Osteochondrosis in young horses: what you need to know

What exactly is osteochondrosis?

During growth, cartilage is gradually converted into bone. In osteochondrosis, this process does not proceed evenly: certain zones of the cartilage receive insufficient blood supply and die off. The result is weak, unstable tissue that can break down under pressure. When OCD (osteochondrosis dissecans) is diagnosed, a loose fragment of cartilage or bone is already present within the joint. OC affects primarily fast-growing, large breeds such as KWPN horses, warmbloods, and trotters. The most commonly affected joints are the hock (tarsus), the stifle, and the fetlock or knee joint.

Risk factors you can influence

OC has both a genetic component and environmental factors. Heredity plays a role, but nutrition and exercise are at least as important — and as an owner, you can directly manage those.

• Growing too fast due to overfeeding with energy and protein in the first months of life
• Unbalanced mineral ratios: in particular too little copper and zinc relative to calcium
• Excessive concentrate feed for foals younger than six months
• Irregular exercise: prolonged stable rest alternating with sudden peak loads
• Breeding for extremes in conformation and early maturity

Recognise early signs in time

OC does not always cause immediate pain. Nevertheless, there are subtle indicators you can pick up early if you pay close attention to your foal or young horse.

• Joint bulging or swelling, often without warmth or pain on palpation
• Mild lameness that disappears after rest but returns with more exercise
• Stiffness and reluctance when picking up a leg or flexing a joint
• Falling behind in training or inability to work as hard as peers
• Visible asymmetry in leg stance in the foal

Diagnosis: X-ray and ultrasound

A vet establishes the diagnosis based on clinical examination supplemented with imaging. X-rays reveal bone defects and loose fragments, while ultrasound visualises soft tissue. If there is doubt, a joint puncture is sometimes performed to confirm increased fluid. It is advisable to have KWPN foals undergo a standard radiological examination at around four to six months of age: abnormalities are already visible at that stage but the chance of spontaneous recovery is still greatest. Record all findings, images, and veterinary reports in your horse's EquiSight horse profile, so you have a complete timeline for follow-up consultations.

Treatment options: rest or surgery?

Not every OC case requires surgery. The choice depends on the location, the severity of the lesion, and the intended use of the horse. Small lesions in less loaded areas can heal spontaneously with targeted movement restriction and dietary correction, provided they are discovered early. Larger or loose fragments — classic OCD — are surgically removed via arthroscopy. This is a minimally invasive procedure in which the surgeon removes the fragments from the joint through small incisions. The recovery period is typically three to six months, depending on the joint and the extent of the lesion. Horses that have been successfully operated on can go on to build a full sporting career in more than 70% of cases.

Nutrition and exercise as prevention

You can significantly reduce the risk of OC by consciously managing your foal's growth. A few practical guidelines:

• Feed the mare and foal a well-balanced foal feed with sufficient copper (minimum 25 mg/kg dry matter) and zinc
• Limit energy-rich supplementary feed in the first six months of life; aim for steady, not too rapid growth
• Ensure daily free exercise in a spacious paddock — this promotes healthy joint development
• Avoid sudden changes from stable to pasture periods without gradual acclimatisation
• Have mineral status checked annually through blood tests, especially on peat soils with copper-poor ground

EquiCoach helps recognise patterns

Small changes in behaviour or movement can sometimes be difficult to interpret, especially if you have several horses. EquiCoach in EquiSight analyses the notes and observations you keep in your horse profile and helps you draw connections you might otherwise miss. Ask questions such as 'Has the slight lameness in the right leg been present for a while?' or 'When did the vet last examine the joints?' — EquiCoach gives you an instant overview based on your own records. That way you stay in control, even when it comes to subtle health signals in young horses.