14 ANNUAL REPORT OF THE IMPL. INST. OF VETY. RESEARCH,
This is a strong argument in favour of the wholesale introduction
of the " serum-simultaneous" method of immunisation of cattle in
India, since it can easily be understood from the results of this experi-
ment that control of rinderpest by " serum-alone " must at best be a
very prolonged and therefore tedious and expensive procedure.
(4) Irregular temperature reactions.—A number of observations'
including experimental sub-inoculations, were made with the assistance
of Mr. P. C. Banerji and Mr. Balwant Singh during the year where,
in the course of reactions to rinderpest virus injections, susceptible
animals showed distinct irregularities in the resulting temperature
curves.
(a) In a number of cases it was noticed that both in hill bulls and
goats used for rinderpest virus making, the temperature rose sharply
as soon as 48 hours after virus injection, whereas the normal incuba-
tion period has been found at Muktesar to be regularly three or four
days. On several occasions sub-inoculation of blood drawn from such
hill bulls and goats at the 48th hour proved that the virus was fully
infective, and on a few occasions it was noticed that the resulting
temperature reactions in the sub-inoculated animals again occurred at
48th hour.
(b) Information of interest resulted from some sub-inoculations
made during the course of routine anti-rinderpest serum testing, where
a few hill bulls exhibited marked hyperpyrexia. In these cases the
temperature rose to as high as 106 or 107° F. between the fourth and
sixth days after virus (and serum) injection, whereas in uncomplicated
rinderpest such high fever is not usually exhibited. Sub-inoculation
of blood from them. was made into hill bulls which received simul¬
taneously a dose of anti-rinderpest serum calculated to " block-out" a
rinderpest reaction. If the hyperpyrexia was due to some complicating
factor and not rinderpest alone, it was expected that the complicating
infection would reveal itself in these bulls. Actually a mild tempera-
ture reaction was exhibited in them, but on sub-inoculation again into
fully susceptible cattle only typical rinderpest resulted.
(c) In the course of this work rinderpest infection was actually trans-
mitted on four occasions through animals which had received serum
sufficient to protect them from death, and in one series the virus was
passaged through two animals in series where both had received serum,
and it was still sufficiently virulent to kill healthy hill bulls at the
third passage. In two of the serumized bulls from which sub-inocula-
tions were made the reaction in them had been very mild indeed; in
fact the type of almost " blocked-out" reaction that is looked upon as
ideal in the course of serum-simultaneous inoculation. This experimental
evidence proves that animals undergoing serum-simultaneous inoculation
in the field must, therefore, be considered infective, and segregation
measures cannot be neglected.
(5) Susceptibility of "plains" cattle.—As a result of experience
gained from extensive serum-simultaneous inoculations using goat virus
on average " plains " cattle in Bengal, Mr. P. J. Kerr, Director, Civil
Veterinary Department, Bengal, consulted us concerning the possibility