80
RAT
SURRA
Thorax.—There are no adhesions or fluid in the pleural cavities.
Lungs, Large.—There is localized emphysema at the apices and along the free edges of both organs ; dotted about
are large numbers of small ecchymoses, which are found to lie under the visceral pleuræ. On passing the hand over
the surface of the organs, rounded eminences are felt from half an inch to one inch in diameter, somewhat hard to the
touch. On section of the organ at a depth of half an inch from the surface, irregular-shaped, yellow-coloured calcareous
masses are found, which are for the most part situated in the middle-third of the anterior lobes ; but a few are scattered
over the posterior lobes.
There is no fluid in the pericardial cavity.
Heart.—Weight 5 lbs. 13 ozs. The external surface of the heart is the seat of a considerable deposit of exudation
light-yellow in colour, principally at and around the base, and running down the course of the coronary vessels. The
muscular structure is dark in colour over a considerable portion of the organ, due to the numerous small extravasations
of blood, which have become confluent. The right auricle and ventricle contain considerable masses of bright orange
clots which are continuous with those in the large vessels ; whilst externally the clots are bathed in dark coloured semi-
fluid blood. Lying under the endocardium are large masses, dark in colour, almost black, which are due to sub-endo-
cardial extravasations, and which on section do not appear to involve the tissues of the organ. The valves are healthy.
The cavities on the left side of the heart present similar appearances to those described on the right, with this difference,
that they are not quite so extensive in character ; but the auriculo-ventricular valves present petechiæ of some size on
their internal surfaces.
Spleen.—Weighs 5 lbs. 10 ozs., is large and the tissues soft, the vessels on the surface of the capsule are injected
There are some small extravasations upon the capsule.
Liver.—Weighs 10 lbs. 5 ozs.; is firm and of a healthy appearance, presenting several small calcareous nodules on
the surface ; but on section, none are seen invading the tissues.
Stomach.—On section, contains some semi-digested food. The cuticular portion is quite white and healthy ; the
villous portion presents a dirty-grey colour, and there are patches of a purplish hue lying midway between the pyloric
extremity and the boundary-line. One patch has lost the superficial mucous membrane, and, whilst pale in the centre,
is congested round the edge of the erosion.
Kidneys.—The Right weighs 1 lb. 8 ozs., and the Left 1 lb. 4 ozs. The capsules strip easily, and each organ
presents numerous circular patches, greenish in colour, dotted over the external cortical surface. These circular
patches vary in size from that of a two-anna piece to half the size. On section.—The tissues appear pale, and the
circular bodies are found to be crystals, which contain a small quantity of a semi-gelatinous material. These dip into
the cortical portion forming small cavities.
Small Intestines.—The mucous membrane is dotted over the surface at considerable distances apart with aggre-
gated patches of small round petechiæ, dark-red in colour.
Large Intestines.—Present a healthy appearance.
Nasal fossœ.—The Schneiderian membrane covering the turbinated bones is considerably thickened, and is dark-
purple in colour, but there is no ulceration.
Brain.—The membranes are pale; but the superficial veins are deeply congested and the convolutions flattened,
The lateral ventricles are distended with a clear fluid, which on microscopical examination is found to contain a few
hæmatozoa.
The points of interest in this case are :—
(i) The blood of Rats (Mus decumanus), containing hæmatozoa, transmitted Surra to the horse, when it was
inoculated subcutaneously.
(ii) A period of 29 days from the time of the inoculation elapsed before the hæmatozoon was found in the
general circulation of the animal.
(iii) The period elapsing between the first appearance of the organism in the blood and death was only two
days.
(iv) The extensive lesions found at the Autopsy.
(v) The presence of the hæmatozoon in the cerebrc-spinal fluid.
HORSE No. XLII.
Subcutaneous inoculation with soiled rat's blood : Local symptoms at seat of inoculation ; Appearance of hæmatozoon
after latent period of 13 days ; Death on the 2nd day of the disease ; Marked pathological lesions present post
mortem.
Chestnut, country-bred horse, aged, healthy, and in good condition.
Date.
1891.
Septem. 1 ...
„
15...
„ 16 ...
„
17...
„
18...
„ 19...
„ 20 ...
„
21...
Day of
Disease.
...
...
...
..
...
...
...
Temperature °C.
A.M.
38.2
35.3
35.6
36.5
36.5
36.4
36.3
... |36.4
1 P.M.
38.2
36.2
37.0
36.6
37.0
37.7
36.4
37.2
5 P.M.
38.2
36.7
37.2
37.0
37.5
36.7
36.5
37.6
Pulse.
A.M.
36
36
36
44
36
40
32
44
P.M.
36
40
40
36
36
36
32
36
Respiration,
A.M.
18
20
20
20
28
16
14
16
P.M.
13
16
12
16
16
16
16
14
Hæmatozoa
in Blood.
Healthy.
„
„
„
„
„
„
„
URINE.
Colour.
...
...
...
...
...
...
Turbid.
„
Sp. Gr.
...
...
..
...
...
...
1,023
1,017
Re-action.
...
...
...
...
...
...
Strongly
Alkaline.
„
Albn.
...
...
...
...
...
...
Nil
„
Hippuric
Acid.
Nil.
4 P.M. The animal was inoculated subcutaneously with 2.0 c.c. of blood containig numerous hæma¬
tozoa taken from the rat (Mus decumanus) immediately after death, 1 c.c. of blood was
injected over the right scapular region, and the other at the root of the neck on same side.