69
of Horses Nos. 472 and 356, as examples of a point brought out by Steele, that
"the tracing from the number of pulse beats resembles that from thermometer
readings." In nearly every case of Surra, at one period or another, and usually
during one of fever, the pulse presents unmistakeable signs of irregularity
or intermission. I have noticed from one complete intermission in twelve
beats, down to as many as one in four, but in most instances a few hours later,
or on the following day, no trace of irregularity existed. During a period of
fever the pulse may vary considerably in frequency, according to the elevation
of the temperature, with or without intermissions ; the blood vessel during this
time feels round, and dilated with a moderate tension, the access of the pulsation
is sudden, and of short duration, and its subsidence abrupt, but is fairly easy of
compression between the beats, the walls of the vessel feeling smooth and elas-
tic. But a marked change appears during an apyrexial period, the frequency
is diminished or normal ; in many instances there is some irregularity, or the
pulse intermits, the beat is weak and thready, the access being gradual, its
duration long, and the subsidence slow, and the vessel feels flat, or at the most
only half distended with blood.
When the disease has been running on for a variable period, there comes a
time, only a few days before death, when continued fever usually accompanied
by daily remissions takes the place of the former type. During this period the
pulse is increased in frequency, 65 to 72 beats per minute, regular, but bounding,
forcible and large, reminding one of the force of the pulse of aortic regurgita-
tions, but in Surra the impulse is not visible in the carotids, or in the superficial
arteries. At the time of death the frequency of the pulse is greatly increased,
and may attain 120 or more beats per minute.
2. Action of the heart.—As a rule there is nothing noticeable with regard
to this organ, until the disease is fairly advanced ; when, after repeated attacks
of fever, with the accompanying organisms in the blood,' the animal becomes
more and more dull and dejected in appearance ; there is breathlessness on
exertion, very often sleeplessness and inability to lie down, together with an in-
capacity for a sustained exertion ; the heart's action then becomes exceedingly
irritable, and at a later date, when the bounding pulse appears as a result of the
condition of the organ, its action becomes violent and tumultuous, so that not
only is the animal swayed backwards and forwards by it, but by-standers are
able to hear the sounds at a distance of a few feet. At this time also jugular
regurgitation is observed, and distension of the superficial veins of the body,
particularly those of the head, and the large external or subcutaneous thoracic
vein, running from the flank towards the olecranon region.
c. —MORBID PHENOMENA PRESNTED BY THE ORGANS OF RESPIRATION.
1. The Respirating Movements are usually quickened from the first,
sometimes out of all proportion to the pulse, so that they amount to 60 or 65 in
the minute, quite independently of any pulmonary complication. The re-
spirations appear frequently to be entirely abdominal, and in these cases the
ribs are not seen to move at all. It has frequently been noted that animals
present a peculiar form of breathing, when otherwise they appear fairly well,
namely eight or nine shallow respirations are immediately followed by a deep
sonorous one, and this condition may last for several hours (Case LXXII).
Cheyne-Stokes respiration was noted in one animal, No. XXXVII, shortly
before death. In this case the animal had during the last few weeks of its life
suffered from severe kidney complication.
2. The Breath.--- During the greater part of the period the disease lasts
the breath is free from odour, but in the majority of cases, towards its last
phases, it becomes very foetid, and in cases complicated with ozœna, the mere
name is sufficient to describe the offensiveness of the discharge.
d.—MORBID PHENOMENA PRESENTED BY THE ORGANS OF DIGESTION.
(i). The tongue.—When the disease has fairly set in, the tongue and mem-
branes of the mouth become extremely pale, and at a later date assume a yellow
tinge. Some observers have noticed small symmetrically arranged ulcers, in
B 1086—18