I.

                                                  HORSE SURRA.

A.—Recent outbreaks of Surra in fresh Localities.

Katgodam, N. W. Provinces (elevation 1,900 feet). Before 1890, many tonga
ponies (principally Cábulis) succumbed to Surra. Forty also died in 1890, and
fifteen between 1891 and 1893. The disease occurs during the rains, first at
the Katgodam stables, and later at the stables of the first stage (Bhugia-ghát,
elevation 2,500 feet), but never above the latter. At first the supposed cause
was contaminated water; but although 'pure water has been supplied since the
early part of 1892, the outbreaks continue yearly, Careful observations in
February 1894 revealed the presence of rat excrement in some quantity in the
grain stored for future use.

2.    In 1893, an outbreak occurred in the stables of the Dák ponies running
between Sâháránpore and Mussoorie. (Rayment.)

3.    In the same year, a horse arrived in the Port of Bombay from the
Persian Gulf, suffering from Surra. (Mills.)

4.    In Burmah (1893), the Kachis lost 14 elephants from the disease, out
of a total of 32, used for timber-drawing. (G, H. Evans.)

5.  Other outbreaks have occurred, one in Sind, among the horses of the Pre-
ventive Force (Police Report), and others, details of which have not been received.

B.—Treatment of Horse Surra.

Since the publication of the last Report, the experimental treatment has
been continued with success, the hitherto fatal disease having now proved amen-
able to certain drugs. The following is an outline of the case.

2.    The animal contracted Surra by gastric ingestion of soiled Mood,
after a latent period of 6 days, Treatment was commenced at once, consisting
of Arsenic as Liq. Arsenicalis, in gr. iv. doses, increasing rapidly to 12 grs.
daily. After a paroxysm of 5 days, during which time the hæmatozoon was
very numerous, it disappeared from the blood, The arsenical treatment was
continued for 65 days, 454 grs." of Arsenic being administered. At this
period the animal showed an aversion to the Arsenic in this form, For this
reason, and as previous experience pointed to the fact that Arsenic by itself did
not, in some cases, destroy the resting or immature form of the hæmatozoon,
the double Iodide of Arsenic and Mercury was substituted, as it was known that
the Iodide of Mercury does not form an albuminate, and consequently the whole
of the salt would be available. The Iodides "were continued for a period of
106 days, in order to ensure the absolute destruction of the immature form. In
all, 1822.75 c.c, or 288 grains each of the Tri-iodide of Arsenic and
Bin-iodide of Mercury, were given. Since the medicine was discontinued, about
8 weeks have elapsed; and the animal is in good health and condition; and no
hæmatozoon has appeared in the circulation for 423 days, or over 7 months,
For six and a half months during this period, the animal has averaged 4½
miles walking exercise daily. As it did not thrive on gram, barley (boiled) was
given in its place, with the most satisfactory results, the animal rapidly putting
on flesh.

3.    An experiment was made with the Alkaloid of Adhatoda Vasica,
" Vasicine," which was observed microscopically to have a certain effect upon
the. Surra hæmatozoon. Twenty-two (22) grains of the freshly prepared Alka-
loid in distilled water were injected directly into the blood stream of a horse
during the presence (numerous) of the hæmatozoon in the circulation. But
although numerous examinations of the blood were made for some hours after
the injection, the organism was apparently not affected.

4.    Observations have been made to determine the efficacy of subjecting
healthy animals to drugs, sufficient to cause the full physiological effects, pre-
vious to submitting them to experimental inoculation with Surra :

(i) By subcutaneous inpculation with soiled blood.

                    B 678—1