10     THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [I, I

                           16. PIROPLASMOSIS.

         The " piroplasmoses " are diseases caused by invasion of red blood cells with
numerous minute animal parasites (piroplasms). In natural circumstances they are
transmitted to animals by the bites of ticks, but they can also be transmitted
artificially from an infected animal or a " carrier " of the piroplasms, to a suscepti-
ble healthy animal. In this manner they may be injected inadvertently into the
inoculated cattle with the virulent blood. In many localities all the cattle become
infected naturally while they are young, by the bites of ticks. Young cattle possess
a high degree of resistance and recover readily, but they always harbour small
numbers of the parasites in a dormant state in their systems afterwards throughout
life. During even a mild attack of rinderpest the parasites may be roused again
from their dormant state owing to the depressed condition of the animal's body and
invade the system once more in large numbers. This awakening of the parasites
may take place at any time after inoculation of rinderpest virus and the disease
then seen is not due to any piroplasms that may have been present in the virulent
blood. This so-called " resuscitation " may therefore occur when the goat virus
method is used although that virus has been cleansed of piroplasms. (Chart 11).
There are two main diseases of cattle due to " piroplasms ".

         (a) Redwater. The parasites which produce this disease are known as Babesia
bigemina, which are relatively large bodies found within the red cells, often resem-
bling two-pears meeting towards their narrow ends, or else appearing in large round
forms resembling a signet ring. (Plate I, fig. 1). The reaction due to redwater or
ganisms often occurs on the sixth evening (charts 8 and 9). It may, however, occur
until about the tenth day, or sometimes a day or two later. The reaction consists
of a sharp rise in temperature usually much higher than that observed in rinderpest.
The two reactions may be superimposed, thus fever due to rinderpest may be
exhibited from the 3rd, 4th or 5th days and a further rise perhaps to 106 or 107°F.,
due to redwater may be seen on the 6th evening or later (charts 8 and 9). The
complicating disease is frequently associated with the characteristic clinical
symptoms of redwater, namely, the passing of urine coloured red or dark-brown
from the presence of destroyed blood excreted by the kindneys; sometimes,
however, the animal may die suddenly without exhibiting any such symptom.
(Chart 10). The resuscitated disease is similar except that it may occur either
earlier or later than when due to inoculation.

         A form of specific treatment is available for this disease, namely, the use of the
drug Trypanblue (Chart 8). Dissolve the powdered drug to form a one per cent.
solution in boiled water, and preferably filter the solution before use. It is highly
advantageous to inject the drug intravenously since its action is then more rapid