Symptoms. Definition: protozoan, tick-borne, febrile, affection, of
wild damp lands, and warm seasons, with enlarged spleen and liver and
hæmolysis. Historic Notes; Old World; Australia; tropical and
subtropical America. Causes: contact of cattle from salubrious
districts with the insalubrious or with cattle from such; Piroplasma
bigeminum; a bovine parasite, reducing red globules by ¾ths.;
successive forms of piroplasma; the cattle tick, boöphilus bovis,
bearer of piroplasma; demonstration of the tick agency; toxic saliva
of tick; toxic property in blood; question of identity of
infection-bearing ticks. Lesions: putrefaction rapid, icterus, ticks,
blood oozing in skin, hydræmia, hæmoglobinæmia, few red globules,
small petechiæ, slight serous exudates and effusions: congestion,
petechiation, sloughing, perforation of gastric mucosa, congestion of
intestinal mucosa, in rectum like port wine; liver enlarged,
congested, biliary radicles in acini gorged with bile; spleen
enlarged, engorged; kidneys œdematous, blood-stained; bladder
petechiated; urine opaque or red, in convalescence watery; womb;
fœtus. Incubation three to ten days; delays due to hatching of ticks.
Symptoms: Acute case: anamnesis; hot season; hyperthermia 104° to 109°
F.; hurried breathing and pulse; anorexia; dulness; costiveness;
icterus; prostration; weakness; delirium; urine turbid, red; blood
hydræmic; diarrhœa; emaciation. Duration one to seven days. Fatal
(90%) to exotic cattle; mild in indigenous, or cool season. Mild case;
temperature 103°, anorexia, dulness, costiveness, enuresis,
albuminuria, pallid mucosæ, emaciation, round protozoön in globules,
ticks, oligocythemia. Differential diagnosis, from anthrax. Treatment:
laxative; antiseptic; mucilaginous food; picking off ticks;
anti-ixodic lotion; tick-free pasture or place. Prevention:
destruction of ticks; picking; dipping or smearing with tick killing
preparation, paraffin or extradynamo oil and sulphur, danger with
shipping; dressing of all cattle at intervals during warm season;
cultivation of tick-infected land; exclusion of cattle for one summer
and two winters; soil cattle for three weeks in each of two tick free
pens, to let ticks drop; danger of nonimmunized cattle in infested
area; suggestions for extinction by States. Immunization: Infection of
sucking calf; infecting by a few ticks: by graduated injections of
piroplasma blood; technique; injection of blood from body of tick.
Limited value of artificial tolerance. Marketing of the beef. Federal
restrictions.
_Synonyms._ Splenic fever; Spanish fever; Mexican fever; Southern cattle
fever; Australian tick fever; Tristeza; Red water; Black water; Bovine
periodic fever; Bovine yellow fever; Maladie du bois; Holzkrankheit;
Moor evil; Wood-ill; Ixodic Anæmia; Roumanian hæmoglobinuria.
_Definition._ A specific fever of cattle, enzoötic during the warm
seasons in the low, malarious grounds and wooded or uncultivated
districts of different countries, caused by a protozoön in the blood and
red globules, which is conveyed from animal to animal by ticks, and
leading to engorgement of the spleen and liver, destruction of the red
globules, hæmoglobinuria, and oligocythemia.
_Historic Notes._ This malady has doubtless existed from time immemorial
in different malarial districts of the Old World, where the wood and
moor ill is now coming to be recognized as a protozoan tick-borne
disease. The malady exists in Roumania (Starcovici, Babes, Gavrilescu),
Turkey (Nicolle, Adil-Bey), Sardinia (San Felici, Loi), Southern France
(Lignieres), Italy (Celli, Santori), Algiers, Tunis (Lignieres), Finland
(Krogins, Von Hollens), West Indies, Mexico, Nicaragua, United States of
Columbia, South America as far south as the Argentine Republic, German
East Africa (Koch), Transvaal (Theiler), S. Australia (Pound). In
Australia imported European cattle found the infection waiting for them
in the uncultivated bottoms. In America it doubtless prevailed on the
seaboard and islands of the Gulf of Mexico from the time of the
importation of Spanish cattle, but for the first definite account of it
we are indebted to Dr. James Pease, who records the widespread
destruction of the native herds in Lancaster, Co., Penn., in connection
with the introduction of cattle from the south. None of the southern
cattle died, but wherever they traveled, the native stock perished all
but universally. Other droves from South Carolina were equally
destructive to all cattle along their track. The recorded symptoms of
anorexia, great weakness, often inability to stand, trembling, groaning,
bloody urine, bleeding from the nose, costiveness, congested kidneys,
and decomposed, incoagulable blood serve to identify the disease.
Later, whenever southern cattle were moved north, the disease followed
their trail. Florida cattle left infection along their route until they
reached the border of Virginia, where it usually ceased. When taken from
the Georgia mountains to the lowlands, they died without infecting the
native stock, and, when such native stock of the lowlands were moved to
the hills or the north, they conveyed the fever to the stock among which
they came, though themselves well and improving all the time
(Wilkinson). Similar experiences were had in all the middle states up to
the war of 1861, but, in too many cases, the real source of infection
was overlooked. It was observed that the disease was confined to the
vicinity of the main highways and drove roads running north, and spared
the lands lying somewhat back of these routes. Attention was drawn to
the Texas cattle in 1853 when a herd of 450 which had wintered in Jasper
Co., Mo. moved north passing through Vernon Co. in June, and causing
losses of 50 to 90 per cent. of the native cattle along their course,
and only along that line. Such invasions occurred yearly, and in 1858
$200,000 worth of native cattle perished from this cause in Vernon Co.
alone (A. Badger). During the war (1861–64) the cattle, in Texas
especially, encreased without meeting with an adequate market, and, on
the opening of the trade once more, they were sent north in large
numbers carrying infection with them. When Forts Smith and Gibson had
been occupied by the Union soldiers, the southern cattle poured in along
the military road and the Kansas farmers along this route suffered
severe losses, as well as those to whom the southern cattle were finally
distributed (Bray).
_Causes._ Up to 1889 the true cause of Texas fever was unknown. It was
well established that cattle brought from the lowlands of the southern
states, during the warm season, though themselves in apparently the best
of health, proved deadly to northern cattle with which they came in
contact, to those that followed them in the same pasture during the same
warm season, and even in many cases to the mountain cattle of the south.
In the same way northern cattle, removed to the infected regions in the
south, contracted the fever and almost all perished. This was equally
true of cattle taken from the northern states to Jamaica or other
islands in the Gulf. In the winter season, after the first severe frosts
of autumn and before the last keen frosts of spring, the southern cattle
could be safely introduced into the northern states and on this a modus
vivendi, for a trade in southern cattle in the winter only, was based.
_Microbiology._ _Piroplasma bigeminum_: _Apiosoma bigeminum_. (Apios
pear, geminus twin). In 1888 Starcovici discovered pyriform organisms
(_Babesia bigeminum_) in the red blood globules of Roumanian cattle
suffering from hæmoglobinuria, and Babes, after a study of the
organisms, named them _Hœmatococcus_. The following year Theobald Smith
found them in the Texas fever blood, and recognized them as protozoa
(_Pirosoma bigeminum_). Wadoleck proposed _Apiosoma_, Bonome
_Amœbosporidia_, and Patton, _Piroplasma_. The latter pointed out that
_Pirosoma_ was already in use for another organism. Th. Smith’s
discovery identified Texas fever with the Roumanian hæmoglobinuria, and
stimulated the Bureau of Animal Industry to an extended research which,
in the main, elucidated the true nature of the disease. In a long series
of experiments the observers produced the disease in healthy susceptible
cattle, by injecting them, in the warm season with the blood of sick
animals, and as constantly failed in the experimental inoculation of
similar blood on non-bovine animals such as sheep, rabbits, Guinea pigs
and pigeons. In Australia, Pound had violent fever in two injected sheep
but no pyroplasma, and their blood injected on the ox, had no effect. In
none of these latter were the blood globules invaded by the parasite,
nor were the corpuscles lessened in number. In the affected cattle, the
red cells were reduced from the normal 7,000,000 per cubic mm. to
1,800,000 and even lower in some cases.
The _Piroplasma Bigeminum_ passes through a series of forms in the
blood. Theobald Smith found in the red globule and attached to its
margin a _pale round body_ 0.5μ in diameter, and staining freely in
_alkaline methylene blue_ and other basic anilin dyes and in
_hæmatoxylin_, but not in acid coloring fluids. These he found in the
red globules in acute cases, often in company with the pear-shaped
bodies, and usually in the absence of the piriform bodies in chronic
cases, in non-fatal relapses, in cases occurring in cooler weather,
(late autumn or early winter) and in immune southern cattle. The red
cells containing these rounded organisms were not crenated nor
distorted, though 50 per cent. of them might contain the parasite. He
looked on these as the earlier stage of the organism which later
developed into the _piriform body_, by segmentation of its substance.
The _piriform_ or _spindle-shaped bodies_ were usually found in pairs
connected at their pointed ends by a filament and extending across
nearly the whole breadth of the red globule. _Free microörganisms_,
pear-shaped or round, he failed to find in the blood of the large
vessels, but saw them only in the cardiac capillaries and especially in
the kidneys. In some cases the dim remnant of the disintegrated blood
globule could still be detected around the parasite.
Laveran and Nicolle, examining the blood of Italian cases by fixing and
staining, found the two forms, round or oval, and piriform, and claimed
that the first passed into the second by segmentation.
Lignieres working in Buenos Ayres with the most ample opportunity as
regards fresh material and authority to use it, watched the successive
changes in the living organisms, and reached further conclusions. He
diluted the blood with a 7 per cent. salt solution, or with ox serum or
both, until the globules stood apart in the field. The blood can be kept
under observation for days under a cover glass luted with sterile
paraffin, and the changes clearly traced. Securing the blood from a
subject having a great abundance of infected globules (usually at the
height of the hæmoglobinuria) he found mainly the _piriform parasite_
intraglobular and free, and in the latter an active whirling motion was
kept up by means of the flagellum at its pointed end. As usually
arranged in pairs (gemina), whether inside or outside the globule, they
are connected by the flagellum attached to their pointed ends. Careful
observation enables one to detect in the pyriform mass a small brightly
refrangent point like a nucleus. In this form the piroplasma is 3 to 4μ
in length.
After 4 or 5 hours, and on toward the 8th, the piroplasma has assumed
the _round_ or _oval form_ with a small linear prolongation (flagellum)
and shrunken to 1 to 1½μ in diameter. All the piriform bodies pass into
the rounded so that this last is the second stage of their development
and not the first as was formerly supposed. The round forms are always
present in great numbers in the cortex of the kidney in the second stage
of the disease (toward the subsidence of the hæmoglobinuria). The
refrangent nucleus is no longer to be seen.
After, one, two or more days there appears in the round parasite a
_chromatine mass_, which breaks up into 2, 3, 4 or 5 smaller _chromatic
bodies_, which Lignieres considers as germs. He has seen no division of
the protoplasm, but on the contrary the germs escape, yet remain for a
time attached to the outer surface of the parent organism. They show
rapid jerking movements.
Lignieres claims to have followed all these changes in the blood kept in
a sterilized glass cup at room temperature or in the thermostat, and in
the stomach of the tick, as well as on the warm stage of the microscope.
He claims to have made a further success in cultivating the parasite in
ox-blood serum highly charged with hæmoglobin. It was only occasionally,
and by the use of blood extraordinarily rich in the parasites, that
success was obtained. In one such case he produced five successive
cultures, the product being the rounded forms only and within these the
germs. There were no piriform bodies. These are not formed outside of
the red globules. The third successive culture in this medium grew with
great readiness, producing larger parasites with less disposition to
contract, but the fourth and fifth cultures were encreasingly poor.
Inoculation with these cultures failed to produce the disease. To
explain this the doctrine of passive germs, strong for survival, but
weak pathogenically, is hazarded.
To summarize, the successive stages of the piroplasma are: 1st. The
intraglobular _pear-shaped bodies_, with flagellum often connecting two
bodies. 2nd. The _rounded bodies with refrangent nucleus_—intraglobular
or extraglobular. 3d. The _free round bodies_ with the nucleus divided
into 2 to 5 _chromatin masses_. 4th. The _free chromatin masses_, large,
_active_, _infecting germs_, and small, _passive_, _noninfecting germs_.
The insuccess of inoculations of cattle with the last-named bodies
throws an air of doubt upon them as links in the pathogenic chain.
Definite information on the antecedents, environment, food, etc., of the
cattle unsuccessfully inoculated, including the season, shelter and
meteorological conditions might have brought us a step nearer to the
full life history of the piroplasma.
_The Cattle Tick_: _Boöphilus Bovis_: _Ixodes Bovis_: _I. Dugesii_: _The
Invertebrate Host of the Texas Fever Organism_. As early as 1868 shrewd
observers had noticed that in all outbreaks of Texas fever the affected
animals were covered with ticks, and drew the natural inference that the
disease was due to the bites of these insects. But the prevalence of
ticks in localities where the disease was unknown served to draw
attention away from the important fact that was suggestive of the true
explanation of the disease. The truth, however, constantly obtruded
itself that casual cases were never found in the absence of the tick.
Finally, in 1889, Kilborne conceived the idea of putting the matter to
the test, and with the approval of the Chief of the Bureau of Animal
Industry, set aside special paddocks for this purpose. Five native
cattle were placed, at midsummer, with three South Carolina cattle, from
which all ticks had been carefully picked, and they completely escaped
infection.
After seventy-one days, on September 6th, when the hottest weather had
passed, two were turned into a lot with four South Carolina cattle of
the original herd which had stocked the pasture with ticks. Of the two
one died of Texas fever, September 20th, and the other sickened in the
last week of September, and had a relapse in October, but finally
recovered. Of eleven other native cattle placed in this tick-infested
field up to September 30th, ten sickened and one escaped. One animal
placed in the field October 19th escaped.
Again three North Carolina cattle and three natives were placed in a
field September 14th and 15th. The new generation of ticks was retarded
by the cool season, so that few larvæ appeared on the native stock yet
one of the three sickened.
These results were confirmed by a series of other similar experiments.
In a further experiment, September 13th, thousands of ticks, mostly
mature, from North Carolina, were scattered over a second lot and four
native cattle turned into it next day. Three sickened and one, to
outward appearance, escaped.
These results were corroborated by experiments made in succeeding years.
In addition the disease was produced regularly in native stock by
placing on their skin the six-legged larvæ of boöphilus bovis, which had
been hatched in glass vessels in the laboratory. It was also shown that
the Washington winter destroyed the ticks in infected pastures so that
native cattle could be safely turned on them the following spring or
summer.