Locomotor disorders are very common in the equine clinic, which may be partly due to the different types of activities horses develop. Osteoarthritis (OA), commonly known as degenerative joint disease, presents an considerable role in the series of disorders of the musculoskeletal system and may be associated with other problems such as navicular syndrome, periostitis or osteochondrosis. This affection causes progressive deterioration of articular cartilage, accompanied by bone and soft-tissue periarticular changes. In fact, it results from a complex interaction between biochemical and biomechanical factors. The objective of this article is to review information about clinical and radiographic findings of OA, the biochemical and biomechanical changes manifested in the disease and the importance of the synovial fluid. Additionally, some information on other species is also presented. This review refers to Part 1 of a study whose sequence is entitled "Osteoarthritis in horses - Part 2: a review of the intra-articular use of corticosteroids as a method of treatment."
equine; degenerative joint disease; synovitis; cartilage degeneration; pathology of articular disease.