=The diagnosis= is based on the position and direction of the dilated synovial sheath. =Treatment= is identical with that of other cases of chronic synovitis. DISTENSION OF THE BURSAL SHEATH OF THE FLEXOR TENDONS. This condition is rare. It is announced, as in the horse, by a dilatation of semi-conical form, the apex of which is situated opposite the lower margin of the carpal sheath, the base extending as high as the infero-posterior third of the radius. The dilatation is more marked on the inner than on the outer side of the limb. Distension of the synovial sheath of the common extensor of the digits in the fore limb and of the extensor of the external digit is still rarer than the preceding conditions. TRAUMATIC SYNOVITIS—“OPEN SYNOVITIS.” When an injury in the neighbourhood of a joint penetrates deeply, it may implicate either the synovial sheath of a tendon or the synovial membrane of a joint. If the body inflicting the wound is aseptic, a condition which in accidental wounds is rare, the wound may have no grave consequences. Usually, however, the body producing the injury is infected, and the infection rapidly extends throughout the tendon sheath or synovial sac. In the first case, traumatic suppurating synovitis of a tendon sheath is the result; in the second, a suppurating articular synovitis arises, which soon becomes complicated with injury of the articular cartilages, ligaments, etc. (traumatic arthritis). The primary lesion may only affect the periarticular region, not directly extending to the synovial membranes, and only after an interval of some days may symptoms of suppurating synovitis or suppurating arthritis appear, in consequence of progressive invasion of the parts by specially virulent microbes. TRAUMATIC TENDINOUS SYNOVITIS. Suppurative inflammation of the synovial bursæ of tendons in consequence of wounds most commonly affects the sesamoid sheaths of the front or hind limbs; more rarely, the tendon sheaths of the hock or knee; and, exceptionally, the small synovial sheaths of the extensors of the metacarpus and phalanges, etc. Such inflammation follows injuries with forks, harrow teeth, or any sharp foreign body. It is characterised by the existence of a fistula or wound, indicating the course taken by the body inflicting the injury, from which at first normal synovia escapes. Later, however, the discharge becomes turbid, and after the second day gives place to a clotted, serous, or purulent fluid. A diffuse, œdematous, warm, painful swelling very rapidly develops around the injury. The animal is more or less feverish and lame. The swelling soon extends throughout the entire length of the infected synovial sheath. The patient loses appetite, and unless treatment is promptly undertaken, complications supervene which often necessitate slaughter. The prognosis is always grave.