98 



RHEUMATISM. 



remain stationary at this point. In other cases suppuration occurs in 

 the articulation itself, the wall of the synovial cavity, the periarticular 

 tissues, and the skin soften ; then the abscess breaks, giving rise to open 

 suppurating arthritis. Animals are rarely kept long enough to become 

 so gravely affected ; many die before this stage, and the others are 

 usually slaughtered. Moreover, they rapidly perish from exhaustion 

 and from visceral complications of a py^emic character. 



In many cases post-mortem examination reveals nothing whatever in 

 the region of the umbilical cord (through which infection has occurred), 

 but the germs of infection may be found in the blood or general 

 circulation ; or again, careful investigation may show ulceration of the 

 umbilicus, lesions of omphalitis, of ascending umbilical arteritis in 



Fig. 62. — Ulceration of the articular cartilage in infectious rheumatism. 



consequence of infection of the thrombus, of umbilical phlebitis, or of 

 infective peritonitis, etc. The infectious agent reaches the liver through 

 the blood-vessels, then attains the posterior vena cava, after which the 

 infection assumes the gravest possible character, producing complications 

 like arthritis and purulent infection, with the formation of multiple 

 abscesses in the depths of the viscera. 



The Staphylococcus aureus and various streptococci are the most 

 frequent but not the only causes of these infections. 



The diagnosis is not difficult, provided the disease be not mistaken 

 for true rheumatism. As true rheumatism is very rare in young animals, 

 and as, on the other hand, attention is aroused by the presence of 

 lesions of the umbilicus and by the existence of diarrhoeic enteritis, 

 rachitis, etc., there is seldom room for doubt. 



Prognosis. The prognosis is extremely grave whenever the case 



