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Contagious Abortion of Cattle, Sheep and Goats [VOL. XVIII, PART III
A study of the detailed survey suggests that, as far as farms are concerned, Brucellosis is most
prevalent where farms are abundant, but there is some evidence to suggest that, provided there is
a sufficient reservoir of infection, epidemics and endemics in farms are gravest where rainfall is either
very heavy, as in the coastal belt of Bombay and in Assam, or, to a lesser degree, in the bi-seasonal
or tri-seasonal rainfall areas, such as the Himalayan water-shed, east of Meerut, Ambala and Lahore.
As for infection in village stock, inspection of Table I reveals a curious and interesting posi-
tion. Infection, as far as it has been discovered, lies mainly in the tri-seasonal rainfall area of the
peninsula south-east of the red line, Fig. 12. It has, however, advanced as far as, and follows with
considerable accuracy the limits of the bi-seasonal rainfall area (south-east of the blue line, Fig. 12).
Conversely, the area of minimum village infection seems to be the arid north-west. But, although,
throughout these epidemiological studies, it is necessary to bear in mind the fundamental function
of climate, its precise role can only be postulated when all other considerations have been brought
into account.
A DETAILED SURVEY OF BRUCELLOSIS IN INDIA BY CLIMATIC REGIONS
Region 1. Sind, Baluchistan, North-West Frontier Province, Rajputana and Ajmer
This region consists of the Thar desert, the partially irrigated lower Indus valley and the arid
hills of the north-west; the mean annual rainfall is the least in India.
Village stock. In this region, village Brucellosis seems to be rare or absent. Thus enquiries
by the Veterinary Investigation Officers of Sind and the North-West Frontier Province and the
writer elicited the invariable reply that village abortions occurred with extreme rarity. Again
random tests at Peshawar, Karachi and in the Rajputana States showed a few doubtful or weakly
positive reactors. Abortion in sheep and goats, on the other hand, is relatively common, but all
tests on these animals have been negative to Brucellosis and the mishap can usually be attributed to
other causes (page 189).
Farm stock. In the few organized farms of these parts, clinical abortions and Brucella reactors
are either absent—as in the indigenous herds of Government or private farms; or present in a small
degree—as in the cross-bred herds of the military farms scattered along the north-western foot-hills
from Quetta to Peshawar. Apart from an occasional superimposed epidemic, the infection in these
farms is endemic and the abortion rate is estimated to be less than 2 per cent per annum.
Region 2. The Punjab and the United Provinces
The major portion of this region is cultivated. The rainfall is moderate (40 in.) on the north-
east, but decreases towards the west and south, where desert conditions tend to link up with region
(1). In these southern and western tracts the rainfall is less than 2 in. with the exception of the
period from June to October. Except on the Himalayan foot-hills, deep forest is rare.
Village stock. Apart from certain serious and anomalous epidemics in buffaloes, which are
fully described on page 188 both clinical abortions and Brucella reactors are rare amongst village
cattle. Enquiries in villages tend to put the rate of clinical abortion in cows at 1 per cent per annum
or less, while random blood samples collected from slaughter-houses at Rohtak, Lahore, Meerut and
Bareilly reveal a few doubtful and weakly positive reactors. For example, of 35 buffaloes bled at
Rohtak none was positive; and of 292 buffaloes tested at Meerut, 10 (3.4 per cent) were doubtful
reactors and three were weakly positive, whilst at Bareilly of 53 tests on cows and buffaloes two
gave doubtful reactions. Goat and sheep abortion, however, is fairly common, especially in the semi-
desert tracts of the west, but, here again, tests have always been Brucella negative and the condition
is usually attributable to other causes.
Farm stock 1—Indigenous. In the indigenous herds of military, Government and private farms
of the semi-desert tracts of the south-western Punjab, Brucella reactors are either present in small
numbers (5-15 per cent of the herd), or were at one time present and have since died out. In the
former farms, the abortion rate is about 1 per cent per annum and in the latter, although at one time
it was as much as 7 per cent per annum, the rate is at present negligible. In the indigenous herds
of the United Provinces, Brucella reactors are few (viz., about 5 per cent) and clinical abortions occur
at the rate of less than 1 per cent a year; moreover, exacerbations have not been reported during