DEVELOPMENTAL ORTHOPEDIC DISEASE (DOD)
The term “developmental orthopedic disease” (DOD) applies to a collection of bone and joint abnormalities that arise when the conversion of cartilage to bone is disrupted in a young, growing foal. Osteochondritis dissecans (OCD), for instance, occurs when cartilage is too thick to be sufficiently permeated by blood vessels and the bone beneath it develops weak, empty spots referred to as “lesions.” In epiphysitis, areas of growing cartilage at the end of bones cannot support the youngster’s weight, leading to inflammation in areas under stress.
Particular breeds and bloodlines are genetically prone to DOD, but a highprotein diet greatly increases any youngster’s risk, as does lack of turnout and/or forced exercise, such as excessive longeing or ponying. DOD is managed with dietary changes and, in advanced cases, surgery to remove damaged cartilage and bone.
With early intervention and care, many foals with DOD can grow up to be sound, useful horses, but some studies suggest that the damage done to an immature joint, particularly scoring by small osteochondral fragments, can lead to arthritis later in life.
Making sure a young foal has a proper diet and a sensible activity level not only will help prevent DOD in the short term but can pay off in soundness years down the road. If your horse is now grown, but you know he had DOD as a youngster, keep an eye out for early signs of arthritis so you can begin intervention as soon as possible.
Torque (twisting force) is particularly tough on joints, so limit the amount of work done in small circles or with tight turns.
Sudden, massive inflammation in the wake of a severe injury can lead to the destruction of cartilage, and it sets the stage for the development of arthritis.