Osteoarthritis in Horses: Signs, Management & Nutritional Support

Osteoarthritis is the single most common cause of chronic lameness in horses. It affects leisure horses, competition horses, and veterans alike — and it is progressive. Here is what every horse owner needs to know about recognising it early, managing it well, and supporting joint health from the inside out.

If you've noticed your horse becoming reluctant to work, stiff after rest, or showing subtle changes in movement that your vet can't immediately explain — osteoarthritis may be the reason. It is estimated to affect up to 60% of lame horses in the UK, yet it remains widely misunderstood and frequently managed too late.

This guide is written for horse owners who want to understand what is actually happening inside their horse's joints, what the warning signs look like at every stage, and what nutritional support the evidence currently supports — alongside veterinary management.

What is equine osteoarthritis?

Osteoarthritis (OA) — sometimes called degenerative joint disease (DJD) — is a progressive condition characterised by the breakdown of articular cartilage within one or more joints. Cartilage is the smooth, protective tissue that covers the ends of bones where they meet in a joint. It acts as a shock absorber, allowing smooth, frictionless movement.

In a healthy joint, cartilage is continuously being broken down and rebuilt — a process driven largely by collagen synthesis. When this balance tips — through age, repeated mechanical stress, injury, or poor nutrition — breakdown begins to outpace rebuilding. The cartilage thins, becomes rough, and loses its ability to cushion the joint effectively. As it deteriorates, the underlying bone changes, inflammation becomes chronic, and joint fluid quality declines.

The result is pain, stiffness, reduced range of motion, and in advanced cases, significant lameness. Once cartilage is lost, it does not fully regenerate. This is why early identification and proactive management are so critical — the goal is to slow progression, reduce inflammation, and maintain as much cartilage integrity as possible for as long as possible.

It is worth noting that 30% of the equine body's total protein is collagen, and the joint itself is composed of up to 70% collagen. This makes collagen the single most structurally significant nutrient for joint health in horses — and the most logical place to focus nutritional support.

Which joints are most commonly affected?

Osteoarthritis can affect any synovial joint in the horse's body, but certain joints are more vulnerable due to the mechanical loads placed on them:

• Coffin joint (distal interphalangeal joint) — the most commonly affected joint, housed inside the hoof. Changes here can be difficult to detect without imaging.
• Fetlock joint — particularly in performance horses and those with conformational issues that increase load on the forelimbs.
• Hock joints — especially the lower hock joints (distal tarsal joints), commonly affected in warmbloods and sport horses. Low-grade hock OA is extremely common and often underdiagnosed.
• Stifle joint — increasingly recognised as a significant source of hind limb lameness, particularly in horses doing collected work.
• Pastern joint (proximal interphalangeal joint) — sometimes progresses to ringbone, a bony proliferation around the joint.

Recognising the signs — at every stage

One of the most challenging aspects of equine OA is that the early signs are subtle and easily attributed to other causes — hard ground, a bad day, ageing. By the time obvious lameness appears, significant cartilage damage has often already occurred. Knowing what to look for at each stage gives you the best chance of intervening early.

Stages of osteoarthritis — what is happening inside the joint

Risk factors — which horses are most vulnerable?

• Age — collagen production naturally slows with age, reducing the joint's ability to repair and maintain cartilage. Veterans over 15 are at significantly higher risk.
• High-intensity or repetitive work — racehorses, eventers, showjumpers, and dressage horses place significant repetitive load on specific joints over a career.
• Previous joint injury — horses that have sustained joint trauma, including chip fractures, ligament injuries, or synovitis, are at significantly higher risk of OA in the affected joint.
• Conformation — horses with conformational issues that create uneven load distribution across joints are predisposed to specific joint problems.
• Obesity — excess bodyweight places increased mechanical load on all joints, accelerating cartilage wear. Managing weight is one of the most impactful preventive measures available.
• Work surface — consistent work on hard, uneven, or inappropriate surfaces increases concussive load on joints significantly.

How collagen supports joint health in horses

Articular cartilage is made up of approximately 60–70% collagen by dry weight — predominantly Type II collagen, which provides the tissue with its unique combination of strength and flexibility. As collagen production declines through age, stress, or injury, the cartilage matrix weakens and the joint's ability to repair itself diminishes.

Hydrolysed collagen peptides — broken down into short amino acid chains — are absorbed through the gut and transported to target tissues including joint cartilage, where they act as biological signals to stimulate collagen synthesis in chondrocytes (cartilage cells). The research is clearest when tissue-specific peptides are used: specific peptide fractions have been shown to have preferential uptake in cartilage tissue, making targeted supplementation significantly more effective than generic hydrolysed collagen.

The NDS Equine approach to joint support

NDS Equine Nutrition holds a unique position in the UK market — as the only equine supplement brand offering a tissue-specific collagen series for horses. Rather than using a single undifferentiated collagen source, NDS formulates separate products for each tissue type, allowing targeted support for the specific area of concern.

For horses with joint concerns and osteoarthritis, the primary recommended product is NDS® Equine Ezy Move® — supported by the broader NDS Equine collagen range depending on the horse's individual needs.

How long before you see results?

Collagen supplementation works cumulatively, not acutely. Horse owners sometimes stop too early because results aren't immediate — understanding the realistic timeline is essential for staying the course.

Management beyond supplementation

Exercise management

Controlled, regular exercise is generally beneficial for OA horses — it maintains joint fluid circulation, muscle support around the joint, and cardiovascular health. Complete rest is rarely recommended unless there is acute inflammation. Work should be appropriate to the horse's level of comfort, on good surfaces, and with adequate warm-up and cool-down.

Weight management

Every kilogram of excess bodyweight places additional load on compromised joints. For overweight horses with OA, weight reduction is one of the single most impactful management steps available. Consult your vet or equine nutritionist for a safe weight loss plan.

Farriery

Regular, balanced farriery is critical for horses with joint disease. Therapeutic shoeing — including wedge pads, egg bar shoes, and specialist glue-on options — can significantly reduce pain and load on affected joints. Your vet and farrier should work together as part of your horse's management team.

Veterinary pain management

For horses with moderate to advanced OA, veterinary intervention is essential and should not be delayed or replaced by supplementation alone. Options include joint injections (corticosteroids, hyaluronic acid, PRP), systemic NSAIDs, and newer biologics. Supplementation works alongside these treatments — not instead of them.

Frequently asked questions