DOD, OCD What Do All These Initials Mean?
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Pet Column for the week of March 27, 1995
Office of Public Engagement
2001 S. Lincoln Ave.
Urbana, Illinois 61802
Phone: 217/333-2907
By Linda March
Information Specialist
University of Illinois
College of Veterinary Medicine
Developmental Orthopedic Disease (DOD) is the larger category that encompasses
osteochondritis dissecans (OCD). Both have to do with bone abnormalities of young,
growing horses.
"OCD is one aspect of a syndrome of degenerative joint disease, contracture of tendons,
leg malalignment, and/or club feet. If the owner sees any one of these problems, the horse
may be susceptible to the rest," says Dr. R.D. Scoggins, equine Extension veterinarian at
the University of Illinois College of Veterinary Medicine at Urbana.
Normally, as an animal grows, the soft cartilage at the ends of long bones matures and
remodels to become hard. With OCD the cartilage does not become hard and instead
breaks down, causing lamenesses. This breakdown of cartilage can lead to joint erosion,
lack of cartilage on the joint surface, fluid build-up in the joint, bone cysts, bone-to-bone
contact and/or pain.
OCD affects young horses, generally those that will have a mature height of over 15 hands.
Although it has been detected in some horses as young foals, it usually causes problems for
the animal about the time they enter training.
There are many factors that contribute to this disease syndrome. The genetic predisposition
for rapid growth seems to be one. When breeding, research the stallion's background for
any history of affected offspring, especially if the horse's mature height will be over 15
hands high.
Correct mineral balance in the diet is also important. Dr. Scoggins stresses, "It is critical that
the brood mare is fed a diet with the right mineral balance and energy requirement to give
the foal a good start in life."
Early detection of the problem is key to an effective treatment. Watch for recurrent
lameness, especially if it shifts from one leg to another. The shoulder, hock and stifle joints
are frequently involved. Bog spavin (boggy hocks) or puffy joint effusion (fluid in the joint
space) may also be a sign of OCD.
Your veterinarian can use contrast radiographs, nuclear scintigraphy, and/or endoscopy to
help detect OCD lesions.
Some cases are candidates for surgery and some will respond to medical treatment. If you
see lameness, joint swelling or possible leg malalignment, have your veterinarian check the
horse.
Proper feeding of the young, growing horse can help prevent OCD. For example, the feed's
copper content should be analyzed. Copper oxide is not absorbed by horses, while copper
sulfate is more readily utilized by horses. Over-supplementation of minerals has also been
linked to OCD lesions. If you need help with feed analysis, call your veterinarian, an equine
nutritionist or your area Extension office.
Foals can be started on creep feed, but energy and protein levels must be kept in check. If
the foal has to carry excess fat on its immature body frame, problems associated with OCD
can occur.
"Growth spurts in the foal, as well as sick and malnourished youngsters significantly increase
the risk for tendon contractures and abnormal long bone development," notes Dr. Scoggins.
OCD is primarily a disease of the young, although it may not show up in the animal until
three to four years of age. Bone cysts will take a couple of years to manifest signs of
increased frequency and severity of lameness.
If you have any questions about OCD, call your veterinarian.