64
tion. These conditions continue to increase, until by the fourth day, the
tumour may measure three or four inches in one direction, by two or three in the
other, and raised to the extent of an inch or inch and a half above the surround-
ing tissues, or in some cases present an almost circular form throughout, It
will be also found that if the tumour be firmly grasped, it is not fixed,
but can be lifted up from the subcutaneous tissue. According to the nature
and amount of the inoculated blood, so will these symptoms rapidly present
themselves, and either attain a maximum or be retarded, until, varying from
the fourth to the thirteenth day, the tumour at the seat of inoculation will be
found to have lost a certain amount of its tension and tenderness. From this
date the swelling and oedema will gradully begin to grow less, until finally after
a period of ten to fourteen days, the only sign left of the former swelling will be
a slight thickening of the skin over the point of injection. But at the moment
when the tension and tenderness of the parts at the seat of inoculation become
suddenly decreased, a symptom, of the utmost importance clinically, takes place,
viz., at that moment, the organism of Surra enters the blood of the general
circulation.
The temperature on the day of inoculation, and in fact for several days
afterwards, may remain normal in character, there being only a few points differ-
ence between the morning and evening observations. In other cases there may
be a slight rise from the first evening, and a gradual progressive rise until the
swelling at the seat of inoculation shows signs of reduction in size, when the
temperature generally takes a decided rise again, and may attain 40°C. or 41°C.
This elevation will last a varying period of from two to six days, and on the day
following its onset, the ordinary symptoms of fever will be noticed ; and in addi-
tion there will be petechiæ on the conjunctival membranes, lachrymation, a
slight mucous discharge from the nose, and in severe cases some oedema of the
lower portion of the extremities, and perhaps of the sheath in horses. At the
termination of the period of fever, the temperature will be found to have fallen
to normal, or nearly so ; the animal will present a brighter aspect, and there is
every appearance of its return to health ; but in a few days the animal again
appears dull and semi-somnolent; the temperature becomes elevated, and a
relapse takes place, and a repetition of all the symptoms in the primary paroxysm
including the re-appearance of the hæmatozoon, is observed.
C.—ANALYSIS OF PRINCIPAL SYMPTOMS.
a.—MORBID PHENOMENA REFERABLE TO THE SKIN.
(1). Eruption.—In the majority of cases, no eruption of any kind occurs dur-
ing the whole duration of the disease. Steele, however, noted in mules an erup-
tion of spots on the skin of the muzzle, resembling in its essential nature those he
had observed on the mouth and nostrils, In the course of this investigation, we
have observed a number of cases of urticaria, appearing somewhat suddenly, and
as a rule disappearing after a few hours, The eruption has been either general
or localized in character, and could be conveniently placed under several of the
different classifications :—viz., the affection which passes away in a few hours,
Urticaria ephemera, or within a few days (U. evanida), or the form which is
either preceded or accompanied by fever, (U.febrilis), and lastly the (U. nodosa
sue tuberosa) which is characterized by the appearance of nodosities of some size.
The following is a short account of the cases observed, twelve in number, placed
under the different groupings.
Naturally contracted.
Horse No. III.—The eruption appeared on the morning of the 18th day of
the disease, as far as could be ascertained, and invaded the skin of the head, neck,
and body. Temp. 37.9°C. a.m., rising to 40.4°C. in the evening. The hæma-
tozoon was absent from the blood daring the persistence, but on the morrow,
when the rash had entirely disappeared, it was present in small numbers.
Horse No. LXV.—An eruption broke out over the whole body, which passed
away in a few days, leaving fever, which continued until the 30th May, 1892.
This was the first symptom of Surra noted.