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Diagnosis
Conditions or ailments that are the cause of a problem that you see - your observation.

Your vet may diagnose

Osteochondrosis, OC, Osteochondritis Dissecans, OCD

Summary

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.

my vet's role

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Treatments May Include

These treatments might be used to help resolve or improve this condition.

Very Common
Less Common
Rare
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PROGNOSIS AND RELEVANT FACTORS

Good to poor, depending on the specific joints affected and the severity of the problem.

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I might observe

You might make these observations when a horse has this condition.

Very Common
Less Common
Rare
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Questions To Ask Your Vet:
  • Why did my horse end up with this condition?
  • Are my other horses at risk of developing the condition?
  • What happens if nothing is done?
  • What can I change in my breeding and management to reduce likelihood of this condition?
Prevention

Genetics: Choose lines of horses that do not have a high incidence of the condition.

Management: Provide appropriate nutrition to pregnant mares and growing foals. Do not overfeed or over nourish growing foals.

Pre-purchase exams: Be on the lookout for this condition. Have a PPE performed before purchasing a horse.

further reading & resources


Related References:

Koenig TJ1, Dart AJ, McIlwraith CW, et al. Treatment of experimentally induced osteoarthritis in horses using an intravenous combination of sodium pentosan polysulfate, N-acetyl glucosamine, and sodium hyaluronan. Vet Surg. 2014: 43(5):612-22.

Author: Doug Thal DVM Dipl. ABVP