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23. When a pregnant cow has passed through an attack of rinderpest
without abortion or premature birth taking place at a later period brings forth
a living calf, will the offspring have received protection against rinderpest ?
The two animals utilized in this experiment were those used by Professor
Koch whilst demonstrating his methods at Muktesar. After recovery from
rinderpest they were respectively retained, with a view to determine the period
during which they would remain immune from the disease.
Plains cow, No. IV, aged 2 years and 6 months.—In calf about 72 days.
Rinderpest communicated on June 6th, 1897, by smearing nasal discharge from
a diseased animal in the nostrils of cow IV. On the 16th, the temperature
rose from 37.5°C. to 39.8°C. and remained at about 40°C. for 5 days, and then
fell. During this period the animal presented symptoms of rinderpest and
only finally recovered three weeks later. On 31st December 1897, a bull
calf was born, which suckled its mother for some months, and was then kept
apart. On 31st March 1899, the calf when 15 months old, was inoculated
subcutaneously with 10 c. c. of virulent blood from bull No. I, in order to
test whether the animal was protected against the disease. The morning
temperature was then 37.9°C., and on the evening of the 5th day rose to 40.4°C.
On the 3rd day of the disease (7th from inoculated) the temperature recorded
was 40.7°C., and then gradually fell, until on the morning of the 6th day, it
had fallen to 38.4°C. The animal was kept under observation for a further
period of 14 days, and as no symptoms of rinderpest had supervened, it was
segregated for a term and sent to the herd.
The reaction which followed the injection of a large dose of virulent
rinderpest blood was of a very slight character, proving that the offspring of
cow IV had received immunity "in utero" without the protection had been
acquired during the period of suckling, which although possible, the former
influence is the most probable.
Resumé—
Cow impregnated
Exposed to infection
Symptoms of fever
Bull calf born
.
.
.
.
.
.
.
.
.
.
.
.
Calf suckled and later kept apart
Tested with 10 c. c., virulent blood
.
.
.
.
.
.
beginning of April 1897.
6th June 1897.
16th June 1897, 72nd day of pregnancy.
31st December 1897.
year 1898.
31st March 1899. Age 15 months
(455 days), proved immune.
Plains cow, No. XIII.—In calf 40 days. On 14th June 1897, this animal
was inoculated with virulent rinderpest blood and bile in the proportion of 1
to 9, obtained from an animal which died on the 8th day of the disease.
Highest temperature 39.6°C. persisting 4 days, no symptoms of rinderpest.
Cow calf born on 2nd February 1898. Offspring suckled by mother for several
months. When 14 months old, the calf was exposed to natural infection (15th
April 1898). Temperature began to rise on the evening of the 4th day,
registered 41.3°C. on the 6th day, and 41.5°C. on the evening of the 9th day.
The temperature then gradually fell until the morning of 12th day and then
registered 38°C. Later made a rapid recovery.
The offspring of cow No. XIII passed through a slight attack of rinderpest
which lasted 6 days, for it was feeding well on the 13th day after the date of
exposure to the disease.
Result.—Animal had evidently received some protection "in utero," but
the effect was passing off. Most probably if the trial had been postponed for
a few months, the animal would have passed through or succumbed to a severe
attack of rinderpest.
Resumé— Cow impregnated
.
.
.
Inoculated, bile and virulent blood
Cow calf born .
.
.
Calf exposed to natural infection
.
.
.
.
.
.
beginning of May 1897.
14th June 1897, about 45th day of
pregnancy.
2nd February 1898.
15th April 1899, age about 438 days.
In continuation of this research and from the scientific point of view, the
following experiments are being arranged for :—
(i) To test the efficacy of the milk of a protected cow, with regard to
its immunizing effect upon a calf, the mother of which has not