CHAPTER XIV 



THE GENERAL INFECTIONS OF THE GENITAL 

 ORGANS OF CATTLE 



The mammalian genital tract opens freely upon the ex- 

 terior, rendering it possible for any infection upon the ad- 

 jacent body surface, capable of growing within the genital 

 tract, to invade it, either actively or passively through the 

 agency of a bearer (copulatory organs of the opposite sex 

 during coitus, surgical instruments, hands of operator). 

 Vastly more important, as far as at present known, is the 

 transmission of important infections from the alimentary 

 and pulmonary tracts, through the blood stream, to the geni- 

 tal tract. Thence the infection is carried, in the female, 

 back to the alimentary tract of the fetus. That is, as will be 

 more fully discussed when considering fetal infections, if 

 there is infection in the uterus of the pregnant female 

 (which is the rule) it tends to penetrate the thin chorion 

 and amnion and to be swallowed promptly by the fetus, 

 along with the amniotic fluid. If the fetus has sufficient 

 vigor, the bacteria are harmlessly included as a component 

 part of the meconium, to be expelled soon after birth ; if dis- 

 ease of the fetus occurs before birth, and the gastrointes- 

 tinal epithelium is destroyed or devitalized, infection ensues. 

 The bacteria may then enter the blood stream, to be lodged 

 later in the articulations (arthritis) but, since they were 

 originally derived from the genital tract of the mother, tend 

 logically to return to the genitalia. If the infections within 

 the uterus of the pregnant cow commonly invade the ali- 

 mentary tract of the fetus, it follows that subsequent to 

 birth the same infections may be expelled from the diseased 

 uterus, contaminate the milk, be swallowed by the calf, and 

 cause disease having the same peril for it as if the infection 

 had been swallowed prior to birth. 



Each year adds to the number of known species of micro- 

 organisms capable of invading the genital tract of cattle 

 and of other domestic animals and, according to the best 



