eq, 
DISEASES OF THE JOINTS 415 
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 un- 
yielding 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 irre- 
gular 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 perspiration breaks out at intervals on 
various parts of the body. If with this we get a puffy and 
tender swelling in the hollow of the heel, our diagnosis may 
be certain at any rate as to the existence of joint trouble, 
although, from reasons we have given, we may not be able 
to mark its exact nature. 
2. Chronic.—Simple synovitis may in many instances 
become chronic. In this case we have simply a pouring 
into the synovial capsule of serous fluid, and with it an 
increased quantity of synovia—this time with an absence 
of the usual inflammatory phenomena. Beyond the swell- 
ing of the capsule there is little to be noticed. The joint 
becomes perhaps a little weaker, but pain or tenderness and 
heat are entirely absent. Such a condition, by reason of 
the natural rigidity of the parts, is not to be observed in 
the foot, although at times it must most certainly occur. 
Examples of such a condition are to be found in bog-spavin, 
