Developmental Orthopedic Disease (DOD)

By: Dr. Lydia Gray

Brief Description

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:

• angular limb deformities (ALD)
• physitis or epiphysitis
• subchondral bone cysts
• osteochondrosis (OC) which can progress to osteochondritis dissecans (OCD)
• cervical vertebral malformation or “wobbler’s”
• flexural limb deformities or “contracted tendons”

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.

Supplements that May Lend Support

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.

Possible Diagnostic Tests

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.

Prescription Medications Available

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®.

Other Management Suggestions

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.

Questions to Ask Your Veterinarian

• What can I do to prevent DOD in foals that I raise?
• Can I have a pre-purchase screening conducted for DOD on a young horse I’m thinking about buying?
• If a horse has been diagnosed with DOD, will he still make a good riding horse?

Additional Resources

Further Reading for You

From the SmartPak Ask the Vet Blog:

Developmental Orthopedic Disease (from AAEP Ask the Vet)

SmartPak strongly encourages you to consult your veterinarian regarding specific questions about your horse's health. This information is not intended to diagnose or treat any disease, and is purely educational.