GLUCOSAMINE, CHONDROITIN SULFATE, HYALURONIC ACID, AND MSM AS THE FOUNDATION OF JOINT HEALTH
Joints are a constant topic of discussion in the horse world—and for good reason. Healthy, resilient joints are essential for every horse. A horse’s joints are under significant stress simply from supporting the animal’s own body weight—hundreds of kilograms carried by relatively slender limbs. When the weight of a rider or cart and intensive training are added, the strain can lead to damage. Small injuries may be subtle and go unnoticed initially, only becoming apparent later if the stress continues and damage progresses. One of the most common reasons for veterinary visits is lameness, most often related to joint inflammation and the resulting joint degeneration, or osteoarthritis.
Bones and joints continue to develop throughout a horse’s adult life. Stress on the joints is not always harmful—some degree of loading is necessary to increase strength, resilience, and durability. The body requires stress in order to adapt and become stronger. For this reason, training intensity should be increased gradually. Problems can arise if a horse is trained too intensely, worked on poor footing, or does not receive sufficient nutrients to support joint health. Major risk factors include aging, excess body weight, joint injuries, and excessive physical workload. Genetic factors also play a significant role.
CROSS-SECTION OF A JOINT
Let’s briefly review joint anatomy to better understand what happens inside the joint during injury.
Equine joints connect two or more bones and allow them to move relative to one another. The joint is held together by a joint capsule, whose thin inner lining is called the synovial membrane. The synovial membrane secretes synovial fluid, which lubricates the joint. Synovial fluid allows bones to move smoothly without contacting each other, preventing wear of the joint surfaces.
These structures are enclosed within the joint capsule and supported by ligaments. The ends of the bones are covered by a smooth layer of articular cartilage, composed of specialized cartilage cells that produce large amounts of extracellular matrix. Cartilage is a critical component of the musculoskeletal system, as it absorbs the high pressures placed on bone ends and prevents wear in a healthy joint. Cartilage is also the structure most susceptible to joint damage.
For example, when a horse lands on its forelimbs after a jump, significant force is applied to the joints as they absorb the impact. This compresses the cartilage, causing very small micro-damage that typically heals on its own. Problems arise when joints are repeatedly subjected to excessive stress. In such cases, the horse’s natural defense systems cannot produce sufficient nutrients required for joint repair and maintenance. Cartilage degeneration then triggers a chain reaction leading to inflammation, stiffness, lameness, and pain. Chronic joint inflammation can ultimately result in osteoarthritis. While the underlying cause of osteoarthritis is not fully understood and no cure exists, symptoms can be significantly alleviated.
TREATING JOINT DISEASE – NUTRITIONAL SUPPORT
Joint inflammation and osteoarthritis are most commonly treated by veterinarians with intra-articular injections, often corticosteroids. Additional support may be provided through oral complementary feeds, which can be used both preventively and to support existing joint issues and maintain joint function. Because cartilage health is essential for mobility and overall well-being, it deserves careful attention in feeding strategies.
Adequate nutrition is especially important for foals and young horses to ensure proper growth and development. Nutrition remains important throughout the horse’s life, particularly as the horse ages or workload increases.
Certain nutrients can support synovial fluid production, maintain normal joint function and mobility, and reduce degenerative changes in bone.
The most important joint-supporting nutrients naturally found in the body are glucosamine and chondroitin sulfate.
COMPLEMENTARY FEEDS FOR JOINT HEALTH
Glucosamine is a naturally occurring compound in joint cartilage, and its levels decrease with age and in osteoarthritis. Glucosamine acts as a joint lubricant, supporting joint health, function, and mobility. It helps maintain synovial fluid viscosity and elasticity, preventing it from becoming thin and watery. Glucosamine is also a key building block for other joint-supporting compounds and plays a role in regulating cartilage growth and repair. While glucosamine is naturally present in the body, studies show that circulating glucosamine from dietary sources can be utilized when requirements increase. Long-term supplementation (three to six months) is recommended for horses subjected to increased joint stress, both for prevention and rehabilitation, to evaluate individual benefit.
Chondroitin sulfate is essential for normal cartilage health. Research suggests it may reduce inflammation and inhibit enzymes that degrade cartilage, while also stimulating cartilage regeneration.
In osteoarthritis, chondroitin sulfate levels in cartilage decrease early in the disease process. Although it cannot cure osteoarthritis, it may alleviate symptoms, slow disease progression, and support cartilage-building processes. Chondroitin sulfate also increases hyaluronic acid production in joints, improving synovial fluid viscosity.
Hyaluronan, or hyaluronic acid, is found throughout the body in the extracellular space and is a key structural component of cartilage. It is particularly important in rapidly growing, renewing, and healing tissues. Hyaluronic acid functions as a shock absorber, elasticity maintainer, and lubricant in joints and other tissues, and it may influence how the body responds to tissue damage.
MSM is an organic sulfur compound naturally present in the body. Sulfur is an essential component of many bodily compounds and functions. It supports cell membrane flexibility and permeability, facilitating nutrient and waste transport. Sulfur also provides raw material for new cell formation and tissue repair and renewal. It is required for connective tissue and collagen synthesis. MSM is best known as a nutrient supporting connective tissues such as joints, bones, hair, and hooves. Sulfur is also found in rosehip seeds.
These ingredients are among the most common and extensively researched compounds supporting joint health. Many others are discussed in more detail in the joint section of our website.
When adding joint-supporting compounds to the diet, it is important to remember that they work best over time—results are not immediate. This does not mean supplementation must continue for the horse’s entire life, but regular, moderate use—such as throughout the competition season—is more effective than short-term use immediately before heavy exertion.
