NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
TABLE I.— Showing alteration in weight of the viscera in acute and chronic cases.
N u m b e r
of
dog.
Weight
of dog in
grammes.
Weight
of
spleen in.
grammes.
Percent-
age of
body weight.
Weight
of liver in
grammes.
Percent-
age of
body
weight.
Weight
of both
kidneys in
grammes.
Percent-
age of
body
weight.
Date parasites first
appeared.
Date of death.
Duration
of disease
in
days.
REMARKS.
106
898
2.9 .323
38.6
4.4
12. ' 9
1.43
......
20th Nov. 1906
...
Normal dog.
118
658
1.3
.197
34
5.16
9.3
1. 41
......
21st
,,
, ,
. . .
Ditto.
107
981
6.1
.621
48
4.77
21.7
2.21
16th Nov. 1906 20th „
„
4
Acute. Hæmoglobinuria at death.
121
825
13.8
1.69
55
6.66
16
1.94
17th
,,
„
21st
„
„
4
Acute. Urine dark brown. Trace
of H.
122
807
10.3
1.26
65.6
8.12
I2.5
1.54
28th
„
„
1st Dec.
„
4
Acute. Paralysis of hind legs.
Hæmoglobinuria.
133
360
1.4
.39
13.5
3.75
4.8
1. 33 29th „ , ,
3rd ,,
,,
5
147
420
1.5
.357
14.9
3.55
4.7
1. 15
15th Dec.
„
18th „
„
3„
Dog killed. Probably would have,
died.
148
451
.9
.2
177
3.9
4.3
.947 15th
,,
,,
18th ,,
, ,
3
Ditto
ditto.
1 49
486
1.2
.247
21.4
4.40
5.40
1 . 1 9
1 5 th ,,
,,
18th
,, ,,
3
Ditto
ditto.
135
854
5.5
.644
55.7
6.52
13
1.52
18th
„
„
19th
„
„
1
Intense infection. About 300 para-
sites per field. Hæmoglobinuria.
136
985
9.5
.9
67
6.80
23
2.33
18th
,, ,,
23rd ,,
, ,
5
Urine pale.
139
1,900
28
1.5
125
6.58
21
1.10
18th
„
,,
29th ,, ,,
II
Dog killed. Probably would have
recovered.
146
757
19
2.51
52.8
6.97
16.3
2.17
1st Jan. 1907
4th Jan. 1907
3
Dog killed. Probably would have
died.
144
925
12.5
1.35
73
7.9
12.5
1.35
......
10th ,,
, ,
. . .
Urine deep yellow.
116
. . .
46.6
...
142
...
25.7
. . .
30th Oct. 1906 22nd Nov. 1906
23
Chronic disease.
117
1,459
467
3.2
115.7
7.93
18.8
1.28
30th „
„
23rd ,,
,,
24
Ditto.
131
2,210
27.7
I.25
211.7
9'57
20.6
.932
......
10th Jan. 1907
. . .
Ditto.
132
1,600
18.5
1.15
95.7
5.90
23.9
1.49
......
10th „
„
. . .
Ditto.
140
2,559
25
.977
210
8.20
24
9.37
......
. . . . . .
...
Ditto.
14
in a proportion of cases of Texas fever and malignant jaundice of the dog, but
is especially noted in infection with P. equi. Hæmorrhages are seen in Texas
fever and in biliary fever of the horse, as well as in East Coast fever, but they
are not common in malignant jaundice of the dog. Oedema under the jaw
occurs in East Coast fever ; and œdema of the subcutaneous tissues, especially
over the belly is described by Smith and Kilborne in Texas fever. In the dog
I have sometimes seen rather a characteristic œdema over the sacrum, and in
one or two acute cases this was associated with a gelatinous exudation about
the lower end of the spinal canal. The presence of abdominal and pericardial
fluid in canine piroplasmosis has been described by several authors, and the
former I have found especially common.
Enlargement of the spleen is a common result of piroplasmosis and is very
marked both in Texas fever and in biliary fever of the horse. In the dog en-
largement of the spleen to three or four times its normal size is described by
Nocard and Motas, who note that the gross changes in the organs are more
marked the longer the disease has lasted. Nuttall and Graham Smith state that
enlargement of the spleen and other gross lesions were not noticeable in their
cases, which were all of the acute type.
Even in very acute attacks I have generally observed some enlargement of
the spleen, which is more tumid than the normal organ, and is when first exposed
of a dark purple colour. In severe cases which have lasted some time, the en-
largement may be very considerable, as will be seen from the table giving the
weights of the organs in a number of cases. When greatly enlarged the organ
is firmer than normal and retains its shape when removed from the body. In
consistency it resembles the spleen of kala azar.
Changes in the liver are no less profound than those in the spleen. In
Texas fever Smith and Kilborne note enlargement, congestion, bile injection,
and fatty degeneration. Congestion and dilatation of the bile capillaries are
noted by Bowhill in horses, and by Dale in donkeys, which have succumbed to
piroplasmosis. In East Coast fever infarcts occur in the liver and other organs.
In the dog Nocard and Motas describe engorgement and an appearance
resembling the liver of cardiac disease. In my own cases the liver has always
been pale in colour and in long standing cases shows mottling, probably due in
part to fatty changes. In all chronic cases there is an increase in weight as
shown in the table.
The condition of the kidneys in my cases has varied. In many acute cases
they have been normal in appearance, but in others, especially when hæmoglo-
binuria was present, they have been enlarged and congested. In chronic cases
they are often enlarged and pale in colour, their consistence being very firm.
In other cases, except for pallor, they are not abnormal.
15
The other organs show appearances attributable to intense anæmia, rarely
any other change. But the red marrow is increased in amount and in chronic
cases has a fætal character.
MORPHOLOGY OF THE PARASITE.
With the exception of the minute parasites of East Coast fever all the
known piroplasmata are somewhat similar in appearance and approximately pear-
shaped forms occur. Nocard and Motas state that Piroplasma canis is
morphologically indistinguishable from Piroplasma bigeminum, but Robertson
describes Piroplasma canis as more oat-shaped, an opinion in which Nuttall sup-
ports him. In the Madras parasites the difference is quite distinct, Piroplasma
bigeminum being much more strictly pear-shaped than Piroplasma canis, whilst
it is at the same time smaller. Measurements of the same species of piroplasma
by different observers often vary considerably, a result one might expect, since
both apparent and real variation in size occur under different conditions of pre-
paration and of infection. For Piroplasma canis Piana and Galli Valerio give
2.5—3.5 µ Marchoux 2—4 µ , Nocard and Motas note large forms occupying
half the red cell, Nuttall and Graham Smith give the measurement of the
African parasite as from .7 to 1.2 µ though they note that larger types reach
3.6 µ and occasionally even 4.5 to 5 µ.
In the case of Piroplasma bigeminum
Smith and Kilborne in America give .5 µ, Laveran and Nicolle in Constantinople
1—3.5 µ, and Ziemann in Venezuela .75 to 3 µ so that smaller forms of this para-
site appear to be more frequent. For P. ovis Bonome gives 1—3 µ and Laveran
and Nicolle 1—2 µ. P. equi is considerably smaller, the usual size being given
by Laveran as from 1—1½ µ the largest forms not exceeding 2½ µ.
In all species multiple infection of the red cell is seen, the characteristic twin
parasites being characteristic of all except P. parvum. In P. equi forms arranged
in the manner of a cross are stated to be characteristic but similar forms occur in
P. canis and are especially noticeable in blood taken post-mortem from the heart.
P. equi is figured by Laveran (169) as small round forms, but in the figures given
by Bowhill (163 a and b ) this parasite does not differ very greatly in general
appearance from Piroplasma canis.
In Piroplasma canis all observers have noted the infrequency with which
corpuscles contain an odd number of parasites. Graham Smith, dealing with large
numbers, has demonstrated this clearly and gives instructive figures regard-
ing the number of parasites in red cells. These will be referred to again in
another connection. According to this author single forms predominate, forming
from 50 per cent. to 76 per cent. of the total forms in the peripheral blood and
from 29 per cent. to 50 per cent. of those in the organs. Next in frequency come
the double forms which as a rule form only from 20—30 per cent. of the whole,
16
though even in the peripheral blood they are noted as rising to 43 per cent.
In the organs they averaged about 40 per cent. and reached in the case
of the marrow 52 per cent. of total forms. In striking contrast to these figures
are those showing the percentage of infected cells containing more than two
forms. In the peripheral circulation cells infected with four parasites number
only from 2—5 per cent., those with eight forms less than .05, and those with 16
forms from .004 to .01 of the whole. The figures for cells in the viscera con-
taining more than two parasites are higher but the numbers are still far below
those of the single and double forms, the highest percentage given for cells
infected with four parasites being 12.39 and for those containing 16 forms .01.
Corpuscles containing an odd number of forms are comparatively very few,
corpuscles in which there are three parasites numbering only .7 of the whole,
whilst those containing higher odd numbers are still rarer.
My own counts, though they have not been based on such large numbers,
correspond in the main with those given by Graham Smith, and they also show
that, no matter at what stage of infection the blood be taken, the forms maintain
an approximately similar relationship to one another.
Thus corpuscles containing single forms have varied from 22 per cent. to
81 per cent., but are usually 50—60 per cent.; those with double forms from 18
per cent. to 50 per cent. but are usually 30—40 per cent. ; and those with
over four forms rarely exceed 20 per cent. and are usually from 5 to 10 per cent.
As will be seen later this general order of frequency, although it is never
completely upset, is subject to certain definite and important variations which
have a cyclical significance.
The piroplasmata are described by the earlier observers as parasites of
simple form possessing a single nuclear mass of chromatin ; and except in Piro-
plasma canis little further structure has yet been demonstrated. Koch, however,
mentions in Piroplasma bigeminum a large and a small mass, the latter of which
is situated towards the thin end of the parasite ; and Fantham notes in P. muris,
nuclear characters of some complexity.
Piroplasma canish a s b e e n t h e s u b j e c t o f m o r e d e t a i l e d s t u d y a n d a l a r g e
and somewhat perplexing number of forms have been described. A very
complete study of the parasite in the living state has also been made by Nuttall
and Graham Smith (160). To facilitate description it will be advisable to men-
tion the various forms noted by different observers, although most, if not all, are
but stages in growth and fission.
Amœboid forms.—All observers who have studied the living blood note the
protrusion of pseudopodia and movements so active as sometimes to move the
corpuscle in which the parasite is situated. Nocard and Motas state that para-
sites exhibiting amœboid movement are best seen during the febrile state, and that
17
after this they lose their amœboid properties and remain immobile in the centre
of the cell.
Nuttall and Graham Smith distinguish between two forms of amœboid para-
site, those which show only slight amœboid movement and those with well
marked pseudopodia.
Both forms can be correlated with forms seen in stained preparations. The
actively amœboid forms appear in stained films as triangular, elongate or irregular
forms, and when parasites of this type are watched in the living state they will
be seen constantly to assume a shape more or less triangular as shown in Pl. 1,
fig. 12. Another very common appearance is that of a long almost vermicular
form stretched across the corpuscle (Pl. 1, figs. 13 and 16). Ordinary amœboid
shapes are also seen in stained films and usually represent parasites in process of
changing from one of the above-mentioned shapes. At certain times, notably
when parasites are extremely abundant, appearances which suggest extraordinarily
active amœboid movements are seen, and parasites exhibiting these movements
may show in addition to pseudopodia the long flagella-like processes described
by several observers.
The triangular, elongate, and irregular forms represent undoubtedly the
actively growing parasite which in the living state is in active amœboid movement.
Pear-shaped forms. —These are so characteristic and well known that a
description is scarcely necessary. The majority of the parasites come under
this heading, and as a rule when more than a single parasite is present in a cell
each is more or less pear-shaped. When four, eight or more parasites are included
in a single cell they are nearly always more or less pear-shaped, but with a tendency
to become somewhat polygonal. Of pear-shaped parasites several distinct
varieties are seen. The most typical are those resulting from fission, but a pear-
shaped form may be assumed at the end of the period of growth and prior to
division. These are large parasites readily distinguishable from the smaller and
more strictly pear-shaped forms which are seen as a rule most typically in cells
containing four or eight parasites. Pear-shaped forms also vary much in size and
in the reaction of the protoplasm to stains. Those staining a more or less uni-
form and comparatively dark blue colour are the most common. In thin portions
of films these are less pear-shaped than in the thicker portions where the para-
sites are contracted laterally.
The pear-shaped forms resulting from the fission of a single large form are
very often rather globular bodies and most frequently stain more lightly than the
forms just mentioned ; the chromatin also is usually situated more peripherally than
it is in the multiple forms where the chromatin is usually nearly central in position.
The formation of the pear-shaped forms by fission occurs in two or even
three distinct ways.
D
1. In the case of certain large parasites, characteristic of early invasion and
of infection in young dogs, the division takes place in a manner described by
Nocard and Motas. After the chromatin has divided a dark line forms across
the parasite in the centre of which a cleft is later seen. This gives rise to two
closely approximated bodies. (Pl. 1, figs. 4—7.)
2. In parasites which immediately before division are round or oval in shape,
division takes place so as to give rise to the appearances first described by
Nuttall and Graham Smith who believe this to be the usual method. Signs of
division are first evidenced by the two masses of chromatin surrounded by more
or less protoplasm passing outwards from the parasite. In some cases the
chromatin bodies have so little protoplasm that they appear to be extruded. In
others about a third of the protoplasm surrounds each mass giving rise to the
trefoil appearance noted by Nuttall and Graham Smith. Eventually in all cases
the whole of the protoplasm is drawn away from the original body of the parasite
to one or other of the chromatin masses, which become the nuclei of two new
parasites joined at first by their apices, but afterwards free. (Pl. 1 , figs. 21—23
and figs. 1, 1—6, page 21.)
The various stages and varieties of this process are responsible for many of
the appearances seen in stained films.
3. A method of division, almost if not quite as common, takes place when
the parasite is stretched across the cell. The long oval becomes constricted in
the centre and the two ends passing away from one another become two pear-
shaped bodies: (Pl. 1, figs. 9—14 and figs. 1, 1—6, page 21.)
4. It happens not infrequently that a second fission is in progress even
before the first is completed so that four forms are produced almost simultane-
ously.*
Early infection forms. —Nocard and Motas describe at the commencement
of infection large forms nearly filling the corpuscle. They note that these are
specially large in young dogs. In my cases the first parasites seen have
generally been of this character and they must be looked upon as a distinct type,
though the transition of these forms into the pear-shaped forms is easy to follow.
A few parasites of this type are generally seen at the commencement of infec-
tion and within a very short time they become comparatively abundant in the
blood. In young dogs, as noted by Nocard and Motas, the single forms are
especially large and may reach 4 µ in diameter occupying nearly all the cor-
puscle.
The chromatin mass is usually peripherally situated. The protoplasm is
reticular and slightly refractile. In the early stages ring forms somewhat
* This gives rise to t he appearance of budding described by Kinoshito but it is very doubtful whether a
permanent "reliquat " is left.
19
r resembling those of the malarial parasites are common. These have to be
distinguished from the apparent ring forms with refractile centre described later.
As the parasite grows the ring tends to disappear and changes of an amœboid
nature take place, the parasite becoming racket-shaped, triangular, oval, or
elongate. Eventually a large slightly oval body is formed in which the chromatin
has become separated into two. Fission of these forms usually takes place in
the manner described by Nocard and Motas rather than in that described by
Nuttall and Graham Smith. By development into four forms the parasites
approximate either to the ordinary pear forms, by the chromatin becoming more
central and the protoplasm bluer, or into the round refractile type, the chromatin
in this case being pushed still more to the periphery.
Round refractile type.—Nocard and Motas make special mention of these
forms which are referred to only incidentally if at all by other observers. At
times almost all the parasites are of this type ; at others they are found lying
side by side with ordinary pear-shaped forms so that the appearance is not one
due merely to fixation or staining. These parasites are often round, but where
they form members of a group they are usually slightly pear-shaped. They
have a narrow darkly staining portion and a brightly refractile centre. The
chromatin is not only peripherally situated but is flattened. Nocard and Motas
describe it as sometimes occupying nearly two-fifths of the periphery, and such
an extended area is quite common. Between these and the large early infection
type there are transitional forms which as they divide to form groups of two and
four may take on the characters noted. Groups of four are the commonest and
these show the characters very markedly, but groups of eight may occur.
In the fresh condition these forms are quite motionless, but in stained speci-
mens amœboid processes of the kind shown in Pl. I fig. 27 are occasionally
seen.
Similar forms are seen in the large bovine piroplasma of calves of Madras
and are also figured by Myajima and Shibayama (102) in the piroplasma of cattle
in Japan.
The significance of the forms is not clear.* Nocard and Motas consider
them a resting stage and they note their presence after the febrile period, an
observation which I can confirm. They can scarcely, however, be due merely
to immunity following an attack, for they may occur along with the ordinary type
of parasite.
Ring forms.—These have been especially noted by Luhe. True ring
forms occur, especially in the early invasion forms, but also in the case of other
single parasites. In some cases one or more true vacuoles are also present.
•
* Kinoshito describes certain forms as gametes, but the evidence given in favour of this view is not very
convincing.
D 2
20
Vacuolated forms. —Large oval or irregular bodies shewing vacuoles are not
uncommon at the stage of active growth.
Flagella-like processes. —These have been described by Pound, Bowhill,
and Le Doux in Piroplasma canis and by Lignières and Bowhill in the large
piroplasmata of cattle. They have been described by Nuttall and Graham Smith
both in free parasites and in intracorpuscular forms. In the former case a flagel-
lum-like process often projects from the thin end of the parasite. In stained
films this is only occasionally seen, but in parasites examined in the fresh state it
is not only very frequent, but is seen to exhibit active movements.
These authors describe in intracorpuscular parasites the occurrence of one
or more very long and thin wavy flagella ending in a minute knob or more rarely
in a fine point.
These fine pseudopodia are frequently seen in the actively growing forms at
the height of invasion and, as noted by Nuttall and Graham Smith, they are a
feature of cultures. That they have any sexual function as supposed by Doflein
is improbable and they appear to represent merely an exaggeration of amœboid
movement associated with specially active absorption of material by the parasite.
Post-mortem forms. —Forms seen in the blood taken from the heart a short
time after death are as a rule reduced in size and globular. They also stain
intensely, having an appearance quite different from that of parasites prepared
in the ordinary way from living peripheral blood. Not infrequently tags of
protoplasm are present and sometimes these may be quite detached from the
parasite. The chromatin, though obscured by the dark staining protoplasm, still
stains and is central in position. Unchanged forms may also be present. (Pl. 1,
figs. 41 and 48.)
Free forms. —Free forms are described by nearly all observers, and they
are a conspicuous feature of films taken at certain times. They may be
single, but are more frequently seen in groups of two, four, eight, or sixteen
and have evidently arisen by rupture of a cell a short time before. In many
cases the outline of an enlarged and colourless corpuscle is visible. Free forms
differ from the included ones in that they stain a much deeper blue and are
almost invariably pear-shaped or show an approximation to this shape, though a
somewhat angular outline is characteristic. The size of free bodies varies consi-
derably, and very large forms are often seen as the result of rupture of a cell
containing two parasites only. When one of a group of sixteen they are usually
much smaller.
The chromatin of the free forms is nearly always more or less centrally
situated.
Nuttall and Graham Smith consider that in normal development included
forms, after division into two, are liberated and again penetrate cells, but it is
21
evident that many parasites go on to the formation of four, eight, or more forms
before they are liberated by rupture of the cell, a condition which, as we shall see
later, probably represents the commonest cycle of development. The matter has
some importance since it is quite possible that not all parasites on being liberated
by rupture of the cell are in a fit condition to penetrate fresh cells. Thus we may
distinguish, for example, between forms liberated immediately prior to division,
those liberated after a single process of fission, and those resulting from fission
repeated many times. Further observations on these points are required.
FIG. I.—Showing movements of Chromatin in the process of binary , fission.
Fig. 1—Parasite showing early signs of fission. Appearance of blepharoplast.
Fig. 2.—Passage of chromatin to neighbourhood of blepharoplast
.
Fig. 3.— Division of new chromatin mass into two.
Fig. 4.—Protrusion of the two new masses and passing over of remainder of the original mass.
Fig. 5.—Protoplasm flowing past the two new chromatin masses.
Fig. 6.—Showing apical position of the chromatin masses due to protoplasm flowing past them.
Fig. 1.—Parasite prior to changes leading to fission.
Fig. 2'.—Similar stage to 1, but parasite elongated.
Fig. 3'.— Similar stage to 5. Parasite stretched across corpuscle.
Figs. 4', 5', 6'.—Final stages in second type of division.
The chromatin .—A large compact mass of nuclear nature has been de-
scribed by all observers. Later Schaudinn (10) and Luhe(7)have drawn attention to
the presence of a minute punctiform mass, which they consider to be of the
nature of a blepharoplast. Nuttall and Graham Smith note that in many of the
parasites three distinct masses of chromatin are found, a large and compact mass,
the nucleus, a minute dense punctiform mass usually lying in the immediate
neighbourhood of the nucleus, the blepharoplast of Schaudinn and Luhe, and a
third lightly staining irregular loosely packed or reticulated mass hitherto un-
described. These authors further describe and figure a great many variations in the