Osteochondritis Dissecans (OCD) in Horses
Updated February 28, 2025 | By: Jamie Whittenburg, DVM
Osteochondritis dissecans (OCD) is a type of orthopedic disease which occurs in the joints of horses and can lead to discomfort, lameness, and long-term performance issues. OCD is one of the most prevalent issues seen in young sport horses [1]. Though OCD is often referred to as a single disease, it falls under the broader category of Developmental Orthopedic Diseases (DOD), which also includes conditions such as angular limb deformities and subchondral bone cysts.
What is OCD in Horses?
Equine OCD results from abnormal cartilage development (the cushioning between joints). OCD lesions are formed when the normal process of cartilage turning into bone (endochondral ossification) is disrupted, leading to defects in the joint cartilage and underlying bone. These defects can result in cartilage flaps or bone fragments, which are diagnosable signs of the condition. OCD lesions often cause inflammation and pain. Areas that tend to be most affected include:
- Shoulders
- Fetlocks
- Stifles
- Hocks
This disease has been reported in people as well as other animals, such as dogs and pigs.
Understanding the Causes and Development of OCD
The exact cause of OCD in horses is unknown, but it is multifactorial, meaning it involves a combination of genetic, nutritional, and environmental influences. It is known that genetics and heritability play a role, and responsible breeding to avoid this condition is essential. Nutrition is another factor as rapid growth, excessive energy intake, and unbalanced calcium and phosphorus ratios are likely contributors to the disease. Also, high impact activities, such as running or jumping, can affect the cartilage of young horses, resulting in the formation of OCD.
Unfortunately, the OCD lesions themselves cannot provide information about the cause of the disease. Currently, two forms of OCD are thought to exist:
- A form in which the defect is inherent to the cartilage.
- An acquired form resulting from outside influences, such as nutrition and overexertion.
Potential Signs of OCD in Horses
In horses affected by OCD, early identification of OCD lesions is important and may improve treatment outcomes. Owners of young, developing horses should be particularly vigilant of their immature joints and growth plates. Things owners can watch for include:
- Lameness: Often intermittent and mild initially but becomes more noticeable over time.
- Joint Effusion: Swelling in and/or around the affected joint.
- Pain on Flexion: Increased discomfort when the joint is flexed.
- Reduced Performance: Reluctance to work or diminished athletic ability.
It is important to note that signs of OCD are often subtle, especially early in the course of the disease. Also, signs of trouble will vary depending on the joint affected. For instance, OCD in a horse’s stifle may cause more pronounced lameness than OCD in a fetlock.
How Veterinarians Diagnose OCD
If you see that your horse is lame or in pain, always consult your veterinarian as soon as you can. Veterinarians evaluate cases through a number of tools, like lameness exams and imaging modalities, to diagnose OCD. A basic work-up for a suspected OCD lesion in a horse will include a physical examination (including flexion tests, if appropriate) and radiographs (x-rays) to look for signs of a lesion. Advanced diagnostics, such as magnetic resonance imaging (MRI) and arthroscopy, may also be recommended.
Treatment Options for OCD
While OCD cannot be reversed, appropriate treatments may resolve clinical signs, improve joint health, and alleviate pain in affected horses. Conservative therapies are often initially implemented, and if the pain does not resolve, surgery may be required.
Non-surgical treatments
Options for conservative, non-surgical treatment include rest, time, and medications. Horses suffering with OCD lesions should rest and have a controlled exercise regimen prescribed by their veterinarian. Medications that may be used include non-steroidal anti-inflammatory drugs (NSAIDs) as well as hyaluronic acid and corticosteroid injections.
Surgical treatment
Many horses, especially those that are intended to be performance athletes, will require surgery for their OCD lesions. Arthroscopic surgery is the gold standard for removing OCD fragments and smoothing cartilage defects. Arthroscopy is minimally invasive and typically has a good prognosis for recovery.
During surgery, a small camera will be inserted into the affected joint to visualize the lesion. Simultaneously, small instruments will also be inserted into the joint to allow the surgeon to cut and scrape away the loose cartilage fragments. Arthroscopy to treat equine OCD will vary depending on the complexity of the surgery, but in general, owners should expect to pay between $5,000 to $10,000.
Post-surgery care must be taken to allow your horse to rest while they heal and then to slowly and progressively reintroduce exercise. A full return to your horse’s previous level of training and performance may take up to six months. Specific recommendations on aftercare will be made by your horse’s veterinary surgeon.
The prognosis for a horse affected with OCD to return to their previous athletic career is good to excellent with surgery, per the American College of Veterinary Surgeons [2].
Management Strategies for Horses with OCD
Once successfully treated, many horses with OCD can return to their full athletic abilities and can be ridden. Long term management will focus on keeping your horse’s joints healthy and may include routine examinations by their veterinarian, supplements for support, weight management, and consistent exercise.
Diet
Excess calorie intake is a key contributor to OCD in young horses. While it might seem beneficial to feed large amounts of grain to promote growth, a more balanced diet that encourages steady, controlled growth rather than accelerated weight gain will support skeletal health. Much like fulfilling dietary requirements and maintaining optimal body condition of your broodmare throughout gestation, the unique nutritional needs of a foal are essential to overall health and development. Your veterinarian and equine nutritionist are excellent resources to help you create a safe, comprehensive diet for your filly or colt.
Supplements That May Lend Support
Instead of increasing the amount of grain in your horse’s meals, talk to your veterinarian or equine nutritionist about adjusting your horse’s diet to include a properly balanced vitamin and mineral supplement, with consideration of the type of forage you’re feeding. A vitamin and mineral supplement could help provide essential nutrients without excessive calories, support normal development, and reduce the risk of nutritional imbalances.
Supporting joint, bone, and cartilage health
Owners should always consult with their veterinarian before feeding their horse a supplement. Key ingredients worth discussing with your veterinarian are listed below.
Naturally produced in the horse’s body:
- Glucosamine: Supports new cartilage production.
- Hyaluronic acid: An important component of articular cartilage for lubrication and shock absorption.
- Chondroitin sulfate: Stimulates hyaluronic acid production while inhibiting enzymes that break down cartilage.
Other ingredients:
- MSM (methylsulfonylmethane): May help address excess inflammation while protecting tissues from damage due to exercise or stress.
- Turmeric: With antioxidant properties, it may support comfort and a normal response to inflammation.
- Collagen: The main structural protein in bone, cartilage, tendons, and ligaments.
- Omega 3 Fatty Acids: Promotes cellular health and may help address inflammation.
- Magnesium: Plays numerous roles inside the body, such as enhancing calcium absorption and supporting bone health.
- Boron: Supports healthy bone growth and turnover.
- Copper: A deficiency or imbalance may contribute to OCD formation [3].
Preventing Orthopedic Disease in Young Horses
Strategies for preventing OCD in horses typically include:
- Responsible breeding.
- Balanced nutrition with appropriate levels of minerals.
- Avoiding overfeeding.
- Controlled exercise (especially in young and developing horses).
Key Takeaways
Osteochondritis dissecans is a complex condition that can affect performance, a horse’s quality of life, and be a financial burden for owners. Early diagnosis, appropriate treatment, and diligent management are key to minimizing its impact. With appropriate treatment, most horses affected with OCD will return to their previous level of athletic function.
If you are considering purchasing a horse with a history of OCD, it is essential to determine the location and severity of the lesion(s), how and when they were treated, and how the recovery has progressed. Thinking about the level of performance you hope for this horse to achieve is also important. To assess the current orthopedic condition of the horse, a thorough pre-purchase exam, including extensive x-rays, should be performed by your veterinarian.
Additional resources
- Guide to ingredients in horse joint supplements.
- Video on foal health 101.
Evidence-Based References
- L Martinez-Saez, PJ Marín-García, Lola Llobat. Osteochondrosis in horses: a review of non-genetic and genetic factors associated. Submitted to Equine Veterinary Journal. September 12, 2024.
- Osteochondritis Dissecans in Horses. https://www.acvs.org/large-animal/osteochondritis-dissecans-ocd-in-horses/
- Knight DA et al. The effects of copper supplementation on the prevalence of cartilage lesions in foals. Equine Vet J. 1990 Nov;22(6):426-32.