arthritis

Inflammation of a joint. An increase in the amount of synovial fluid in the joint is a result of this inflammation. Accumulation of synovial fluid in the fetlock joint is called a "wind puff" or "wind gall." In young horses, a swelling in the fetlock joint, particularly on the front of the joint where the cannon and long pastern bones meet, is called a "green osselet." This swelling is a result of inflammation and reactive changes of the front edges of these two bones and adjacent cartilage. If the green osselet does not heal, a "chronic osselet" might develop with a permanent build-up of synovial fluid in the joint and inflammation and thickening of the joint capsule over the damaged area with secondary bone changes following the initial inflammation.