588 Diseases of the Genital Organs 



non-pregnant cow through eating food or drinking water 

 contaminated by genital discharges from a diseased animal. 

 It has not been shown that infections discharged from the 

 genital tract of a diseased cow will traverse the vulva and 

 vagina of a contiguous healthy cow and cause intra-uterine 

 disease. 



There is abundant clinical evidence that an infected bull 

 is competent to transmit infection to the uterus of a healthy 

 cow during coitus and either establish a disease (cervicitis, 

 metritis, salpingitis) which inhibits conception, or when the 

 infection is less mild, establish disease within the pregnant 

 uterus to end finally in abortion or other disaster. 



It has apparently been shown experimentally that serious 

 uterine or other genital infection may be established in 

 healthy non-pregnant animals by introducing into the blood 

 stream or into the subcutaneous tissue, and thence indirectly 

 into the blood stream, pathogenic bacteria having an affinity 

 for the genital organs. Thus the experiments of Bland 1 have 

 apparently shown that by injecting large doses of B. abortus 

 cultures into non-pregnant cows and heifers the fertility of 

 the latter is seriously lowered, that a large percentage of the 

 animals fails thereafter to conceive, or, if they conceive, the 

 embryo is absorbed or expelled unseen. This may be appar- 

 ent only, since the experiments were entirely too inaccurate 

 to afford a secure basis for judgment. If the experiments 

 actually caused the apparent harm, it may have been di- 

 rectly by the B. abortus reaching the genital canal, or indi- 

 rectly through lowering the resistance of the patient to or- 

 ganisms already resident in the genital tract. In studying 

 the infections of the uterus during the post-puerperal period, 

 it is important to bear in mind their various possible or 

 probable sources, because evidently the prophylaxis of the 

 various types of disease occurring during this period must 

 depend upon the power or desire to eliminate the dangerous 

 infections existing during the puerperal period, and to 

 avoid coital infection by excluding seriously diseased bulls. 



The variety of organisms which may cause disease of the 



'Second Report on the Epizootic Abortion Experiments, i*.»i 1-1916. 



