80
TABLE XIV
Showing the number of days which elapsed in thirty-five cases of inoculated
Surra in horses, between the date of the first appearance of the hœmatozoon in the
blood, and death.
Bacteriological Laboratory
Percentage ...
1 to
5.
9
25.714
6 to
10.
2
5.714
11 to
15.
4
11.428
16 to
20.
6
14.285
21 to
26.
2
5.714
26 to
30.
6
14.285
31 to
35.
2
5.714
36 to
40.
2
5.714
41 to
45.
3
8.571
46 to
50.
...
61 to
65.
1
2.857
Total.
35
99.996
SECTION XII.
PATHOLOGICAL ANATOMY.
The most important element in Surra is the presence of actively moving
parasites in the blood. These were found by Evans in 1880, who thought at
first the organism was a form of spirillum, but quickly became convinced to the
contrary. Steele, in 1885, described and designated it the Spirochœte Evansi.
In 1886, Crookshank made a more detailed inquiry into its life-history, and
after recognizing that it was a flagellated Protozoon, called it Trichomonas
Evansi. At a later date, 1887, Osier referred it to the new genus Hœmatomonas,
described by Mitrapanow in 1883, to include the parasites of normal fish-blood,
as "Hœmatomonas Evansi." Balbiani, however, definitely considers it to be a
Trypanosoma, and that it ought to be called Trypanosoma Evansi, and in this he is
supported by Neumann. This flagellated infusorian is variously estimated as
measuring from 20 to 50 micro-millimetres in length, by about 1 to 1.5
in breadth at its widest part. It presents a body, with two extremities, one
being a short, sharp, somewhat rigid filament, the other long and slender, but
gradually tapering with a beautiful undulating and diaphenous membrane,
which extends from end to er:d, being best marked where the body is widest,
and gradually becoming narrower and less distinct, finally merging into the two
extremities.
A.—Generalities.
Emaciation,—The body is usually much emaciated, the word " Surra"
implying " rot" or " dry rot" ; and the disease is characterizedby a progressive
loss of flesh, or withering of the tissues. In some cases, however, when the
animal is carried off rapidly owing to the severity of the fever or from other
causes, it may be in fairly good condition.
B.—Infeguments, Muscles, and Bones,
1. Jelly-like exudation.—In the majority of cases there is found a varying
amount of a gelatinous, light yellow, or greenish-coloured material, lying in the
subcutaneous tissues ; this may occasionally be present in very large quantities,
especially in the neck, lying on either side of the trachea, in front of the sternum
and along the most dependent part of the abdomen, also involving the sheath
and the extremities. It is also frequently found between the muscles, and
running along the sheath of the nerves ; and in cases complicated with pneumonia,
the individual lobules of the lung are divided off, or iusulated by this jelly-like
material.
2. The Muscles.—The muscles of the back, especially in long continued
cases, are found to have undergone considerable atrophy. In the majority of
cases they are of a very dark red colour, as if the animal had succumbed to
asphyxia. When the case has been complicated by jaundice, all the tissues
present a more or less yellow tinge.
3. The Bones and the white tissues of the body generally are tinged
yellow in jaundiced cases.