Osteochondrosis causes variable degrees of joint effusion and lameness. Arthroscopic debridement of the lesions provides the best long-term outcome. Articular fracture or joint instability following collateral ligament rupture causes severe joint effusion and lameness. Internal fixation combined with external coaptation is the treatment of choice. Degenerative joint disease in young animals has a guarded prognosis. Arthroscopy combined with medical therapy may slow down the disease process. Degenerative joint disease involving the distal interphalangeal joint has a good prognosis following joint resection.