Pycsniic Infection 903 



immune. According to cle Bruin the disease may have its origin 

 in the articular serous membrane or in the bone marrow, and 

 may be either serous or purulent in character. It is observed 

 chiefly in the cow. 



It is believed that the infection reaches the articulations pri- 

 marily by being taken up by the veins from the uterus, probably 

 in the form of small thrombi, which, passing to the heart and 

 thence to the lungs, succeed in passing through the latter organs 

 and gaining the systemic circulation, through which they event- 

 ually reach the synovial membranes or marrow of the bone, 

 where the micro-organisms lodge and multiply to induce arthritis. 



As a rule poly-arthritis follows some recognizable puerperal 

 infection of the uterus, such as retained placenta, or other dis- 

 ease, followed by more or less evident metritis or vaginitis. In 

 some instances the disease follows an apparently normal puerpe- 

 ral period, presumably because some very small wound of the 

 mucosa of the genital tract, or other injury, has led to an infec- 

 tion which has escaped notice until the arthritis appears. 



The .symptoms of poly-arthritis usually appear at about 6 to 8 

 days after parturition, though they may be delayed for some 

 weeks. They consist chiefly of stiffness in the gait, accompanied 

 by more or less distinct lameness and difficulty in getting up. 

 Pain is very evident, and the animal assumes the recumbent posi- 

 tion for a large part of the time. There is well marked fever, 

 with the accompanying symptoms of loss of appetite, cessation 

 of rumination and a decreased secretion of milk. An examina- 

 tion of the uterus may reveal the presence of retained placenta, 

 or of a dark-colored fluid, which may or may not be fetid. 



The pain in the affected limb is .so great that the animal de- 

 clines to bear weight upon it so far as avoidable. The capsule 

 of the joint is distended and tender. The epiphyses of the bones 

 are sometimes swollen and painful. If more than one joint is 

 simultaneously involved, the movements of the animal become 

 exceedingly difficult and painful. The symptoms may be com- 

 plicated by metastatic inflammation, or ab.sce.s,ses of some of the 

 internal organs, which may cause edema of some of the depen- 

 dent parts of the body. 



The prognosis is variable. If the arthritis is serous in char- 

 acter, perhaps we might say if it is due to the irritation of the 

 bacterial products in the part rather than to the presence of 



