bly these materials are soon absorbed and
resolution occurs. In rarer cases the thickening and congestion of the
membrane increases, and the articular capsule becomes so distended with the
increased synovia and accumulated inflammatory discharges that a kind
of chemosis occurs. In other words, there oozes through, without actual
rupture of the membrane, a thin, blood-stained, and purulent-looking
discharge.

It is an important point to note that in cases of synovitis the fringes of
the synovial membrane become swollen and blood-injected, forming noticeable
red elevations at the margins of the cartilages. It is then that the
diseased condition soon spreads and runs into arthritis.

Further, it is important, especially with regard to the question of the
degree of pain and lameness likely to be caused, to note that often
granulations are thrown out upon the looser folds of the membrane. As
these increase in size they come to form fringed and villous membranous
projections inserting themselves between the bones forming the
articulation. In such cases there is no doubt that the intense pain
sometimes observed in these cases is due to pinching of these prolongations
of the synovial membrane by the opposing bones of the joint.

_Symptoms and Diagnosis_.--Acute synovitis of a joint leads to heat of the
parts, pain, distension of the capsule, and, where the joint may be easily
felt, fluctuation. In the articulation with which we are dealing, however,
these last two symptoms are not easily detected, for the surrounding
structures--namely, the lateral and other ligaments of the joint, the
extensor pedis tendon in front, and the perforans behind, together with the
dense and comparatively unyielding nature of the skin of the parts--are
such as to prevent distension and fluctuation becoming marked to a visible
extent. We are able to diagnose the case as one of foot lameness, and, with
a history of a severe blow or other injury, are able to assume that this
condition, perhaps attended with periostitis, is in existence.

When other symptoms present themselves diagnosis may be more certain. The
animal becomes slightly fevered, throbbing pains in the joint manifest
themselves by irregular pawing movements on the part of the patient. The
animal comes out from the stable stiff, even dead-lame, and the limb is
carried with the lower joints semiflexed. The breathing is hurried and the
pulse firm and frequent, while in a bad case patchy per