INFECTIOUS RHEUMATISM IN YOUNG ANIMALS. 97 



certain lucky cases, sometimes without any treatment whatever, the 

 symptoms become less acute, the appetite persists or improves, fever 

 diminishes, the condition of the joints remains stationary, and after the 

 lapse of several weeks there is ground for anticipating recovery. In all 

 cases, however, the convalescents remain thin and sickl}^ exhibit pain 

 and capricious appetite, and in very few cases indeed is there any economic 

 reason for keeping them alive. 



More frequently infectious rheumatism terminates by abscess forma- 

 tion in the joints. The articular cavity becomes filled with pus, the 

 tissues covering one of the synovial sacs soften, and the abscess opens, 

 discharging fibrinous clots; thin watery pus mixed with sjniovia, 

 and debris of articular cartilages or ligaments. Pyaemia is the final 

 complication when the patients are not slaughtered. 



In the cases comprised under the second heading the symptoms 

 appear more slowly and develop insidiously, the chief, viz., a tendency 

 to remain lying and difficulty in movement, long preceding the appear- 

 ance of exudative arthritis. The course depends chiefly on the nature 

 of the infective agent. In calves suffering from peripneumonia, calves 

 from stables in which epizootic abortion rages, rachitic calves or calves 

 suffering from severe diarrhoeic enteritis, the joints do not become 

 the seat of suppuration. 



In such cases the arthritis is of a simple exudative character, but 

 without microbic infection of the joint cavity. This form is less 

 dangerous, and is often curable provided the original cause be kept 

 in mind. 



Lesions. The lesions are always very marked, and are quite 

 different from those of simple rheumatism. The synovial membranes 

 and the periarticular tissues are always thickened, injected, inflamed, 

 and infiltrated. 



In more benign cases the synovial exudate from the joint cavities 

 is simply cloudy, contains no infectious germs, and proves sterile on 

 attempts at cultivation. In such cases there is no abscess formation. 

 But most frequently this stage of serous exudation is only temporary, 

 and the articular fluid, which at first seems sterile, may, when tested 

 some days later by means of cultures, reveal the presence of organisms. 

 The synovia accumulated within the joint sometimes contains fibrinous 

 flocculi, which are at first small, but later form veritable coagula, filling 

 up and thickly coating all the prominences of the joint and moulding 

 themselves on the extremities of the bones constituting the articulation. 

 Sometimes the cartilages undergo very rapid ulceration, the subjacent 

 layers of bone become inflamed, and the osteoarthritis which develops 

 is so severe and painful that the patients are forced to remain abso- 

 lutely still, • and are quite incapable of rising. The lesions may 



D.C. H 



