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Horse No. XXXIII—An
urticarial eruption appeared forty-eight hours
after the hæmatozoon was discovered in the blood for the first time. It was
especially well-marked on each side of the neck, shoulders, flanks and rump. The
skin presented very numerous raised patches, varying in size from 1" to 3" X 1.5".
These lie densely covering the skin, and are circular or oval in form ; they
are particularly large over the skin extending from the angle of the jaw, along
the course of the trachea to the root of the neck. On the rump and flanks
the patches are smaller, averaging from ½" to ¾". The skin round the eyes is
œdematous, especially the lower lids. After persisting for twelve hours the
eruption commenced to fade. The temperature was subnormal, and the hæma-
tozoa few, during this period.
Horse No. L.—The urticarial eruption appeared on both sides of the neck,
forty-eight hours after the first appearance of hæmatozoon in the blood. The
individual patches were oval inform, and raised above the surrounding skin.
On manipulation the small raised patches appeared to be distended with jelly-
like material. The evening previous to the appearance of the eruption, the
temperature registered 41°C. and the hæmatozoa were very numerous, the
former suddenly fell over 3°C. and the hæmatozoon disappeared from the blood.
In this case there is no doubt as to the locality of the organism after leaving the
blood : it must have collected in the skin, and have been the cause of the rash,
as the hæmatozoon was found on microscopical examination of the exudation
from one of the urticarial wheals.
If we further examine as to the dates on which the eruption occurred in
the different cases, we find that in the naturally contracted ones, (Horses
Nos. LXV and LXXIII,) it occurred on the first day of the disease, and was of
the form known as " urticaria evanida "; in Horse No. LXXI it appeared on the
16th day, and was an urticaria ephemera, that in Horse No. III on the 18th day
was an U. ephemera also, and in Horse No. LXXII on the 22nd day, U. evanida.
In Horse No. XX, which acquired the disease by gastric ingestion, it appeared
on the 9th day of the disease, and was an U. ephemera.. In the horses
Nos. XXII and VI, it appeared in the former on the 11th, and in the latter on
the 12th day of the disease, both U. ephemera; and in the animals inoculated
with the blood of the horses through the goat,
In No. XLI the eruption appeared in 18 hours after inoculation,—
(U. evanida.)
In No. XL the eruption appeared in 68 hours after inoculation,.— (U.
evanida.)
In No. XXX the eruption appeared in 45 hours after the appearance of
the hæmatozoon in the blood,—(U. ephemera.)
In No. L the eruption appeared in 48 hours after the appearance of the
hæmatozoon in the blood,—(U. ephemera.)
Consequently it will be seen that the eruption of urticaria may take place
at any time, from 18 hours after inoculation, until the 22nd day after the appear-
ance of the hæmatozoon in the blood.
(2) Swelling and œdema at the seat of inoculation in experimental cases.—
When an animal has been subcutaneously inoculated with the soiled blood,
or other fluids containing the ' materies morbi ' of ' Surra, ' considerable swelling,
as a general rule, follows at the seat of such injection. If we analyse this symptom,
we find that on the day following the operation, a small raised somewhat
circular tumour appears, about one inch in diameter, while in some cases,
especially when the blood used was obtained some hours post mortem, the
measurements greatly exceed this; as in cases XXVII and XLI. On the
third day the swelling has increased in dimensions, and probably measures from
one and a half to two inches in diameter ; it now appears tense, and is tender
on manipulation. By the fourth day a still further augmentation in size, &c.,
has occurred, and from this date until the appearance of the hæmatozoon in the
blood of the general circulation, the swelling, tension, and tenderness of the
part may go on steadily increasing, or as sometimes happens, it remains station-
ary. At this time it will be found that if the tumour be firmly grasped by the