Joint problems OC and OCD: What is it and what can you do about it?

OC and OCD are joint abnormalities in horses. Both conditions often arise during rearing and relatively many horses are affected by them. What is the difference between OC and OCD? Are these abnormalities always serious? And can something be done about them?

Osteochondrosis (OC) and Osteochondrosis Dissecans (OCD) are well-known joint disorders in horses. As a young horse grows up, part of its cartilage calcifies and becomes bone. If this growth process is disrupted, OC and/or OCD can develop.

The difference between OC and OCD

With OC and OCD, there is a disturbance in the calcification process from cartilage to bone. In OC, this disturbance causes 'flattening' on the joints. The bones of a joint are then no longer optimally shaped and do not fit perfectly together. This can cause movement problems, especially later in life. Sometimes, cracks can also be seen on the X-rays of the joints with OC. It is also possible for a piece of bone or cartilage to become detached from the joint. If you see such a 'chip', it is considered OCD. Such a loose bone fragment can cause problems in the joint (in the long term), it can interfere with movement and cause inflammation and swelling. This depends on the location of the chip in or near the joint. Over the course of a horse's life, bone fragments can move and a chip that previously did not cause problems may eventually become problematic.

How do OC and OCD develop?

Both OC and OCD usually occur when a horse is still young, between the ages of six months and two years. The development of OC and OCD is partially genetically determined. But nutrition and exercise during rearing also play a significant role. Foals and young horses should have ample opportunities for movement and receive the right nutrition for their growth, with sufficient minerals for bone development. OC and OCD are usually found in the hock joints, knees, or fetlocks of a horse. Abnormalities can also be seen in the cervical vertebrae. Bone fragments can also result from overloading, a blow, or an accident, even later in life. The KWPN studbook is working on mapping the genetic predisposition for OC and OCD in their mares and stallions, so that breeders have a better understanding of what to expect.

Is a horse with OC or OCD always lame?

Usually, a horse with OC is not lame. It is the loose chips in OCD that can cause swelling and lameness over the years. A loose bone fragment can move within a joint and cause problems. If a hock, knee, or fetlock is swollen and warm, it is an indication of OC or OCD, but there may be other issues as well. The abnormalities of OC or OCD can only be seen on an X-ray. The likelihood of lameness due to OCD is greater than with OC.

Preventing OC and OCD with silicon

To prevent OC and OCD, it is important for young horses to grow up with plenty of (low-impact) movement. Additionally, they should receive nutrition with balanced minerals so that their joints, bones, and cartilage can grow optimally. Plenty of free movement stimulates blood flow to the cartilage and promotes healthy joint development.

When you start training young horses, you should gradually increase the intensity and duration of the training. Tendons, ligaments, joints, and bones need time to adapt to the load and stress. Overloading can lead to chip formation, OCD, and lameness. Adding silicon to support the joints at a young age is recommended. Research has shown that horses given silicon were less prone to injuries. Additionally, their structure was stronger compared to horses that did not receive silicon. OC and OCD depend on multiple factors, but using the mineral silicon helps support the structure. You can start giving this to the pregnant mare.

Treating OC and OCD

Many future sport horses are X-rayed around the age of 18 months. If chips are found during this process, they can often be surgically removed to prevent future issues.

If a horse is experiencing inflammation or pain due to OCD, joint injections can sometimes help reduce this. Pain relief and anti-inflammatories (for example, by adding natural cannabinoids from clove) through feed can help alleviate the symptoms. Veterinarians also regularly perform surgeries to remove bone fragments in horses that are already being ridden.