GRANULAR VENEREAL DISEASE AND ABORTION IN CATTLE. 51 
In one herd during a period of 10 years 61 heifers were bred on 
the premises for the first time, of which 3, or 5 per cent, failed to con- 
ceive and 58 became pregnant. Among the 58 heifers in first preg- 
nancy 21 animals, or 36 per cent, aborted or calved prematurely. 
Nine of the 21 aborting in first pregnancy did not conceive a second 
time. Ten, or 48 per cent, of the heifers aborting during first preg- 
nancy had reached, at the date of compilation, the termination of 
second pregnancy with two abortions (20 per cent). -Thirty- seven 
heifers calved from their first pregnancy, of which 25 (67 per cent) 
had terminated their second pregnancy at the date of compilation. 
Of these 25, 4 (16 per cent) aborted. 
One of the four heifers which calved from the first pregnancy and 
aborted from the second had retained placenta, which should be 
accepted as indicating that the abortion infection had then seriously 
invaded the pregnant uterus. Adding her to the first group of 10 
heifers which aborted during first pregnancy and conceived again, we 
have a total of 11, with 3 abortions, making 27 per cent of heifers 
aborting during first pregnancy and reaborting during second preg- 
nancy. If we deduct this heifer from the group calving normally 
from the first pregnancy and aborting during the second, the total 
is reduced to 24 animals, of which 3 (12 per cent) aborted. In other 
words, the vital statistics of this herd indicate that a heifer which has 
aborted or given birth to a premature calf or in which calving has 
been complicated by retained placenta is more than twice as liable 
to abort during her second pregnancy as is a heifer which has calved 
normally from her first pregnancy. 
The statement is frequently heard that after two abortions a 
marked immunity is acquired. Our data emphatically contradicts 
this. Few cows ever conceive after a second abortion. A large 
proportion of them succumb to metritis (placentitis with retained 
placenta), many fail to breed again, and many others are sold to the 
butcher or are otherwise excluded from the herd. 
Regarding premature birth and retained placenta as equivalents 
of abortion, 4 animals in the herd aborted twice or oftener. Of 
these 4 reaborters, one was sold after the second abortion, another was 
sterile for a year and then bred regularly, the third bred regularly 
for seven years. The fourth cow aborted her first pregnancy and 
had retained placenta, her second pregnancy resulted the same; she 
was sterile her third breeding year; gave a premature birth with 
retained placenta her fourth breeding year; and a calf and retained 
placenta and fetal metritis in her fifth breeding year. The common 
belief that abortion induces immunity to future abortions is one of 
the most unfortunate errors which has been allowed to creep into the 
question of abortion in cattle. One abortion predisposes to re- 
abortion, 
