It has been aimed to present information on the
bacterial flora of normal genital tracts, and
bacteriology and pathology of endometritis in cows.
1. survey of the bacterial flora of 100 normal
non -pregnant and 31 normal pregnant genital tracts of
dairy cows is reported. 45 per cent of non -pregnant
and 32.2 per cent of pregnant genital tracts contained
bacteria. The incidence of bacteria in the cervix
uteri was 41 %; corpus uteri 9%; right uterine cornu
20%; left uterine cornu 9'/:.; and Fallopian tubes 2 %. These results indicate that under normal conditions
bacteria traverse the cervix up the uterus and a healthy cervix acts as a barrier against infection.
2. There was similarity between the bacterial
flora of the non- pregnant and pregnant uteri; and
also between that of the uterochorionic space and
3. iiicrococci (15,) were the commonest bacteria
in the genital tracts of non -pregnant cows, the next
in order were corynebacteria (16%); staphylococci
(15;;:x); coliform bacilli (y-); streptococci (W;
Gram positive aerobic sporing rods (3:-); sarcinae
(1%) and hlcaligenes faecalis (1%).
4. Neither Corynebacterium pyogenes nor Brucella
abortus nor mastitis groups of streptococci (Lancefie
group B. and Minett's groups 11 and 111) were isolate
from the normal genital tracts.
5. One hundred abnormal genital tracts were
examined for their bacterial contents and pathological
changes; 93 had endometritis associated ,viith cervicit
(32%) and salpingitis (25.3%), five primary cervicitis
and two salpingitis only.
6. The bacterial flora of abnormal genital tract
differed significantly from that of normal tracts.
Corynebacteria were the largest group (51%); the
next in order were staphylococci (33%), coliform
bacilli (14%, streptococci (12%), micrococci (10%),
Klebsiella oneumoniae (4%), Proteus vulgaris (3%)
Mycobacteriumtuberculosis (2%), Bacillus mesentericus
(2%) and Pseudomonas aeruginosa (1%).
7. The folloing bacteria were isolated from the
only abnormal genital tracts)- Corynebacterium pyogenes,
Corynebacterium equi, Staphylococcus aureus (with one
exception where it was isolated from a normal cervix)
Klebsiella oneumoniae, streptococci of Lancefield's
groups C. and G., Proteus vulgaris, Pseudomonäs
aeruginosa and Mycobacterium tuberculosis. Further,
the incidence of Staphylococcus albus was increased
to 25% in the pathological tracts as compared with
9.1% in the normal, the respective figures for
Escherichia coli were 14% and 7.6% and Corynebacterium
bovis 5% and 1.5%.
8. There was correlation between the type of
endcmetritis and the bacteria present in the uteri.
Staphylococci, «lebsiella pneumoniae, Proteus vularis,
coliform bacilli, streptococci and Pseudomonas aeruo.in psa
were associated with catarrhal endometritis, whereas
Corynebacterium pyogenes, Corynebacterium bovis and
Corynebacterium equi in pure or mixed cultures were
found in suppurative endometritis.
9. Corynebacterium nyogenes is considered the
most important single factor in the causation of
.suppurative endometritis since it was isolated from
86% of such cases. Staphylococci were mostly
associated with catarrhal endometritis and isolated
from 50% of such cases. A new variety of coryne-
:bacterium has been isolated and described. Tentatively
it has been designated Corynebacterium bovis var metritis.
10. Trichomonas foetus was recorded in three
cases of catarrhal endometritis. The cows from which
these uteri were obtained belonged to three different
farms in Ayrshire.
11. a. Five main types of endometritis were
distinguished according to the pathological changes
present viz., catarrhal endometritis (34.4%); suppurat
endometritis (38.7%); atrophic endometritis (12.9%);
tuberculous endometritis (2.1%) and hyperplast is
12. a. The lesions observed in diffrent cases
of catarrhal endometritis were ,primarily those of
catrrhal inflammation of endometrium with epithelial
degeneration, s_quamous metaplasia and degeneration of
glandular epithelium. These changes may be regarded
result of infections of a mild character,
in the case of staphylococci and Trichomonas
the structural alterations were pronounced.
b. In striking contrast to the above,
suppurative endometritis was characterised by extensiv
necrosis of endometrium including sloughing of cotyledons;
and usually involved all layers of the uterine wall,
periuterine structures and Fallopian tubes. Persistait
corpus luteun was a constant feature of well established
cases of pyometra. In the acute and chronic cases th
damage to the functional structures of the uterus was
so great that it is doubtful if they ever would have
regained their normal function. In sub -acute cases
the lesions were mainly confined to cotyledons. Since
this sub -acute stage is not easily diagnosable clinically, bacteriological examination of uterine swabs
c. The prominent structural changes in
atrophic endometritis were extensive necrosis and
atrophy mucosa, contraction of interstitial tissue
and intimal thickening of the arterial walls. Such
changes may be regarded as the late result of acute
inflammation where there had been extensive destruction of the endometrium.
d. Hyperplastic endometritis was characterised
by hyperplasia of endometrium and its glands whose
cystic dilatation was a prominent feature. It was
invariably associated with cystic ovaries. This type
of endometritis probably represents a hormonal disturbance, the cause of which remains ohscure.
13. The pathogenicity of Corynebacterium oyogenes,
Corynebacterium equi and Staphylococcus albus all
isolated from bovine endometritis was tested upon
ligated uterine cornua of guinea pigs. A study of the
progress of the lesions at various stages of infection
bowed that Corynebacterium pyogenes and Staphylococcus
albus gave rise to typical lesions comparable to those
met with in natural cases of endometritis in cows.
Fifty-two photographs illustrating the normal and
abnormal uteri are included.
14. The pH of normal uterine fluid averaged
7.08; amniotic fluid 7.22; the pathological exudate
in catarrhal endometritis averaged 7.50; suppurative
endometritis 7.61; atrophic endometritis 7.48 and
hyperplastic endometritis 7.01.
15. The significance of endometritis in relation
to bacteria, ovarian abnormalities and sterility is