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The milk from affected cows was withdrawn from distribution although no alteration in quality could be observed. This action, taken by the management on their own initiative and maintained by them throughout, is eminently worthy of commendation since the gain to their clients meant a very serious loss to them and it is an open question whether the milk in such a disease would be injurious to the health of the human beings consuming it, but be that as it may, the public were given the benefit of the doubt.
From the symptoms it was concluded that the disease must be of a malarial type and accordingly quinine was given in the usual doses recommended by text books. This was found to have no effect.
Phenacetin and other antipyretics were also tried, but no effect was produced, about this time the true character of the disease was ascertained and it was decided to try the effects of larger doses of quinine. Accordingly doses up to 2 ounces per day were given, and an improvement began to be noticeable. Ultimately all the animals recovered perfectly except one; this animal, however, did not die of the dis- ease but of an intercurrent attack of pneumonia. There have been one or two relapses since, but so far only one or two animals were affected. Their condition never became serious, and the former heroic doses of quinine have not been resorted to. As is usual in all cases of cattle sickness, blood films were prepared according to the common technique. These were fixed sometimes by alcohol or stained without previous fixation. The tinctorial methods used were the following:- Methylene blue and eosin, fuchsin, polychrom methylene blue, and Leishman's modification of Romanowsky's method. A superficial microscopic examination of the films showed practically nothing.
There could be no question of a micro-oraganism like that found in Hæmor- rhagic Septicæmia or of pronounced Trypanosomiasis. On careful examination, however, our attention became directed to the presence in many of the red blood corpuscles of small faintly coloured bodies resembling at first sight the plasmodia of malaria. Repeated examination of the films, and the daily preparation of other films has convinced us that these small bodies lying in the red blood corpuscles are nothing less than a Pyroplasma.
Further details in regard to our investigations of this blood parasite and its significance will be given under a subsequent heading. As has already been men- tioned during the course of our recent investigations into different outbreaks of cattle disease, two entirely new pathogenic agents have been discovered in the tissues of cattle housed in the Colony, namely, the Trypanosoma and the Pyro- plasma. The finding of these two blood parasites is of great moment and immensely complicates the routine research into the Etiology and treatment of a disease like Septicemia. Not only so, but according to other investigators in the Southern States of America, Jamaica and Manila, these parasites constitute two of the greatest foes in cattle raising industry.
The following is a resumé of our researches into these parasites up to the date of writing.
The Trypanosoma. So far only one animal has been found suffering from Trypanosomiasis. As already mentioned, this animal was discovered to be infected with this parasite during an outbreak of cattle disease in the Kennedy Town Cattle Depôt in April, 1904.
At no time did this animal present any evidence of sickness. Its temperature was taken immediately on its admission to the Depot and, being found normal, the animal was housed in one of the sheds containing healthy bullocks.
A few days later, however, the animal was found lying dead. No post-mor- tem examination was made, but, in order to assist in arriving at a diagnosis as to the cause of death, blood films were made from the ear.
These were stained according to the usual methods and Trypanosomata were found present in enormous numbers in each blood film. Huge masses of the parasite were found agglomerated together producing an appearance like that de- scribed by SIVORI and LECKER in American Surra. The individual parasites were large in size resembling those described by THEILER in the Cattle of South Africa.