Feeding Foals and Young Horses to Avoid Developmental Orthopedic Disease (DOD)

Breeding decisions involve months of pedigree research, careful planning, and significant investment. When a foal finally stands and nurses for the first time, it marks an important milestone—but only the beginning of the horse’s development.

Developmental orthopedic disease (DOD) affects the bones and joints of growing horses, often showing up as joint swelling, limb deviations, or changes in movement. While genetics and management both play a role, nutrition remains one of the most powerful tools horse owners can use to support healthy skeletal development.

This article explains what developmental orthopedic disease (DOD) is, its causes, how it affects growth, and why proper nutrition is vital for reducing risk.

What Is Developmental Orthopedic Disease in Horses?

Developmental orthopedic disease (DOD) refers to a group of conditions that affect bone, joint, and cartilage development in growing horses.

These issues develop when normal bone growth and cartilage formation become compromised, often due to rapid growth, nutrition, genetics, and exercise. While mild cases can improve with proper management, more severe cases may impact long-term soundness and performance.

Common forms of DOD include:

Osteochondrosis (OC/OCD): A disruption in normal cartilage development that can lead to loose fragments (“joint mice”) within the joint.

Physitis (Epiphysitis): Inflammation and swelling of the growth plates, most commonly seen in the fetlock or knee.

Flexural Limb Deformities: Tight or contracted tendons, often resulting in conditions such as club feet.

Angular Limb Deformities: Abnormal limb alignment, including conditions like knock-knees or bowlegs.

Subchondral Bone Cysts: Fluid-filled lesions that develop within the bone beneath the joint surface.

Cervical Vertebral Malformation: A neurological condition, commonly known as “Wobbler Syndrome,” that affects coordination and balance.

The signs of the common forms of DOD in young horses may include:

  • Joint swelling (especially around the knees or hocks) 
  • Stiffness or lameness 
  • Uneven limb alignment 
  • Reduced performance potential over time 

What Causes Developmental Orthopedic Disease in Growing Horses?

Young horses grow quickly through areas called growth plates. When growth occurs too rapidly or unevenly, it places excessive stress on developing bones and joints, increasing the risk of structural issues.

However, DOD rarely has a single cause. Instead, it develops from a combination of factors, including genetics, growth rate, exercise, and nutrition.

Some of the key contributors to DOD include:

  • Excess caloric intake: Overfeeding calories—especially from high-starch, high-sugar feeds (NSCs)—can accelerate growth beyond what developing bones and joints can safely support.
  • Rapid or uneven growth: Growth spurts place added strain on developing joints, particularly when body weight increases faster than bone strength.
  • Mineral imbalances: Incorrect levels or ratios of key minerals, including calcium, phosphorus, copper, and zinc, can disrupt normal bone and cartilage development.
  • Genetics: Some bloodlines—especially Warmbloods, Thoroughbreds, and Standardbreds—are more prone to these issues, pointing to a genetic influence in conditions like OCD.
  • Exercise and trauma: Both excessive confinement and high-impact exercise can place abnormal stress on developing joint cartilage, increasing the risk of lesions.
  • Conformation: Poor structural alignment can create uneven pressure on growth plates, contributing to conditions such as physitis.

How Does Feeding Affect Growth and Bone Development in Horses?

Nutrition plays a direct role in growth rate, bone strength, and joint development in young horses. Even well-intentioned feeding programs can increase the risk of developmental issues if they prioritize rapid weight gain or appearance over steady, controlled growth.

The goal is to provide a balanced diet with appropriate caloric intake, controlled energy sources, and well-balanced nutrients to support consistent development and reduce the risk of developmental orthopedic disease.

Several key nutritional factors influence how young horses grow and develop:

Calorie intake: This directly drives growth rate. When intake exceeds requirements, young horses gain weight too quickly, increasing the load placed on immature bones and joints.

Energy source (NSCs vs. fat and fiber): Diets high in non-structural carbohydrates (NSCs), such as starch and sugar, can contribute to rapid growth and metabolic fluctuations. In contrast, fat- and fiber-based energy sources provide slower-release calories that support more controlled growth without sharp spikes in blood glucose.

Minerals: Minerals play a structural role in bone development. Calcium and phosphorus form the foundation of bone tissue and must remain properly balanced, typically at a ratio of 1.5:1 to 2:1. Trace minerals such as copper and zinc support cartilage formation and help maintain proper joint structure.

Protein and amino acids: Growing horses require essential amino acids, such as lysine, methionine, and threonine, to support muscle and tissue development. While high protein does not cause DOD, imbalanced or low-quality protein can impair proper development.

Vitamins: Vitamins also support growth and bone health. Vitamin D aids calcium absorption, while vitamin A supports tissue development.

How To Feed Foals and Young Horses: Feeding Strategies for Steady, Healthy Growth

Feeding strategies directly influence how young horses grow and develop, making a balanced approach essential for long-term soundness.

Balance Energy and Nutrients: Feeding the growing foal requires a careful balance of calories and nutrients. Too many calories—especially from starch and sugar (NSCs)—can accelerate growth and increase the risk of developmental orthopedic disease (DOD). 

Conversely, inadequate intake of key nutrients, particularly trace minerals, can impair proper skeletal development. The goal is to provide enough calories to support steady growth while delivering the right balance of vitamins, minerals, and protein needed to build strong bones and joints.

Start with a Forage-First Foundation: High-quality hay or pasture should form the foundation of the diet. Forage supports digestive health and provides a consistent base of nutrition for growing horses.

Support the Mare to Support the Foal: Young foals rely heavily on the mare’s milk. Supporting the mare’s nutrition directly impacts the foal's health, as milk production and quality depend on adequate energy, protein, and mineral intake. Feeding a low-NSC, nutrient-dense ration designed for lactating mares helps ensure the foal receives essential nutrients during this stage.

Fill Nutritional Gaps with Creep Feeding: Mare’s milk may not fully meet a growing foal’s needs—especially in fast-growing or underweight individuals. A nutrient-dense creep feed helps fill these nutritional gaps and supports consistent development during the first few months of life.

Transition to Balanced Growth Diets: As the foal matures and relies less on milk, the young horse's diet will transition to a balanced concentrate-and-forage diet. Providing high-quality protein and maintaining proper mineral balance and caloric intake help support healthy growth.

Use Ration Balancers for Easy Keepers: Some young horses gain weight easily. In these cases, a ration balancer delivers essential nutrients without excess energy, helping maintain a more moderate and controlled growth rate. This approach is especially useful for horses showing early signs of physitis or other DOD-related changes.

Avoid Over-Restriction of Feed: Avoid underfeeding or using low-quality forage to slow growth. It is a common misconception that reducing grain and feeding low-quality hay supports recovery from DOD. Severe calorie restriction can limit essential nutrients and hinder development. Instead, adjust calorie levels accordingly while maintaining a nutrient-dense diet, such as using a ration balancer to support steady growth without excess calories. 

Monitor Growth and Body Condition

Regularly monitoring body condition helps determine when diet adjustments are needed.

Young horses should maintain a body condition score of 4–5, appearing lean and athletic with ribs easily felt but not prominent. Excess weight (BCS 7 or higher) increases strain on developing joints and raises the risk of developmental orthopedic disease.

Because growth rates and nutrient needs change quickly, feeding programs should be evaluated and adjusted as the young horse grows.

Support Healthy Growth and Reduce DOD Risk with Tribute Superior Equine Nutrition

Tribute Superior Equine Nutrition offers feeding solutions designed to support steady growth and proper nutrient balance in broodmares, foals, and young horses.

Essential K®: A low-NSC ration balancer designed to provide essential vitamins, trace minerals, and amino acids without excess calories for broodmares or young horses needing nutrient support without added calories.

Growth Pellet: A low sugar/starch, high-fiber, and higher-fat feed formulated for growing horses and broodmares. Supports bone, cartilage, and tissue development while promoting controlled growth and improved nutrient absorption.

Alfa Growth®: A nutrient-dense, higher-fat feed designed for young horses and broodmares on alfalfa-based diets. Provides balanced minerals and essential nutrients to support healthy bone and joint development during growth.

Foal Foundation™: A milk-based creep feed designed for foals up to 3 months of age. Provides high-quality protein, amino acids, vitamins, and organic minerals to support early growth and help fill nutritional gaps from mare’s milk.

Growth Textured: A higher-fat, nutrient-rich feed for growing horses and broodmares that need additional calories. Supports bone, cartilage, and tissue development while promoting digestive health and steady growth.

Every young horse develops differently. Working with an equine nutritionist or using Tribute Equine Nutrition’s free personalized feed plan can help create an evolving feeding program that keeps caloric intake, mineral balance, and growth rate aligned—supporting soundness now and long-term performance later.

References

Article By:
Nicole Rambo, Ph.D
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