Horses put a great deal of strain on their joints. While even trail riding horses are made to carry a saddle and riders for hours at a time, even more is demanded of performance horses. These horses must run, jump, spin, pull carriages, or perform sliding stops from a full gallop.¹ Even horses that seldom go faster than a light trot with a rider aboard, this extra weight produces a great deal of wear and tear on joint structures in the long term.

As they age, almost all horses develop some joint inflammation and arthritic symptoms. These usually start with mild discomfort that can increase as the horse continues to exercise. Reducing the level of exercise, allowing the horse off time, reducing any extra  body weight and using pain-relieving medications can ease or eliminate discomfort for many horses. While these are suitable management options, they are not without shortcomings. Removing a horse from working “cold turkey” carries the danger of loss of body condition that can be hard to reverse, particularly in older horses.¹ Long-term use of NSAIDs (to relieve pain) can irritate the horse’s digestive tract, and masking pain through the use of these drugs can give human handlers the mistaken impression that the source of the horse’s discomfort is no longer present.^1-3

Joint Issues in Horses

Osteoarthritis (also called degenerative joint disease), is a progressive deterioration of the joint cartilage and the most common stress-related joint ailment in horses. This can come about as a result of long-term stress, or as a result of more serious joint conditions. Ultimately, osteoarthritis will produce lameness in the horse. Varying degrees of excess fluid may be present in the joint, as well as an abnormal thickening and scarring of the membranes and restricted motion of the joints. X-rays can show reduced joint space, bony protrusions, inflammation of the muscles and tendons, and a thickening of the tissue beneath the cartilage.¹

Bursitis is an inflammation of one or more of the fluid-filled sacs between tendons and  bones. These sacs (bursa) reduce friction around the joint. Bursitis is common in horses, and can range from mild inflammation to full-blown infection. “True bursitis involves inflammation of a natural bursa, for example, fistulous withers. In contrast, acquired bursitis is the development or inflammation of a bursa where none previously existed, as with capped elbow or hock.”² Bursitis can develop suddenly, with swelling, warmth, and pain (acute bursitis); chronic bursitis may persist over a protracted period of time with excess fluid and thickening of the affected areas. Chronic bursitis usually develops as a result of repeated trauma or other long term issues. Infective or septic bursitis is more serious and may produce pain and lameness in the joint.³ These infections are usually the result of bacteria directly penetrating into the bursa following an injection or injury.¹

Traumatic arthritis is usually associated with an injury, and includes inflammation of the synovial membrane (synovitis) and joint capsule (capsulitis), chip fractures within the joint, tears (sprains) of ligaments near or within a joint, or miniscus (cartilage within the stifle) tears.² Loss of cartilage of the joints over time can occur with any or all of these injuries. Traumatic arthritis may be seen in any horse, but typically occurs in performance horses.

Osteochondrosis presents with areas of immature joint cartilage separating from the underlying bone.² Fluid enters the spaces, and cysts may form under the cartilage. The cartilage may remain attached, or may break away from the bone. The exact cause of osteochondrosis is unknown, but contributing factors are thought to include genetic predisposition, rapid growth, a high intake of carbohydrates, mineral deficiencies or trauma (injury).

Septic Arthritis is typically caused by a bacterial infection in a joint. This may occur following an injury, surgery or injections, or it may enter the joint through the bloodstream. Such bloodborne infections are more common in foals.² Septic arthritis usually produces severe lameness and swelling of the joint; if fluid from the joint is obtained and examined, it will appear cloudy and contaminated.

Septic arthritis is extremely serious and must be treated immediately to avoid permanent joint damage. Infections are usually treated with injectable broad-spectrum antibiotics, as well as antibiotics injected directly in the joint. NSAIDs may also be prescribed.

Subchondral Cysts are cysts beneath the cartilage. These can occur in the femorotibial joint (stifle) and in the fetlock, pastern, elbow, shoulder, and distal phalanx (coffin bone) of horses.² Lameness is a common symptom. X-rays are necessary to confirm this diagnosis; usually, the veterinarian will assess the horse's lameness and may administer local anesthetic blocks. Surgery is usually recommended for cysts beneath the cartilage in the fetlock.

Treatment of Joint Issues

Horses that exhibit lameness, stiffness, or a lessened range of motion should be examined by a veterinarian who can determine the cause of the problem and prescribe the treatment that will be the most effective and least invasive. In many cases, a combination of therapies that work synergistically is most helpful in allowing horses to return work comfortably.

Methylsulfonylmethane, generally referred to as MSM, is a natural sulfur-containing compound found in the horse's body. It is also found in fruits, vegetables and fresh forage and grains. Horses use this supplemental sulfur primarily as a source of sulfur. It is important for healthy cartilage and antioxidant actions. In the horse's body, the compound splits into methionine and cysteine, two important amino acids. Supplementation with MSM in feed can aid in supporting joint health.²

Corticosteroids mimic the effects of hormones produced by the adrenal glands. Oral corticosteroids are typically used for horses with multiple joint problems or when the affected joint is not identified.³ When prescribed in levels higher than naturally found in the body, they suppress systemic inflammation. Injectable corticosteroids have a powerful anti-inflammatory action that halts destructive processes while relieving the horse’s pain.²

Injections made directly into the horse’s joints are helpful in some cases of joint inflammation. Hyaluronic acid (HA), a material naturally found in joints, can be injected to provide lubrication and reduce inflammation. Also known as sodium hyaluronate, hyaluronic acid binds to water to create a viscous, lubricating fluid. Found in connective tissue, cartilage and synovial fluid, HA can be injected directly into arthritic joints, administered as an intravenous injection or administered orally through feed supplements. HA has an anti-inflammatory effect and stimulates the production of more HA, which thickens the synovial fluid and increases its cushioning ability within the joint.²

Chondroitin is a major structural component of cartilage, bone, and connective tissues. The pain-relieving effects of chondroitin are not as pronounced as that of glucosamine, although it has been reported that horses given chondroitin seem to move with more fluidity.³ The greatest benefit of chondroitin appears to be in the prevention of further cartilage breakdown.

Glucosamine is a popular ingredient in joint supplements, and the most well-studied. It is available as glucosamine sulfate or glucosamine hydrochloride.³ Glucosamine is the basic building block of all connective tissues, including cartilage, and is manufactured in a pure form or isolated from sources high in glucosamine. Glucosamine is effective in relieving pain, sometimes in as short a time as 10 to 14 days.² Studies have shown that it can slow cartilage breakdown and may encourage the healing of injured joints.^1,3

Where to buy Hyaluronic Acid + Chondroitin + Glucosamine

 Hyaluronic Acid + Chondroitin + Glucosamine is available in the U.S. through veterinary custom compounding companies. HYALURONIC ACID 0.5% / CHONDROITIN 2.5% / GLUCOSAMINE 15% by NexGen Pharmaceuticals is an excellent formulation for the maintenance of joint health, as well as the treatment of strained or injured joints in the horse.

Please consult your veterinarian prior to beginning any treatment regimen.

FOR RX ONLY: A valid prescription from a licensed veterinarian is required for dispensing this medication.

¹Gibson KT, McIlwraith CW, Turner AS, et al. Open joint injuries in horses: 58 cases (1980-1986). Journal of the American Veterinary Medical Association. 1989 Feb;194(3):398-404.

²Brokken, M., et. al. Joint Disorders in Horses. (2017) In: J Vet Med The Ohio State University, 212-214. 

³Simmons EJ, Bertone AL, Weisbrode SE. Instability-induced osteoarthritis in the metacarpophalangeal joint of horses. American Journal of Veterinary Research. 1999 Jan;60(1):7-13.