MUKTESAR, FOR THE YEAR ENDING THE 31ST MARCH, 1928
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indigenous cattle (16.28 per cent.) found at Ferozepur and Lahore reported previously.
If the results are judged according to the standard recommended by McFadyean and
Sheather, 36 out of 67 or nearly 54 per cent. would be taken as reactors ; and in 11 out
of these reactors or nearly 30 per cent. definite tuberculous lesions were demonstrated.
Taking into consideration the fact that even a slight infection with tubercle bacilli which
may or may not produce a visible lesion is sufficient to give rise to a positive reaction to
tuberculin test and the difficulty of detecting on post-mortem examination in an animal
weighing 400 to 600 lb. a minute lesion which may be situated in any part of its body,
it may reasonably be assumed that the proportion of infected animals was in reality
greater than what has been possible definitely to demonstrate. The subject is of con-
siderable importance and is worthy of further exhaustive investigation.
Standardization of tuberculin. A method of standardization of tuberculin of unknown
potency was developed and it appeared to be simple and reliable.
The method consists in comparing the degree of reaction developing after intradermal
test with different dilutions of the unknown with the standard tuberculin performed on a
tuberculous bovine, either a bull or a buffalo, all injections for the test being done with
corresponding doses at the same time and in an identical manner. The reaction develop-
ing in the buffalo after the intradermal test is very often much more marked than in the
case of the bull. Several dilutions of the tuberculins are made and the test with each
dilution is made at a different spot preferably on the skin of the side of the neck at a
distance of a few inches. The maximum dilution of the sample under test which gives a
definitely positive reaction is then compared with a similar maximum dilution of the
standard tuberculin and further comparison is also made between the degrees of reac-
tion resulting from other dilutions. In a few preliminary tests made by this method it
was found to be more suitable than one in which guinea pigs are employed.
Some experiments were done with Calmette's B. C. G. on previously infected animals.
Nine animals previously infected with different types of bacilli were inoculated intra-
venously with 200 mg. of B. C. G. No untoward effect of this inoculation was noticed.
When test inoculations were made intravenously two months later with 5 mg. of virulent
bovine bacilli, 7 out of 9 animals died of acute generalized tuberculosis, 6 in 2 to 10 weeks
after inoculation and one after 8 months. In the case of these previously infected animals,
therefore, B. C. G. did not confer the same immunity as is said to be produced in unin-
fected animals."
(h) Contagious abortion. Work was continued on the common
specific contagious abortions of mares and cattle in India, and much
information has been added to our somewhat voluminous records on
these diseases. Vaccination as mentioned in preceding reports was under-
taken in certain studs and herds.
(i) Minor researches. These comprise, (i) standardization work
on mallein and tuberculin; (ii) further work on the pathogenic coccidia,
resuscitation of bovine coccidia with croton oil ; (iii) continued observa-
tions on the bovine piroplasms, with notably changes in morphology
of B. bigeminum during active proliferation in the course of acute infec-
tions, and some observations on the natural exaltation in virulence of
the common Theileria mutans; (iv) strangles, observations continued
at the Remount Depots ; (v) isolation of B. viscosum equi from equine
lesions closely resembling those of glanders; (vi) pleuro-pneumonia
of goats, studies of lung lesions, similarity with rinderpest in these
animals.
(j) Miscellaneous. The total number of post-mortem examinations
carried out at Muktesar was 1,529. The number of blood smears from
experimental and other animals examined at Muktesar was 3,416. The
number of specimens received from outside sources (excluding sera for
agglutination tests and blood smears) was 50; the number of blood