravenous application of "Legend" injectable solution. Available by prescription, Legend hyaluronate sodium readily converts to hyaluronic acid in the joint. High concentrations of hyaluronic acid are found in synovial fluid, the lubricating liquid of joints. Hyaluronic acid exerts an anti-inflammatory action in the joint. It also appears to regulate normal cellular constituents in a way that decreases enzyme release and degradation of joint integrity. It has no known significant side effects and virtually all of the horses we witnessed that had even relatively advanced arthritis in stable joints showed visible improvement after receiving a series of injections.

Hyaluronic acid is found in certain microorganisms. In Legend, hyaluronic acid is extracted from Streptoccus spp. and is purified to a form that is free of protein and nucleic acids. Since Legend originates from a microbial source, there is no potential for contamination with dermatin, chondroitin sulfate or any other glycosaminoglycan.

In layman's terms Legend is safe to use in conjunction with oral supplements and there are no contraindications listed on the Legend package insert.

Legend is a registered trademark of Bayer Corporation


Bayer: Equine Joint Disease Therapy

FDA Clinical Trial


We observed a small number of older arthritic horses, one of which was our own. These animals were suffering from advancing arthritis that had caused sufficient joint degeneration to make the horses unfit for riding. These horses had reached the point where oral supplements were no longer maintaining adequate joint function.

Legend's label recommends that dosages be given at weekly intervals. In these horses we chose to administer Legend injectable on a monthly basis. In most instances the horses started showing signs of improvement within two weeks. By the third month these horses were showing significant improvement and returned to light work. One older mare with an unstable joint did not improve, however in her case the joint damage was significant prior to administering the series of injections.

These horses continued to receive oral supplements of glucosomine sulfate and chondroitin sulfate during the injection series and continuously thereafter. Most of the horses needed a Legend "booster" about 18 months following the initial series.


These animals seemed to also benefit from regular controlled exercise. Regular low impact joint movement, such as being turned out to amble and graze, appeared to aid in the reduction of pain and recovery of resistance free joint movement. Overexercise could still result in pain and inflammation, but those instances appeared to be less problematic than before treatment was provided.

As with any orthopedic situation, horses can benefit from certain medications, but common sense and practical use of recovering horses is, in our opinion, equally important.


What we have learned so far is:

  • Practical preventive care (not overstressing the joints, particularly in young horses) is the most efficient and cost-effective way to avoid osteoarthritis problems.

  • As the horse ages and arthritic changes start to develop, oral supplements appear to help control arthritic decline.

  • As osteoarthritis advances, Legend injectable given in a series can oftentimes produce visible beneficial results.

  • In all cases, sensible exercise and avoiding situations that generated significant stress in arthritic joints appeared to help the condition of these horses.
In addition, it's always a good idea to radiograph any arthritic joint prior to treatment in order to be sure that the joint is stable (not fractured or subluxated) and to provide a baseline that can be compared with radiographs that are taken later when the horse's condition changes.

As with any prescription medication, the subject horse should be properly diagnosed by a veterinarian before starting therapy using Legend injectable solution. In addition to its osteoarthritic condition, the whole horse, including balance of foot, environment, exercise and diet should be considered in order to produce a rehabilitation program that maximizes the horse's favorable response to the medication being used, and to prolong the horse's comfort and usefulness if its osteoarthritis pain and lameness are to be successfully managed.
Ponying a young mustang
through the obstacle course

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KBR Horse Health Information, 1997 Lamm's Kickin' Back Ranch and Willis & Sharon Lamm. All rights reserved. Duplication of any of this material for commercial use is prohibited without express written permission. This prohibition is not intended to extend to personal non-commercial use, including sharing with others for safety and learning purposes, provided this copyright notice is attached.
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