Developmental Orthopedic Disease (DOD) is the term used to describe most general growth disturbances of growing horses. The underlying problem in these growth disturbances is the failure of cartilage to mature and develop into bone properly. Growth disturbances that fall under the heading DOD generally include the following:
A combination of genetics, nutrition and exercise leads to DOD, so horse owners should pay particular attention to breed, conformation, the diet of the pregnant and lactating mare, the diet of the growing horse, and husbandry and housing practices.
Research has shown that overfeeding calories (or energy) is one of the major factors leading to DOD. While it may be tempting to feed large amounts of grain to encourage a young horse to grow faster or bigger, it is better to aim for steady growth and an ideal body condition score. This may mean cutting back on grain and instead feeding a multi-vitamin/mineral supplement balanced for the type of forage fed, to ensure the growing horse receives the appropriate amounts and ratios of key nutrients. Supplementing with specific minerals such as Calcium, Phosphorous, Copper and others should only be done on the advice of a veterinarian or nutritionist and only if ration analysis shows these specific nutrients to be lacking.
DOD is usually diagnosed based on clinical signs and x-rays. These signs may include noticeable joint swelling, growth plate swelling, crooked limbs or contracted tendons. In some young horses, lameness may be the first and only sign of a problem, and this lameness may not appear until the horse has been put into training.
Depending on the type of growth disturbance and its severity, some horses may require a prescription medication for pain such as bute (phenylbutazone). Certain types of DOD may also benefit from the injectable medications Adequan® or Legend®.
Housing and management are important both in the prevention and treatment of the various forms of DOD. In addition to providing a proper diet, special attention should be paid to turnout, controlled exercise, foot care, and the body condition score of the growing horse.