Chart I.
RAT SURRA
84
Date.
1892.
July 20 ...
„ 21
...
Day
of
Disease.
5
6
Temperature C°.
A.M.
37.4
38.0
1 P.M.
40.3
39.6
5 P.M.
40.3
40.0
Pulse.
A.M.
68
76
P.M.
80
88
Respira-
tion.
A.M.
24
20
P.M.
28
32
Hæmatozoa
in Blood.
Very nume-
rous.
Few
REMARKS.
20th.—The swelling and œdema of the
abdomen and extremities have increas-
ed. Urine red, Sp. Gr. 1,030, strongly
acid, no casts.
21st.—The animal is much weaker and
unable to stand. The pulse is frequent
and thready in character. The fæces
are coated with blood, and several clots
have been passed at intervals. Chloro¬
form was administered at 5 P.M. Death
at 5-5 P.M.
Autopsy, Immediately after death.
Body emaciated— considerable œdema of the abdomen and limbs.
Chest.—No fluid or adhesions in the pleural cavities.
Right Lung.—Superior surface is of a yellowish-pink colour, dotted over the surface with a number of black
patches irregular in outline, varying in diameter from 1/3rd to ¾th of an inch. There are also visible on the surface of
the lung small elevations, in size from a pea to a small marble ; these are covered by the lung-substance according to
the depth at which situated. On section, the black patches are found to consist of coagulated blood, which dips into
the lung-substance from 1/8th to ½ an inch. The elevations are found to contain calcareous masses in their centres,
surrounded by a zone of deep red-coloured thickened tissue. The right base presents a patch 6" × 8", over which the
pleura is thickened and infiltrated with yellow coloured jelly, which is raised ¼th inch above the general level of the
organ. This portion of lung is consolidated, and on section the tissue presents a red and yellow marbling, the indivi-
dual lobules being clearly defined and separated by a layer of this jelly, the whole appearance exactly resembling the
condition found in pleuro-pneumonia in the bovine species.
Left Lung.—The seat of hypostatic congestion. Well marked emphysema at the apex, and a peculiar marbling of
the superior border, presenting an appearance as if the superficial lymphatic vessels were visibly distended with a
yellowish green coloured fluid. On section, the appearance is found to be caused by the filling up of the septa
between the lobules with jelly. Similar calcareous nodules to those in the right lung are present in this organ, and the
base is affected as in the right lung for a distance of 8 or 9 inches.
The pericardium contains about two ounces of an orange-coloured fluid.
The Heart presents a dark red colour, with an orange-coloured exudation round the base; this material is dotted
over with petechiæ varying in size from mere spots to extensive patches grouped together. They are present in consi-
derable numbers, running down the sulcus with the anterior coronary vessels, and a few are visible accompanying the
posterior. Heart weighs 5 lbs. 1 oz. On section, the endocardial lining of the right auricle, right ventricle and left
auricle presents a yellowish tinge, but there are no petechiæ. The Left Ventricle.—The lining membrane and valves
have a slight yellow tinge, and there are several small sub-endocardial extravasations about ¼" in diameter.
Spleen.- Weighs 2 lbs. 6½ ozs. This organ presents a peculiar lumpy appearance on both surfaces. These eleva-
tions are well marked and stand 1/6th to ¼th of an inch above the general level of the rest of the organ. Some are
situated in close proximity with others, but do not coalesce. They are circular in form and firm to the touch, but on
section, nothing abnormal can be observed.
Kidneys. —Right weighs 1 lb. 5 ozs. Left 1 lb. 6 ozs. Capsules strip easily ; no petechiæ on the surface of the
organs. On section, they appear normal.
Liver.—Weighs 10 lbs. 6½ ozs. Old adhesions covering the convex surface of the organ ; Glisson's capsule being
somewhat opalescent. There are a few small calcareous nodules, dotted over the surface, and on section, these are
found to invade the tissues of the organ,
Stomach. —Normal in appearance.
Small Intestines.—For several feet from the pyloric end of the stomach, the intestinal tissues present an œdema-
tous condition. There are, however, no extravasations of blood, or parasites.
Cœcum.—Healthy.
Colon.—There are a few parasites adhering to the mucous membrane.
Observations.— In this case the animal was inoculated on the 14th of May with 2 c.c. of rat's blood containing very
numerous hæmatozoa. On the 15th there was slight swelling at the seat of inoculation, which continued until the 24th,
when it commenced to be absorbed and finally disappeared on the 31st. The animal continued in good health, the
only change noticed being slight swelling of the sheath and hind limbs, which disappeared on exercise. On the 16th
of July it was noticed that an urticarial eruption was present, and the symptoms of Surra were manifest. On exami-
nation of the blood, the hæmatozoon was found to be swarming, and the blood-stained mucus from the eyelids also
contained a few. On the 17th there was not much change in the animal's condition except that the temperature was
lower, and the frequency of the pulse and respirations less, and there were also fewer hæmatozoa in the blood. On the
18th the animal was worse, and the blood was again swarming with hæmatozoa. On the 19th and 20th the animal
became weaker, but continued to feed well, although the œdema of the extremities and under-surface of the abdomen
had increased. On the 21st the animal became too weak to stand, and chloroform was administered.
The points of interest in this case are—
(i) The extraordinary long period of 63 days intervening between the inoculation of the animal and the first
appearance of the hæmatozoon in the blood. This points to the absolute necessity of continuing the examination
of blood of animals inoculated, for a lengthened period, before giving an opinion as to the efficacy or otherwise of
the inoculation ; and also leads us to the conclusion that the hæmatozoon is capable of lying apparently dormant
in the body for a considerable, and, at present, undetermined, period of time, then suddenly springing into existence
in overwhelming numbers, and giving rise to most acute symptoms.
(ii) The acuteness of the attack, and the short period of only 6 days elapsing between the first appearance of
the hæmatozoon in the blood and the death of the animal.