P. G.
PANDE
43
the result of a test of this nature, was obviously excluded. Several cases
of debility and diarrhoea showing no response to avian tuberculin were ulti-
mately diagnosed as Johne's disease on the basis of post-mortem examination.
The bowel-washing method of diagnosis was adopted in respect of animals
at all stages of the disease, but its use has been found of limited value in con-
firming the presence of the disease either in known positive reactors, or in
those non-reactors in which the clinical symptoms were fairly advanced. In
the present investigation the avian tuberculin test was adopted in respect
of all the animals in different centres of outbreak, but the bowel-washing
method could be followed only in respect of animals of the Government farms
and the jail dairies.
The animals included in the sphere of the present investigation were
derived from several sources, principally the Government cattle breeding and
agricultural farms and the jail dairies, municipalities and the local boards.
Besides, the tests were conducted on cattle of private owners on whose pre-
mises the disease was positively diagnosed in some of their own farm-bred
animals or those purchased from the Government farms. The animals of
certain tea estates and some villages where Government bulls were reported
to have died of Johne's disease were also subjected to the test on the assump-
tion that the infection might have been contracted by these animals.
At the Government farms and the jail dairies where valuable animals
were maintained for breeding and issue to different breeding centres in the
province, the tests were undertaken several times during the years 1933-37
(as shown in Table I) with the object of controlling its further spread.
In other localities where the Government farm bulls were issued, the tests
were performed with a view to ascertaining the extent to which the infection
had spread amongst the cattle of indigenous breed.
INVESTIGATION
A. Incidence on the basis of avian tuberculin test
1. Khanapara Farm.—This farm originally occupied an area of 197 acres
of land, but overstocking of the available pastures during the subsequent
years necessitated its expansion to 207.75 acres. The farm was originally
stocked with Bihari, Tharparkar and the local cattle, but in 1928 Sindhi
animals were placed there for breeding operations which resulted in the year
1933 in a large number of cross-bred animals based on the Sindhi and the local
breeds. From 1927 to 1931 the main troubles of the stock were stated to be
the intestinal parasitism, infectious bovine lymphangitis, Theileria mutans
infection and mastitis. Before Johne's disease was detected amongst animals
of this farm, they were known to have an extensive infestation with Mecis¬
tocirrus digitatus, a nematode worm which had, during the previous years,
caused the death of several calves and some adult cattle.
When the first case of Johne's disease was diagnosed in January 1933,
on autopsy of a Sindhi bull of this farm, it was naturally presumed that the
condition, although existing on the farm long before 1933, could not be clini-
cally diagnosed earlier due to almost identical clinical symptoms of mecisto¬
cirrosis occurring simultaneously amongst the farm animals. This presump-
tion was later substantiated by the fact that although periodical drenching