Infectious Abortion of the Cow 501 



to spread first to those cows which are nearest to the aborted 

 animal. In some outbreaks which have been recorded, it has 

 been shown to spread chiefly in the direction of the slope of the 

 gutter, apparently because the liquid discharges from the vulva 

 had passed along the gutter and soiled the bedding of the suc- 

 ceeding cows. As in the mare, it seems quite certain that the 

 infection is readily transferred from one animal to another by 

 persons who are caring for the animals. Milkers may readily 

 carry the disease from one animal to another upon their hands, 

 thus transmitting it from udder to udder, from whence it may be 

 transferred to the vulva through the medium of the tail or by 

 other means which readily suggest themselves. 



Symptoms. The symptoms of infectious abortion in the cow 

 seem to be somewhat more pronounced than in other animals. 

 It occurs most frequently in animals 5 to 6 months pregnant, al- 

 though Bang records cases as early as 3 months and admits that 

 it may occur very near to the end of gestation and that, in some 

 cases, the diseased fetus may be born alive in a weakened state 

 and may either perish within a few days or recover and continue 

 to live. 



Nocard states that when the calves are prematurely born 

 alive, as a result of infectious abortion, they sometimes bawl 

 in a peculiar manner, which would suggest to one the howling of 

 a rabid dog. Nocard attributes this to involvement of the me- 

 dulla oblongata. He was possibly dealing with infectious diar- 

 rhea affecting the calf at the same time. 



There is some tendency to the appearance of the symptoms of 

 genital catarrh as the forerunner of abortion. The vaginal mu- 

 cosa becomes injected and the lips of the vulva somewhat swollen. 

 Bang regards the malady essentially as an insidious uterine 

 catarrh. Naturally the injection of the vulvar mucosa, accom- 

 panied by vaginal discharge, would follow. 



Whether the swelling of the vulva and discharge from the 

 genital tract are the effects of the death or serious disease of the 

 fetus and of the disease process taking place in the fetal mem- 

 branes, or whether they constitute a fundamental part of the dis- 

 ease itself, is not known. It has not been shown that the vulvar 

 tumefaction and discharge precede the death of the fetus. If the 

 swelling and discharge occur only after the . death of the fetus, 

 they should be regarded as the precursors of the expulsion of the 



