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Canine piroplasmosis.—Last December the hounds of the Madras Hunt became
[illegible]ill and the Hon'ble Mr. Horne, C.C.S., Hunt Master, applied to the Institute in order
to ascertain the nature of their disease. The examination of the blood of the sick
animals has resulted in the discovery of a new pathogenic piroplasm of considerable
' interest. It was conjectured that the hounds probably acquired the parasite from
the familiar jackal (Canis aureus) which is regularly hunted in the suburbs of
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Madras. I was fortunate in being able to shoot a jackal in broad daylight and in
its blood the identical piroplasm which was first found in the blood of the sick
hounds was at once discovered. The blood of this jackal was inoculated into three
bazaar dogs, two of which had had a recent attack of Piroplasma canis. The three
dogs showed this new piroplasm in their blood after an incubation period of 15 to
16 days. A number of other dogs were inoculated with the blood of a hound and
four of these have also become infected, one of which died of the disease after 23
;. -days.
The parasite is commonly seen in the blood of an infected dog as a small ring
either with a large single mass of chromatin or two masses, one of which is much
smaller. It may be pyriform or oval in shape and some forms are seen to be
amæboid. It is about half the size of P iroplasma canis and its protoplasm is much
less voluminous ; the typical double pear-shaped bodies so characteristic of the
. common piroplasm of the dog are rarely seen. The disease is much more chronic,
:- slow in onset, causes extreme anæmia, enlargement of the spleen and liver and
great emaciation. In bazaar dogs fever is not a marked accompaniment, but in the
hounds the temperature frequently rose to 106° F. Trypanblau has no effect on
this parasite.
For this new piroplasm of the jackal I propose the name Piroplasma Gibsoni
in honour of Dr. Gibson who first saw it. The complete description of it and
, the disease it produces will be published in due course.
A few of the hounds were also found to be infected with a trypanosome probably
;I : Tr ypanosom I Evansi. This organism is also being studied in dogs and its method
e• transmission will, it is hoped, be found in time. A new Hæmogregarine has
been found in the blood of the jackal ; its asexual multiplication was found to take
place in the spleen as well as in the bone marrow.
In a smear from the spleen of a dog which died of fits in the Saidapet veteri-
nary Hospital, a species of coccidium was discovered. The occurrence of the
parasite in the spleen is unusual as up till the present Coccidium bigeminum is
only known from the intestine of the dog (Raillet and Lucet). Two new species
:,, . of Theileria have been found, one in the blood of the Indian mongoose (Herpestes
mungo), and the other in the blood of the spotted deer ( Cervus axis).
Insect Flagellates.—The study of these flagellates is being continued and at
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4 present Herpetomonas muscd domesticæ in the alimentary tract of Musca nebulo
! - is engaging ray attention.
Till recently the only method available for studying these parasites was by
examining those insects that were already infected and therefore it was impossible
to say what particular stage of their life cycle the parasites were in at the time of
the examination. By this method the life histories of the parasites cannot be
completely studied, nor can the exact way infection is acquired be ascertained. I
have been able to overcome these difficulties by breeding Musca nebulo, and then
'1 finding out how it becomes infected in nature. A number of experiments were
carried out with bred flies by allowing them to feed on meat on which bazaar
5, flies had already fed, and it was found that they ingested the flagellated forms of
r
.; Herpetomonas muscæ domesticæ. Further by keeping hatched flies in suitable cages
it has been possible to follow on each successive day the changes the parasities
, undergo. These experiments have opened up an entirely new field of research.
tH
!, ,. which has many practical bearings. It will, I have little doubt, throw much light
: on those flagellates which are known to occur in blood-sucking insects. At
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'• present no serious attempt has been made by any observer to find out how
blood-sucking insects acquire these flagellates, and consequently much confusion
has has arisen as to their true nature. I hope later to be able to carry out some
r•experiments with a species of stomoxys, which is infected with a Herpetomonas
and also with Tabanus striatus which is infected with Crithidia tabani (Patton).
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