6
Rinderpest Immunisation with Goat Virus
be expected in field immunisations and that the virus is far too virulent for
general use for our buffaloes without serum.
Table IV shows an attempt to arrive at the minimum dose of serum
necessary to protect buffaloes against goat virus. The serum used may be
described as convalescent serum, that is serum drawn after recovery, from
buffaloes injected simultaneously with buffalo virus and serum. No attempt
at hyperimmunisation is carried out in the production of this serum. This
table also illustrates the virulence of the virus for buffaloes and indicates
that serum at the rate of 1 c.c. per 3 kilos to 5 kilos body-weight (80 c.c. to
120 c.c. for a buffalo weighing 350 to 400 kilos, our average test animal)
was found necessary to control reactions adequately and that even with
this dosage some diarrhœa may occur.
THE INFECTIVITY OF ANIMALS AFTER INJECTION WITH GOAT VIRUS
As recorded in the introduction, several writers have stated that little
fear need be entertained that the use of live-goat virus will infect unprotected
animals or set up fresh centres of infection, by contact. We have therefore
endeavoured to obtain experimental evidence supporting or refuting such
statements.
We have demonstrated, by the inoculation of susceptible buffaloes,
that virus is present in the blood of animals between the fifth and fifteenth
days after the injection of goat virus, whether the animal shows an appre-
ciable reaction or not and also in animals partially protected by serum.
The period does not represent the end points of the presence of virus, no
attempt having been made to determine such dates. We have so proved
the presence of virus in the blood on nine occasions in buffaloes and on two
occasions in calves. The results are set out in Table V. Urine from two
buffaloes injected with goat virus has been tested on two occasions and in
both cases virus was absent. Virus was shown to be present in the blood of
the donor of the urine on the seventh day, the non-infective urine sample
being obtained on the ninth. In the other instance the urine was tested
on the tenth day with, as already stated, negative results but the blood was
not tested from this animal.
Nasal secretion has been tested from two calves of about one year old
with the following results. The animals were from an area subject to rinder-
pest but were reported never to have had the disease. They were injected
with a saline suspension of goat spleen. There was no appreciable reaction
in either case and when retested with virulent buffalo blood after an interval
of 39 days, there was again no reaction. On the seventh day following the
first injection of goat virus, the nasal cavities were washed out with sterile
saline and 40 c.c. of such washings were injected into susceptible buffaloes to
test for the presence of virus. Buffalo 486 which received 40 c.c. nasal wash-
ings from calf XX developed a typical rinderpest reaction, the temperature
rising to 103°F on the fifth day, diarrhœa occurring on the ninth day and
blood being present in the faeces on the eleventh day. The animal, however,
recovered. There appeared to be no doubt that virus was present in the
nasal secretion of calf XX. In the case of calf XXI, the result was not so