ORGANS OF LOCOMOTION 137 



bundles and fibers, and rarely of necrosis of the intra- 

 muscular fibrous tissue. The muscle fibers are affected 

 with parenchymatous or fatty degeneration, and the 

 surrounding artericles and capillaries are engorged. 



Symptoms. The principal symptom consists of 

 expression of pain, especially evident when the animal 

 moves. Locomotion is interfered with, and there is a 

 shifting lameness. Some cases of so-called paralysis 

 resulting in dragging of the hind legs are probably mus- 

 cular rheumatism. If the disease is sufficiently extensive 

 the affected animals refuse to eat. Muscular rheumatism 

 is differentiated from trichinosis by the periodic shifting 

 lameness of rheumatism and by the general absence of 

 systemic disturbances. It may be necessary to dis- 

 tinguish it from rickets, which is not difficult, since the 

 latter is a disease affecting the bones. 



Treatment. Provide good quarters where the animal 

 will not experience wide variations of temperature within 

 a short time. Laxatives and some f orm of salicylates or 

 their derivatives are usually of value, but must be given 

 judiciously to avoid impairment of digestion. 



Articular Rheumatism 



Articular rheumatism sometimes occurs in swine. 

 This condition affects swine that have been unduly 

 exposed, but probably the exciting cause is infection. 



Articular rheumatism is essentially an inflammation 

 of the periarticular structures, including the synovial 

 membrane. The inflammation may be serous, fibrinous, 

 or hemorrhagic, and in extreme cases, it may become 

 purulent. The exudate is accumulated in the peri- 

 articular structures and occasionally in the joint cavity. 

 Thj synovia become admixed with the inflammatory 

 exudate and appears turbid, bloody, or purulent, and 

 may contain coagulated fibrin; the articular surfaces are 

 rough. In cases of long standing the articulation is 

 surrounded by varying quantities of fibrous tissue which 

 may cicatrize and cause deformity. Various articulations 

 are affected, but the lesions are principally confined to 

 the carpal, tarsal, stifle, and fetlock joints. 



