256
Streptococcus Mastitis in Buffaloes
sometimes in salicin, but not as a rule in mannitol
or sorbitol.
General incidence
Before any policy concerning mastitis could be
suggested, it was necessary to be convinced that
the disease was in fact widespread and of importance.
Between May and October, 1944, a preliminary
survey was therefore undertaken on three different
farms; during the same period, another laboratory
working in cooperation with us undertook the
examination of two more farms.* The results are
recorded in Table I from which it may. be seen that
the incidence of infection varied from 13.1 to 18.5
per cent, and that of the total number of 3,322
animals examined 16.0 per cent were infected.
Since the original survey, other examinations have
been carried out on some of these farms and the
results have confirmed the finding of a fairly high
incidence of infection.
The indications were therefore that streptococcus
mastitis was fairly widespread and it was to be
assumed that it was the cause of considerable
economic loss.
TABLE I
Incidence of streptococcus mastitis in buffaloes
in Lahore area.
Farm No.
1
2
3
4
5
TOTAL
Number examined
511
1006
625
694
486
3322
Positive
93 (18.2 per cent)
168 (16.7 per cent)
90 (14.4 per cent)
91 (13.1 per cent)
90 (18.5 per cent)
532 (16.0 per cent)
Possible intermittency of excretion of streptococci
The original estimate of approximately 16.0
per cent infection was based on the results of one
test only. A point of considerable importance
however in dealing with this disease is the fact that
there is in buffaloes an apparent intermittency of
excretion of streptococci. This is shown in Table
II. Of the 730 animals examined, twice, with an
interval of about three months between tests, 122
were positive at the first test and of these only 60
(49.2 per cent) were positive at the second test.
Similarly of the 608 negative at the first test 106
were positive at the second.
TABLE II
Apparent intermittency of excretion of streptococci
at consecutive tests
—
First test
Positive.
Negative .
TOTAL .
Second test
Positive
60
106
166
Negative
62
502
564
TOTAL
122
608
730
This point needs more thorough examination.
It may indicate limitations of technique; it may be
due to contaminants preventing growth of strep-
tococci, or there may be a true intermittency of
excretion. In the meantime it may be said that
our figures do not suggest any relationship between
intermittency of excretion and. age or period of
lactation.
Association of mastitis with age
In general it has been the finding in cattle that
the older the animal the more likely it is to have
mastitis. This would seem a reasonable a priori
hypothesis; other factors being equal there must be
an increasing incidence with increasing exposure.
That this is also the case in buffaloes is shown by
the results recorded in Table III. From this table
it may be seen that the percentage of positive
animals increases from 12.5 among animals 4 to
6 years old up to 30 among animals over 11 years old.
TABLE III
Increase of mastitis with advancing age
Age in years
4-6
7
8
9
10
11
12 and over
Number of
animals
examined
24
83
202
258
249
157
60
Percentage
infected
12.5
13.3
19.8
20.2
23.7
25.5
30.0
* For permission to publish the results from Farms 4 and
5 we are indebted to Mr Abdul Qayum Khan of the Dairy
Bacteriology Laboratory, Lahore.