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out to Haig in Persia, which he was told was invariably fatal, the cause
of which the natives ascribed to the animals drinking impure water.
On Haig's return to India he became acquainted with surra, and then
recognised that the Persian animals were affected with all the outward
ymptoms of that disease. There are reasons for believing that animals
have succumbed to this disease in Abyssinia, and probably also in Southern
Europe, Nroth America, Brazil, East Africa, and Australia.

Further information is wanted under this head.

Symptoms of naturally-contracted Surra.—Horse. The invasion
of this disease is usually marked by symptoms of a trivial character,
those of a slight attack of fever being the only ones noted. It may
occasionally happen that the fever may be accompanied or even preceded
by local or general urticarial eruption. If the blood be examined micro-
scopically during the period of fever, it will present a normal appearance
as regards the disposition of the corpuscles, etc., but certain rapidly-
moving organisms will be found, which induce in the corpuscles a peculiar
vibrating movement, which if once observed will not be readily for-
gotten.

If no microscopical examination is made, and the patient is treated with
febrifuges, it apparently regains its health. After an interval of a few
days during which the infusorian in its mature form is not present in the
blood, the animal again becomes ill, and on examination well-marked
symptoms are found; the skin is hot, the temperature more or less ele-
vated; the pulse is full and frequent, 54 to 64 beats per minute; the con-
junctival membranes, especially those covering the membrana nictitans,
are usually the seat of dark-red patches of ecchymosis, varying in size.
The thirst may be slightly increased and the appetite somewhat dis-
turbed. At the same time slight catarrhal symptoms, including lachry-
mation and a slight mucous discharge from the nostrils, may be present.
The submaxillary glands may, at this period, be slightly enlarged and
tender on pressure. At this stage some swelling and œdema of the
extremities, generally from the fetlocks to the hocks, which pits, but is
not painful on pressure, makes its appearance. This swelling gradually
increases in size, and invades at a later stage the sheath and under-surfaces
of the abdomen and chest.

If the blood be examined microscopically during the second paroxysm
of fever, the infusorian will be discovered. Following this second
paroxysm we have a period of apyrexia during which the infusorian in
its mature form is absent from the blood, also the intensity of the
symptoms is abated and the animal has a brighter appearance; the
temperature falls occasionally to normal. During the period of apyrexia
the ecchymoses gradually fade out; the pulse becomes weaker and
thready, but the appetite is excellent. In some cases the amelioration is