Developmental orthopedic diseases including OCD and physitis cause pain in growing horses. Early recognition and management prevent long-term welfare consequences.
Developmental orthopedic disease causes welfare harm during the critical growth period when young horses are developing the musculoskeletal system they will depend on for their entire working lives. OCD lesions in joints cause pain, joint swelling, and lameness that range from mild to severe. The pain of OCD is welfare-relevant and may be present from early foalhood, yet the absence of obvious lameness in mild cases can delay recognition and treatment.
Physitis — inflammation of growth plates at the distal radius, tibia, and cannon bones — causes painful swelling that is often externally visible. Affected foals may stand with altered posture to offload painful growth plates and may be reluctant to move normally. Dietary restriction to slow growth rate and reduce physeal stress is the primary intervention.
OCD lesions requiring surgery are identified arthroscopically, and surgical removal of loose fragments provides reliable welfare improvement in most cases. Conservative management of mild lesions — restricted exercise and dietary management — can allow spontaneous resolution in some lesions during the first year of life. Prognosis depends on lesion location, severity, and timing of intervention.