Development of the limb bones in a young horse requires a soft, cartilage template be converted to bone, a process known as endochondral ossification.
Osteochondrosis (OC) generally refers to the abnormal transformation of this cartilage template to bone. OC/OCD is a common developmental disorder and seen most commonly in young horses. It is an orthopedic disease of the bone-cartilage junction under the joint surface that damages the cartilage on the joint surfaces.
Osteochondritis Dissecans (OCS), specifically refers to this abnormal transformation occurring on or within a joint, and involving loose or undermined cartilage or bone within the joint.
Exactly why OC/OCD occurs in horses is still not fully understood but many factors have been associated, including genetics and over-feeding.
OC/OCD sometimes leads to lameness, pain, joint swelling and ultimately arthritis. In other cases, it does not cause obvious problems and is found “incidentally” in x-rays taken for another reason.
The cause of OC/OCD is not well understood. There are a variety of genetic and environmental factors that contribute to it. Over-nutrition may be a significant contributing factor. Studies suggest that foals turned out in pasture have a lower incidence of this problem.
Diagnosis is usually made through veterinary exam and x-ray.
Treatment ranges from nothing to changes in management (feeding) to surgical (arthroscopic) removal of loose cartilage and poor quality bone.
Other Diagnoses Considered
Treatments May Include
Prognosis & Relevant Factors
Good to poor, depending on the specific joints affected and the severity of the problem.
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