Osteochondrosis Dissecans (OCD) in Horses

Published Dec. 7, 2022

What is Osteochondrosis in Horses?

Osteochondrosis (OCD) is a developmental condition in horses where the cartilage at the end of bones does not form properly. This leads to poor attachment of and defects in the cartilage within the joint.

OCD can be seen in any joint but is most commonly found in the stifle, hock, and fetlock. Often, lesions will affect both sides of the horse even if the lameness that goes along with them is not. OCD occurs during skeletal development before birth and within the first few years of life, but depending on the severity, no signs may be noted until years later. The genetics of OCD are not completely understood.

Symptoms of Osteochondrosis in Horses

Signs of OCD in horses include:

Swelling of the affected joint(s)
Lameness

It is possible that some horses with OCD will be asymptomatic (no symptoms), especially before training or an exercise program. Additional stress of exercise exacerbates the defect and may cause clinical pain.

Causes of Osteochondrosis in Horses

Much bone development occurs in the horse before birth with bones continuing to grow their first 1-2 years. Genetics likely affect the bone development prior to birth but there are many ways that OCD can be caused or exacerbated after birth including:

Fast growth
Higher calorie diets
Mineral imbalances in the diet
Imbalances in hormones
Trauma
Excessive exercise

How Veterinarians Diagnose Osteochondrosis in Horses

Diagnosis of OCD always starts with a thorough physical and lameness examination by a veterinarian. Following the exam, radiographs will identify the location and sometimes the severity of lesions. In some cases of OCD, the horse will not appear lame. Radiographs are often recommended during pre-purchase examinations to catch these sub-clinical cases.

Treatment of Osteochondrosis in Horses

The only way to cure OCD is surgical removal of the poorly attached cartilage in the joint through arthroscopy. Prognosis for return to athletic function is usually good after these interventions. If surgery is not an option or the defect is very small, the pain and discomfort associated with the OCD can be managed in several ways, including:

Non-steroidal anti-inflammatory medications (Bute, Banamine, Equioxx)
Joint injections with steroids and hyaluronic acid products (Legend, Hyvisc)
Regenerative joint treatments such as PRP, iRAP, and stem cells

Recovery and Management of Osteochondrosis in Horses

Horses with OCD are much more likely to develop arthritis secondary to the condition even after surgery. To help support them and prevent this, a consistent exercise routine is important. Hyaluronic acid products such as Legend and Adequan can be very beneficial as well. Anti-inflammatory medications and joint injections may become useful long-term to keep horses as comfortable and competitive as possible.