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THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [VII, IV
It would appear from Table I that six animals were treated with the fresh
stock of trypanblue and five with the old, leaving seven animals untreated to serve
as controls. In all cases treatment was instituted on the day the parasites were
detected in their blood after an incubation period of three to six days. On the
basis of M. T. D. tests carried out at the commencement of this work, all the animals
under treatment were given 30 c.c. of a 1 per cent solution of trypanblue per 25 lb.
body-weight intravenously. Goodall [ 1914 ] reported successful results with
heavy doses of trypanblue up to 250 c.c. of a 2 per cent solution intravenously for
cattle infected with B. bigemina and attributed failures to be due to small doses
being used. But our results did not support his views as in none of the eleven
cases so treated was the sterilization of the circulating blood obtained during the
post-treatment period of observation of twenty days.
The above series of experiments yielded almost conclusive evidence as to
the ineffectiveness of trypanblue to be regarded as a ' specific ' for the tropical
red-water parasites. Several eminent workers have used trypanblue extensively
in the treatment of bovine piroplasmosis due to B. bigemina infection doubtless
with amelioration of the symptoms but, in several instances their records either
do not show that the diagnosis was based on microscopical examination, or that
the cures were established on examination of blood films after the treatment.
Thus, Mellis [ 1914 ] reported to have treated twenty-three cases with trypanblue
in North Africa on clinical manifestations and obtained nineteen recoveries.
In the four cases that died the drug was stated to have been given subcutaneously.
Goodall [ 1914 ] reported to have treated hundreds of cases with large doses of
trypanblue but the effect of the drug was not determined by microscopical exa-
mination. Yakimoff and collaborators [1917] used 25 c.c. of a 1 per cent solution
in normal saline giving a total of 2—3 grm. in acute cases. While stating that the
cures were ' complete ', the authors do not bear out this on blood smear examina¬
nation.
The possibility of the strain having acquired drugfastness was also ruled
out as a result of similar tests being carried out with an untreated strain of
B. bigemina obtained from the field. For the purpose of this work seventeen healthy
animals were artificially infected with the field strain. Five of these were treated
with the old stock of trypanblue and six with the fresh, leaving six to serve as con-
trols. Only one animal proved refractory to the infection. The treatment was
carried out under identical conditions as in the case of the first lot of the labora-
tory strain of B. bigemina, employing the same dose rates of the two stocks. The
results obtained in this case could lend no support to the presumption that the un-
treated strain of the parasites was amenable to treatment with either brands of try-
panblue. On consideration of the results, the use of trypanblue had, therefore,
to be discontinued. Recently, Theiler [ 1930 ] expressed the view that since the
war substances called trypanblue have been produced but they are devoid of para¬
siticidal action.