Osteochondrosis (OC) refers to abnormalities of developing bone; resulting in bone and/or cartilage defects at the joint surface. It is a highly prevalent, multifactorial type of developmental orthopedic disease (DOD)
of growing horses.
OC occurs very frequently warmblood horses. The prevalence of OC in Dutch warmblood horses between 1-4 years old was estimated to be about 25% of the population. In Thoroughbreds, the overall prevalence of OC is 23%.
OC is an aseptic ischemic necrosis, and has most frequently been described as failure of endochondral ossification, resulting in either Osteochondrosis Dissecans (OCD)
or Subchondral Bone Cysts
. OC most frequently occurs in the hock, stifle and fetlock joints. Less commonly, it can occur in the scapulohumeral, hip and elbow joints.
Clinical signs of OC may or may not be obviously present, however when they are, the most commonly observed include joint effusion and lameness.