264 Veterinary Obstetrics 



moval and the disinfection of the uterine cavity, fertilization 

 occurred in due season. Very frequently, when a retained fetus 

 has undergone purulent decomposition and is later removed 

 surgically, it is found that the cotyledons are all necrotic and, 

 dropping off, are expelled along with, or following, the fetus. 

 In due time the cow again conceives. The loss of the cotyledons 

 does not lead to sterility ; the septic metritis or other disease 

 accompanying the retained placenta may cause .sterility by in- 

 ducing .salpingitis followed by occlusion of the oviducts. Other 

 anatomical changes may occur, rendering the patient sterile. 



Our attention is to be directed to measures which may prevent 

 the loss of the cotyledons, or, if they have sloughed away, to a 

 restoration of the uterus to its normal health. 



9. Vaginitis. 



Though the normal .secretions of the vagina are feebly alkaline, 

 any disease which may affect this organ and induce purulent or 

 other disease discharges tends to change the reaction of these, 

 through bacterial influence, and render them acid, a condition 

 which is inimical to the life of spermatozoa. It is held that, 

 normally, the copulative tract of domestic animals contains more 

 or less bacteria, the number and variety being quite abundant in 

 the vulva, but decreasing both numerically and in variety as the 

 OS uteri is approached. Generally, also, it appears that the 

 pathogenic power of bacteria diminishes as the os uteri is ap- 

 proached so that, in the anterior portions of the vagina, the bac- 

 teria present are largely saphrophytic. The bactericidal power 

 of the vaginal walls gradually increases toward the anterior ex- 

 tremity, to become complete in the normal organ in the cervix 

 uteri, beyond which the genital tract is normally free from bac- 

 teria. When, however, the copulative tract becomes invaded by 

 pathogenic bacteria, their products, coming in contact with the 

 -spermatozoa, tend to destroy the latter and thus induce sterility 

 by the destruction of the male cells before they have reached the 

 uterine cavity. 



It therefore becomes essential that, in cases of inflammatory 

 disease of the vagina, the infection should first be controlled and 

 eliminated before copulation is permitted. Not only should this 

 be done from the standpoint of the fertilization of the ovum, but 



