48 REPORT OF THE IMPERIAL BACTERIOLOGICAL LABORATORY,
(k) Bovine Coccidiosis. A very exhaustive study of this condition,
was made during the years under report by Mr. Cooper. It is rather
extraordinary that the significance of this infection had not been appre-
ciated before in India, for examinations at the laboratory have shown
that nearly all cattle brought in from the vicinity are carriers of coccidia
in their alimentary tract. It is not unlikely from the information already
to hand that the infection is also widespread in the plains. The applica-
tion of the Sheather flotation method to the examination of faeces has
rendered relatively easy the detection of carriers, and the computation
of variations in the intensity of infection. The studies conducted at
the laboratory have been directed partly towards obtaining knowledge
in regard to the nature and life-history of the coccidia infecting cattle,
and also very notably towards obtaining precise information concerning
the relationship of a rinderpest infection to resuscitation in virulence of
the dormant coccidia. A striking phenomenon frequently observed in
following the course of clinical rinderpest is that the animals succumb,
not to the direct action of the rinderpest infection, but to a complicating
sequela manifested in the form of dysentery and exhaustion due to sudden
multiplication in large numbers of coccidia in the depressed intestinal
mucosa. Some observations were also made upon coccidiosis in other
animals.
(l) Piroplasmosis. The amount of precise information upon the
piroplasms of cattle in India that was available in the technical literature
was very small, considering how well these protozoan parasites had been
studied elsewhere in the world. It was surprising to find that in the
minds of veterinary workers the detection of any piroplasm in a blood
smear from an ox was taken to indicate infection with the causative
agent of tropical " red-water." At the laboratory the staff employed in
the routine examination of smears from cattle that showed febrile symp-
toms differentiated the intracorpuscular parasites discoverable into
"large" and "small" piroplasms, without giving any more exact
information concerning the nature of the bodies. In the organisation of
the examination of routine material for research information, the supervi-
sion of microscopic diagnosis of the blood films forthcoming daily was
entrusted mainly to Mr. Cooper, and a system of recording laid down,
whereby indications could be obtained as to the distribution and nature
of piroplasm-infection in cattle used at the laboratory; officers visiting
the laboratory for training were also made to take a share in this important
form of practical disease investigation. In the records of the year 1922-23,
there appeared among 4,325 smears examined positive evidence of infec-
tion in 504 smears, of which 80 were stated to be infected with a large
piroplasm (Piroplasma bigeminum) and 220 with "small piroplasms."
On investigation of representative smears infected with the latter type
it struck me that all the small parasites conformed exactly with the
descriptions given by authorities (the Sergents and others) of Theileria
mutans, The large piroplasm was undoubtedly Piroplasma (Babesia)
bigeminum. The conformation of these parasites was then displayed
clearly to the staffs entrusted with smear examination, with the result