78
Autopsy at 11.30 A.M.
Body is fairly well nourished. There is œdema of all four limbs.
Pleural cavities.—Free from fluid ; no pleuritic adhesions.
Lungs.—Pale, present several small elevated extravasations of blood beneath the visceral pleuræ. There is a
localized emphysema at both apices, and at the free edge of the superior lobes.
Heart.—The pericardial sac contains a considerable amount of bright amber-coloured gelatinous material, between
the pericardium and the walls of the chest. The visceral pericardium presents numerous extravasations, especially
on the posterior aspect of the left ventricle. On section, the extravasation is found to occupy a position between the
visceral pericardium and the muscular structure of the organ, varying in thickness from 1/20th to ⅛th of an inch. There
is considerable hypertrophy of the heart as a whole. The right ventricle contains some small amount of dark-coloured
clot, but the greater portion is occupied by decolourised clots of ante mortem origin. The wall of the right ventricle
varies from ½ an inch to ⅛th of an inch in thickness. The internal surface of the ventricle after washing with water still
retains a red colour, which is due to post mortem staining. Scattered over the endocardial surface, especially over the
septum ventriculorum, there are several circumscribed patches deep red in colour which, on section, are found to be
caused by extravasated blood. These patches are raised above the general surface according to the amount of blood
effused. Valves—Healthy.
Left ventricle—The walls of this cavity are hypertrophied, considerably reducing its
capacity, measuring 2⅜ inches at its greatest thickness. Decolourized clots, as in the right ventricle, are found to
occupy the greater portion of its cavity, extending up the lumen of the great vessels. The walls are pale except at
the seat of the extravasations. The latter are far more marked than those in the right ventricle; they are extensive,
irregular in outline, and raised to a greater elevation than those previously noted ; the largest are observed to involve
the musculi papillares. Valves.— Healthy.
Liver.—Large.
There are signs of old perihepatitis on its convex surface. Glisson's capsule presents a considerable
number of round, circumscribed, opalescent patches, varying in size from 1/16th to ⅛ th of an inch in diameter. There
are also yellowish-coloured circular patches, very small in size, dotted sparsely over the whole surface of the organ.
On section, these appear to occupy a purely superficial position. One round calcareous concretion only is to be observed
on the under-surface of the left lobe.
Stomach.—Full of semi-digested food. No lesions.
Small and Large Intestines.—Healthy.
Spleen—Very much enlarged, soft, and presents numerous petechiæ on its surface. On section, the tissues are
soft and dark in colour.
Kidneys.—The capsules strip easily. The superficial surface of both organs presents very numerous round extra
vasations, 1/12 th inch in diameter, which, on section, are found to involve the cortical portion to the extent of from ⅛th to
¼th of an inch.
This horse being a " roarer, " the respiratory passages were carefully observed, and afterwards put by for future
examination. Superior opening of larynx, to all appearance normal. It is only on very careful inspection that it can
be observed that the arytœnoids cartilages vary in size at all ; the left presenting a slightly smaller contour than the
right. On looking at the true vocal cords, the right appeared slightly the larger, and the free edge more opalescent
than the left; the latter presented, at the junction of the posterior third with the anterior two-thirds, a somewhat
extensive extravasation under its superficial covering. This is irregular in outline, and its pointed extremity faced
the cricoid cartilage ; the large bellied cryco-arytœnoideus posticus and lateralis are also found to be well developed on
the right side ; while on the left, the same muscles were almost completely atrophied.
Remarks.—This was an Australian horse, aged, but in good condition and health. It was inoculated with blood
from the rat (mus decumanus) the blood of which contained very numerous hæmatozoa. Nothing of note occurred for
18 days, or until the 15th January, when hæmatozoa appeared in the blood, few in number. On the 17th, the
hæmatozoa were very numerous, and the temperature rose to 41.3°C. On the 18th, the hæmatozoa were absent and
the temperature fell to normal. On the 21st and 22nd the hæmatozoa were again numerous, and on the latter date
the temperature rose to 40.8°C. From the 23rd to the 29th hæmatozoa were absent. From this date the hæmatozoa
remained present, and were swarming two days before death. The temperature, however, did not, during this period,
exhibit any corresponding rise.
The points of interest in this case are :—
(i) Inoculation of the horse with the blood of the rat (mus decumanus) containing hæmatozoa produced
Surra.
(ii) The lengthened period, viz. 18 days, which elapsed between the inoculation of the animal and the first
appearance of the hæmatozoon in the blood.
(iii) The presence of a general urticarial eruption over the body two days after the appearance of the
hæmatozoon in the blood.
(iv) The comparatively short period which elapsed between the appearance of the hæmatozoon and death.
( v ) The extensive pathological lesions found post mortem in the heart, spleen and kidneys.