In a recent post, we gave an example of a horse that had been previously diagnosed with OCD Lesions and many of you have had questions about what OCD Lesions are so I wanted to take a few minutes to elaborate on that.

OCD lesions often develop in the first year of life but are often not noticed until much later when the horse is put into training. The developing bone of a young horse requires a specific function where the cartilage cells at the end of the bone turn into bone cells and create the lengthening effect of the bone required for growth. OCD lesions occur when this process doesn't properly take place and they will often develop with rapid growth spurts. Factors that influence the development of OCD lesions are: high energy/high carb diets in growing horses, trauma to a joint, an above average body weight, genetics and nutritional imbalances.

Horses with OCD lesions will experience varying degrees of lameness and OCD lesions are often met with surgical treatments, and with varying degrees of success. One study performed on Thoroughbred weanlings and yearlings to measure the affects on future racing performance showed that OCD Cases performed less successfully as racehorses, and that the age at the time of surgery did effect the performance.

So far, we have focused on the development of OCD lesions in young horses but older horses are not immune to the effects of these imbalances, and here's why. As the animal matures and ages, silicon (a component necessary for collagen production for the initial formation of bones and connective tissue) becomes less prominent. A lack of support in this area may compromise the flexibility and elasticity of the bones and also contribute to inadequate tissue production in, and around the joints. The subchondral bone, which is the soft portion of the bone that forms where the cartilage begins, may be affected when it becomes overly dense. That is, without silicon to produce the elastic effect that portion of the bone needs, the more susceptible it is to damage as it isn’t able to effectively “absorb” the shock. Connective tissues like tendons, ligaments & cartilage may also be negatively affected as their ability to heal and repair is diminished in the absence of silicon.

When thinking about the mineral needs of a young growing horse, think in terms of ratio of one mineral to another. It doesn't do any good to overload calcium if the phosphorus and other elements required for proper absorption and utilization are not in check. The good news is that if the mineral and nutritional requirements are in balance, the body of a growing foal will often self correct the lesions that form from one of the other common causes.

For more information on what you can do to more readily support the development of healthy bone and connective tissue, see OSTEO-FUEL by TLC Animal Nutrition, Inc.




  1. Treatment of osteochondrosis dissecans in the stifle and tarsus of juvenile thoroughbred horses. https://www.ncbi.nlm.nih.gov/pubmed/25243728