OCD lesions are cartilage flaps (sometimes containing bone) that develop at the end of bones near joints during a young horse‚Äôs development. This condition is most common in young horses that experience rapid growth spurts.
The Cause of OCD Lesions
There is still much to be learned about OCD lesions. A major mitigating factor is nutritional or mineral imbalance in the horse‚Äôs diet, such as a diet high in carbohydrates or protein, which results in rapid growth in the first year of life. There are a variety of other reasons a young horse will develop OCD lesions, such as trauma to a joint, higher than average body weight, and hereditary reasons.
OCD lesions are most commonly found in stifle, hock, and fetlock joints as well as between neck vertebrae. Although less common, lesions can also occur in the shoulder, hip, and elbow joints.
OCD lesions will generally develop within the first 11 months of life but may not be noticed until 3 to 5 years of age as the horse begins training. If you are considering the purchase of a young horse, it is a good idea to radiograph those joints that are most affected to determine if OCD lesions are present.
The Process of OCD Lesions
As the soft cartilage cells at the end of bone turn into bone cells and lengthen the bone, sometimes the process goes askew and the cartilage pulls away from the bone. This process results in OCD lesions. These flaps can also break loose and find their way into the joint, also known as ‚Äújoint mice.‚Äù
The Effect of OCD Lesions
The lesions cause inflammation and fluid buildup resulting in varied levels of lameness. Over time, if the condition is left untreated, the affected joints can develop degenerative joint disease, also known as arthritis.
Q&A with Dr. Hartman
Q: Do OCD lesions have to be surgically removed?
A: OCD lesions in horses older than 15 months old should be removed. Generally, we do not recommend surgery in horses any younger than 15 months old. It is possible that lesions in these foals will resolve themselves.
Q: What percentage of horses goes back to full work after surgery?
A: In my experience, the success rate is around 85% percent.
Q: Are regenerative medicines, such as stem cell therapy, viable treatment options?
A: Generally, growth in the damaged area has stopped so we are uncertain at this time if stem cell therapy is a successful treatment option.
Q: Can joint injections be used to treat OCD lesion?
A: You can treat OCD lesions with injections but you are just masking signs. By masking the pain or swelling, you increase the risk of further injury.
Q: How does a surgeon treat an OCD lesion?
A: A surgeon will remove the lesion, scrape away any underlying defective bone or tissue, and then flush the joint to ensure removal of any lingering fragments.
A secondary method that involves pinning the flap down also has promise. The benefit of this method may produce a more stable joint in the long term. However, OCD lesions that are irregularly shaped are not good candidates for this method.
Q: Can you prevent a foal from developing lesions?
A: If a young horse is experiencing OCD but has not yet developed lesions, treatment may consist of changing its diet to slow rapid growth.
Q: If my horse was previously treated for an OCD lesion, is he likely to suffer from it in other joints?
A: Recurrence is not a common problem in the same joint. It is more common to find lesions in the corresponding joint on the opposite limb.
Q: How do these lesions cause pain?
A: Lesions expose interior bone, releasing debris into the joint and resulting in inflammation.
Q: What are the clinical signs of OCD lesions?
A: Joint swelling and lameness are the most common signs.