S. N.
SAPRE
l5l
Further stress the importance of tick control
measures.
SUMMARY
Methods adopted for the control of acute the-
eriasis in calves due to Theileria annulata are
described.
Calves less than three months of age were the
most susceptible, mortality rate among such calves
between 1936 and 1939 ranging from 13 to 23
per cent. The vector of the disease is tick,
Hyalomma aegyptium.
Control measures consisted in keeping calves
weaned at birth in tick-proof paddocks for at least
three months.
The liberal use of tick-dip was practised both
for young calves and their mothers in order
to keep down the number of ticks in the
farm.
ACKNOWLEDGEMENTS
Our thanks are due to the farm authorities
for their hearty cooperation; to Mr Jalal Moham-
mad Khan, the then Deputy Superintendent of
Grantee Farms in the Punjab, and to Mr Wali
Mohammad Khan, M.R.C.V.S., the then Veteri-
nary Investigation Officer of that province, for
lending great assistance in carrying out our obser-
vations.
REFERENCES
Fotheringham, W. and Lewis, E. A. (1937). Parasitology
29, 504
Sen, S. K. and Sreenivasan, M. K. (1937). Indian J. vet.
Sci. 7, 16
TRANSMISSION OF PASTEURELLOSIS BY THE FLEAS (CTENOCEPHALIDES
FELIS)
By S. N. SAPRE, Imperial Veterinary Research Institute, Mukteswar
(Received for publication on 13 April 1944)
THE general association of pasteurellosis with
the seasonal flare-up of fleas has been stressed
by Mehra [1943] in an article presented to the
30th session of Indian Science Congress. Sen
[1925] suggested the possibility of fleas acting
as mechanical transmitters of haemorrhagic sep-
ticaemia because of the morphological resemblance
between the organism of human plague and that
of haemorrhagic septicaemia and also because fleas
are active agents in the transmission of the former
from rat to rat and from rat to man. Daubney,
Hudson and Roberts [1934] succeeded in trans-
-itting the disease experimentally from mouse
to mouse with Ctenocephalus felis. Mehra [1941],
while working at this Institute, found that the
disease could be transmitted from rabbit to
rabbit by this species of flea. The main object
of the present investigation has been (1) to confirm
the findings of previous workers as regards the
transmission of pasteurellosis by fleas in rabbits
and (2) to test the possibility of the disease being
reproduced in buffaloes through the agency of
these insects.
PASTEURELLOSIS IN RABBITS
Preliminary experiments were undertaken to
determine the course of bacteriaemia following
an artificial infection of rabbits with Pasteurella
septica, to find the best time for liberating fleas
on the infected animal, and to determine the most
suitable time for inoculating the donor rabbits.
While fever is usually a reliable index of bacteriæ-
mia, microscopical examination of suitably stained
blood smears would be a more positive proof.
Kraneveld and Djaenoedin [1928], working on
Pasteurella septica infection in buffaloes have
shown that rabbit inoculations arc often
positive when microscopical findings are
negative.
In order to determine the points at issue, three
adult rabbits were used. After ascertaining that
their temperatures were normal, they were in-
oculated subcutancously with 1.0 c.c. of a 24 hour
broth culture of a virulent strain of P. septica
(of bovine origin) at 10 -4 dilution. Blood cultures
were made at various intervals after inoculation,
and at the same time rectal temperatures were
recorded and blood smears stained by Leish-
man's method. For culture, 0.1 c.c. blood from
the ear vain was taken into 9.9 c.c. of Ringer
solution; from this, ten-fold serial dilutions were
plated in 5 per cent serum agar. Counts were
made after 24 hours at 37ºC. The results are
shown in Table I. Rabbits died from 14 to 18
hours after infection. Cultural and microscopical
examinations gave the following results: