GRANULAR VENEREAL DISEASE AND ABORTION IN CATTLE. 17 
severe that it has attracted the attention of owners or veterinarians. 
If abortion is not playing havoc in a herd, the granular venereal 
disease may not be seen. No effort is made to see it. As soon as a 
large proportion of the cows begin to abort and an explanation is de- 
sired, search may be made for the granular venereal disease, and at 
once it is declared to have broken out, but all the time it was there. 
So with abortion itself. In small herds an actually visible abortion 
may not occur for years, or occur so rarely that the owner forgets the 
fact and he is ready to stalS that his herd has long been abortion-free. 
In large herds, however, of 50 to 100 cows and over abortion is recog- 
nized as being essentially universal. Of course its contagiousness is 
often denied and a plausible explanation for the accident is given. 
The heifer (nearly always a heifer) has drunk too much cold water, 
has slipped and fallen, has been gored or kicked, crowded in a door, 
or suffered from some error in feeding, or from other causes too 
numerous to mention and to which all cows are inevitably subjected. 
Contagious abortion is too often confounded with the death and 
expulsion of the immature fetus. It is not at all essential that a 
pregnant cow affected with contagious abortion must abort or that a 
fetus affected with the malady shall die. It is no proof that the in- 
fection or disease of contagious abortion is absent from a herd when 
no dead fetuses are expelled, and it is far from proof that the con- 
tagion is absent when but one or two animals in a dairy of 25 to 40 
cows abort in a given year. We would better define contagious 
abortion of cattle as a chronic infection of the genital tract which 
may imperil the health or life of the fetus. The affection has been 
all too scantily investigated to permit of a conclusion as to what per- 
centage of pregnant cows having in their genital tracts the organism 
of contagious abortion actually abort. It is with certainty known 
that many of them do not abort. It is not at all rare to see cows giving 
birth to living, apparently healthy calves at full term, though atthe 
commencement of labor they expel large volumes of typical abortion 
exudate. A yet more familiar example is premature births, essen- 
tially all of which may be referred to the infection of contagious 
abortion. The infection may reside in any part of the genital tract, 
so far as now known, but can affect the fetus unfavorably only when 
within the uterine cavity. Even within this cavity it does not neces- 
sarily destroy the life of the fetus or even cause premature birth, but 
the birth may be apparently normal and the calf well developed and 
vigorous. 
Our entire view of the differentiation between accidental and con- 
tagious abortion needs revision. The belief in frequent accidental 
abortion in the cow is so deep-rooted in the minds of veterinarians 
and cattle breeders that the question is one difficult of approach. 
43378°— 14 3 
