ounces of whisky or half an ounce of carbonate of ammonia. Prevent the
animal from getting up too soon, or the attack may immediately recur.
Afterwards, if the attack was due to weakness from loss of blood,
impoverished blood, or associated with debility, general tonics, rest,
and nourishing food are indicated.
HYPERTROPHY OF THE HEART, OR CARDIAC ENLARGEMENT.
Hypertrophy of the heart implies augmentation of bulk in its muscular
substance, with or without dilatation or contraction of its cavities. It
may exist with or without other cardiac affections. In valvular disease
or valvular insufficiency hypertrophy frequently results as a
consequence of increased demand for propelling power. The difficulties
with which it is most frequently connected are dilatation and
ossification of the valves. It may also occur in connection with
atrophied kidneys, weak heart, etc. It may be caused by an increased
determination of blood to the organ or from a latent form of
myocarditis, and it may arise from a long-continued increase of action
dependent upon nervous disease. All the cavities of the heart may have
their walls hypertrophied or the thickening may involve one or more.
While the wall of a ventricle is thickened, its cavity may retain its
normal size (simple hypertrophy) or be dilated (eccentric hypertrophy),
or it may be contracted (concentric hypertrophy). Hypertrophy of both
ventricles increases the length and breadth of the heart. Hypertrophy of
the left ventricle alone increases its length; of the right ventricle
alone increases its breadth toward the right side. Hypertrophy with
dilatation may affect the chambers of the heart conjointly or
separately. This form is by far the most frequent variety of cardiac
enlargement. When the entire heart is affected, it assumes a globular
appearance, the apex being almost obliterated and situated transversely
in the chest. The bulk may become three or four times greater than the
average heart.
_Symptoms._--In hypertrophy of the heart, in addition to the usual
symptoms manifested in organic diseases of the heart, there is a
powerful and heaving impulse at each beat, which may be felt on the left
side, often also on the right. These pulsations are regular, and when
full and strong at the jaw there is a tendency to active congestion of
the capillary vessels, which frequently give rise to local inflammation,
active hemorrhage, etc. If the pulse is small and feeble at the jaw, we
may conclude that there is some obstacle to the escape of the blood from
the left ventricle into the aorta, which has given rise to the
hypertrophy. In case of hypertrophy with dilatation, the impulse is not
only powerful and heaving, but it is diffused over the whole region of
the heart, and the normal sounds of the heart are greatly increased in
intensity. Percussion reveals an enlarged area of dullness, while the
impulse is usually much stronger than normal.
Dropsy of the pericardium will give the same wide space of dullness, but
the impulse and sound are lessened. An animal with a moderate degree of
enlargement may possibly live a number of years and be capable of
ordinary work; it depends largely upon concomitant disease. As a rule,
an animal affected with hypertrophy of the heart will soon be
incapacitated for work, and becomes useless and incurable.
_Treatment._--If the cause can be discovered and is removable, it should
be done. The iodid of potassium, in cases of valvular thickening, may be
of some benefit if continued for a sufficient length of time; it may be
given in 2-dram doses, twice a day, for a month or more. The tincture of
digitalis may be given, in cases where the pulse is weak, in doses of 2
teaspoonfuls three times daily. This remedy should not be continued if
the pulse becomes irregular. General tonics, freedom from excitement or
fatigue, avoidance of bulky food, good ventilation, etc., are indicated.
DILATATION OF THE HEART.
This is an enlargement, or stretching, of the cavities of the heart, and
may be confined to one or extend to all. Two forms of dilatation may be
mentioned--simple dilatation, where there is normal thickness of the
walls, and passive, or attenuated, dilatation, where the walls are
simply distended or stretched out without any addition of substance.
_Causes._--Any cause producing constant and excessive exertion of the
heart may lead to dilatation. Valvular disease is the most frequent
cause. General anemia predisposes to it by producing relaxation of
muscular fiber. Changes in the muscular tissue of the heart walls,
serous infiltration from pericarditis, myocarditis, fatty degeneration
and infiltration, and atrophy of the muscular fibers may all lead to
dilatation.
_Symptoms._--The movements of the heart are feeble and prolonged, a
disposition to staggering or vertigo, dropsy of the limbs, very pale or
very dark-colored membranes, and difficult breathing on the slightest
excitement.
_Treatment._--General tonics, rich feed, and rest.
FATTY DEGENERATION OF THE HEART.
Fatty degeneration may involve the whole organ, or may be limited to its
walls, or even to circumscribed patches. The latter is situated at the
exterior, and gives it a mottled appearance. When generally involved it
is flabby or flaccid, and in extreme cases collapses when emptied or
cut. Upon dissection the interior of the ventricles is observed to be
covered with buff-colored spots of a singular zigzag form. This
appearance may be noticed beneath the pericardium, and pervading the
whole thickness of the ventricular walls, and in extreme cases those of
the fleshy columns in the interior of the heart. These spots are found
to be degenerated muscular fibers and colonies of oil globules. Fatty
degeneration is often associated with other morbid conditions of the
heart, such as obesity, dilatation, rupture, aneurism, etc. It may be
connected with fatty diseases of other organs, such as the liver,
kidneys, etc. When it exists alone its presence is seldom suspected
previous to death. It may be secondary to hypertrophy of the heart, to
myocarditis, or to pericarditis. It may be due to deteriorated
conditions of the blood in wasting diseases, excessive hemorrhages,
etc., or to poisoning with arsenic and phosphorus.
_Symptoms._--The most prominent symptoms of fatty degeneration are a
feeble action of the heart, a remarkably slow pulse, general debility,
and attacks of vertigo. It may exist for a long time, but is apt to
terminate suddenly in death upon the occurrence of other diseases,
surgical operations, etc. It may involve a liability to sudden death
from rupture of the ventricular walls.
_Treatment._--Confinement in feed to oats, wheat or rye bran, and
timothy hay. Twenty drops of sulphuric acid may be given in drinking
water three times a day, and hypophosphite of iron in 2-dram doses,
mixed with the feed, twice a day. Other tonics and stimulants as they
may be indicated.
RUPTURE OF THE HEART.
This may occur as the result of some previous disease, such as fatty
degeneration, dilatation with weakness of the muscular walls, etc. It
may be caused by external violence, a crushing fall, pressure of some
great weight, etc. Usually death follows a rupture very quickly, though
an animal may live for some time when the rent is not very large.
WEAKNESS OF THE HEART.
This may arise from general debility, the result of exhausting disease,
overwork, or heart strain, or loss of blood. It is indicated by a small,
feeble, but generally regular pulse, coldness of the body, etc.
Treatment should be directed to support and increase the strength of the
animal by tonics, rest, and nutritious feed. Carbonate of ammonia may be
given to stimulate the heart's action and to prevent the formation of
heart clot.
CONGESTION OF THE HEART
Congestion, or an accumulation of the blood in the cavities of the
heart, may occur in consequence of fibrinous deposits interfering with
the free movements of the valves, usually the product of endocarditis or
as a result of excessive muscular exertion.
Symptoms are great difficulty of breathing, paleness of the visible
mucous membranes, great anxiety, frequently accompanied by a general
tremor and cold perspiration, followed by death. It usually results in
death very quickly.
CYANOSIS OF NEWBORN FOALS.
This is a condition sometimes found in foals immediately after birth,
and is due to nonclosure of the foramen ovale, which allows a mixture of
the venous with the arterial blood in the left cavities of the heart. It
is characterized by a dark purple or bluish color of the visible mucous
membranes, shortness of breath, and a general feebleness. Foals thus
affected generally live only a few hours after birth.
DISEASES OF ARTERIES, OR ARTERITIS AND ENDARTERITIS.
Inflammation of arteries is rarely observed in the horse as a primary
affection. Direct injuries, such as blows, may produce a contusion and
subsequent inflammation of the wall of an artery; severe muscular strain
may involve an arterial trunk; hypertrophy of the heart, by increasing
arterial tension, may result in the production of a general
endarteritis. Septic infection may affect the inner coat and ultimately
involve all three, or it may be the result of an inflammation in the
vicinity of the vessels, etc. Inflammation of arteries, whatever the
cause may be, often leads to very serious results in the development of
secondary changes in their walls. Arteritis may be acute, subacute, or
chronic; when the inner coat alone is affected it is known as
endarteritis.
_Symptoms._--Arteritis is characterized by a painful swelling along the
inflamed vessel, throbbing pulse, coldness of the parts supplied by the
inflamed vessel, sometimes the formation of gangrenous sloughs,
suppuration, abscess, etc. In an inflammation of the iliac arteries we
find coldness and excessive lameness or paralysis of one or both hind
limbs.
_Pathology._--In acute arteritis we find swelling along the vessel, loss
of elasticity, friability, and thickening of the walls; a roughness and
loss of gloss of the inner coat, with the formation of coagula or pus in
the vessel. Subacute or chronic arteritis may affect only the outer coat
(periarteritis), both the outer and middle coat, or the inner coat alone
(endarteritis); and by weakening the respective coats leads to rupture,
aneurism, or to degenerations, such as bony, calcareous, fatty,
atheromatous, etc. It may also lead to sclerosis or increase of fibrous
tissue, especially in the kidneys, when it may result in the condition
known as arterio-capillary fibrosis. Chronic endarteritis is fruitful in
the production of thrombus and atheroma. Arteritis may be limited to
single trunks or it may affect, more or less, all the arteries of the
body. Arteries which are at the seat of chronic endarteritis are liable
to suffer degenerative changes, consisting chiefly of fatty
degeneration, calcification, or the breaking down of the degenerated
tissue, and the formation of erosions or ulcerlike openings in the inner
coat. These erosions are frequently called atheromatous ulcers, and
fragments of tissue from these ulcers may be carried into the
circulation, forming emboli. Fibrinous thrombi are apt to form upon the
roughened surface of the inner coat or upon the surface of the erosions.
Fatty degeneration and calcification of the middle and outer coats may
occur, and large, hard, calcareous plates project inward, upon which
thrombi may form or may exist in connection with atheroma of the inner
coat. When there is much thickening and increase of new tissue in the
wall of the affected artery it may encroach upon the capacity of the
vessel, and even lead to obliteration. This is often associated with
interstitial inflammation of glandular organs.
_Treatment._--Carbonate of potassium in 1-dram doses, to be given in 4
ounces liquor acetate of ammonia every six hours; scalded bran
sufficient to produce loosening of the bowels, and complete rest;
externally, applications of hot water or hot hop infusion.
ATHEROMA.
Atheroma is a direct result of an existing chronic endarteritis, the
lining membrane of the vessels being invariably involved to a greater or
less degree. It is most frequently found in the arteries, although the
veins may develop an atheromatous condition when exposed to any source
of prolonged irritation. Atheroma may affect arteries in any part of the
body; in some instances almost every vessel is diseased, in others only
a few, or even parts of one vessel. It is a very common result of
endocarditis extending into the aorta, which we find perhaps the most
frequent seat of atheroma. As a result of this condition the affected
vessel becomes impaired in its contractile power, loses its natural
strength, and, in consequence of its inability to sustain its accustomed
internal pressure, undergoes in many cases dilatation at the seat of
disease, constituting aneurism. In an atheromatous vessel, calcareous
deposits soon occur, which render it rigid, brittle, and subject to
ulceration or rupture. In such vessels the contractility is destroyed,
the middle coat atrophied and beyond repair. Atheroma in the vessels of
the brain is a frequent cause of cerebral apoplexy. No symptoms are
manifested by which we can recognize this condition during life.
CONSTRICTION OF AN ARTERY.
This is usually the result of arteritis, and may partly or wholly be
impervious to the flow of blood. When this occurs in a large vessel it
may be followed by gangrene of the parts; usually, however, collateral
circulation will be established to nourish the parts previously supplied
by the obliterated vessel. In a few instances constriction of the aorta
has produced death.
ANEURISM.
Aneurism is usually described as true or false. True aneurism is a
dilatation of the coats of an artery over a larger or smaller part of
its course. Such dilatations are usually due to chronic endarteritis and
atheroma. False aneurism is formed after a puncture of an artery by a
dilatation of the adhesive lymph by which the puncture was united.
_Symptoms._--If the aneurism is seated along the neck or a limb it
appears as a tumor in the course of an artery and pulsating with it. The
tumor is round, soft, and compressible, and yields a peculiar
fluctuation upon pressure. By applying the ear over it a peculiar
purring or hissing sound may sometimes be heard. Pulsation, synchronous
with the action of the heart, is the diagnostic symptom. It is of a
slow, expansive, and heavy character, as if the whole tumor were
enlarging under the hand. Aneurisms seated internally may occupy the
cavity of the cranium, chest, or abdomen. As regards the first, little
is known during life, for all the symptoms which they produce may arise
from other causes. Aneurism of the anterior aorta may be situated very
closely to the heart or in the arch, and it is very seldom that we can
distinguish it from disease of the heart. The tumor may encroach upon
the windpipe and produce difficulty in breathing, or it may produce
pressure upon the vena cava or the thoracic duct, obstructing the flow
of blood and lymph. In fact, whatever parts the aneurism may reach or
subject to its pressure, may have their functions suspended or
disturbed. When the tumor in the chest is large, we generally find much
irregularity in the action of the heart; the superficial veins of the
neck are distended, and there is usually dropsical swelling under the
breast and of the limbs. There may be a very troublesome cough without
any evidence of lung affection. Sometimes pulsation of the tumor may be
felt at the lower part of the neck where it joins the chest. When the
aneurism occurs in the posterior aorta no diagnostic symptoms are
appreciable; when it occurs in the internal iliac arteries an
examination per rectum will reveal it.
There is one form of aneurism which is not infrequently overlooked,
affecting the anterior mesenteric artery, primarily induced by a
worm--_Strongylus vulgaris_. This worm produces an arteritis, with
atheroma, degeneration, and dilatation of the mesenteric arteries,
associated with thrombus and aneurism. The aneurism gives rise to colic,
which appears periodically in a very violent and often persistent type.
Ordinary colic remedies have no effect, and after a time the animal
succumbs to the disease. In all cases of animals which are habitually
subject to colicky attacks, parasitic aneurism of the anterior
mesenteric artery may be suspected. (See p. 92.)
_Pathology._--Aneurisms may be diffuse or sacculated. The diffuse
consists in a uniform dilatation of all the coats of an artery, so that
it assumes the shape of a cylindrical swelling. The wall of the aneurism
is atheromatous, or calcified; the middle coat may be atrophied. The
sacculated, or circumscribed, aneurism consists either in a dilatation
of the entire circumference of an artery over a short portion of its
length, or in a dilatation of only a small portion of one side of the
wall. Aneurism may become very large; as it increases in size it presses
upon and causes the destruction of neighboring tissues. The cavity of
the aneurismal sac is filled with fluid or clotted blood or with layers
of fibrin which adhere closely to its wall. Death is produced usually by
the pressure and interference of the aneurism with adjoining organs or
by rupture. In worm aneurism we usually find large thrombi within the
aneurismal dilatation of the artery, which sometimes plug the whole
vessel or extend into the aorta. Portions of this thrombus, or clot, may
be washed away and produce embolism of a smaller artery. The effect in
either case is to produce anemia of the intestinal canal, serous or
bloody exudation in its walls, which leads to paralysis of the intestine
and resultant colicky symptoms.
_Treatment._--The only treatment advisable is to extirpate or ligate the
tumor above and below.
RUPTURE OF AN ARTERY.
Endarteritis, with its subsequent changes in the walls of arteries, is
the primary cause of rupture in the majority of instances. The rupture
may be partial, involving only one or two coats, and will then form an
aneurism. If complete, it may produce death when it involves a large
vessel, especially if it is situated in one of the large cavities
permitting an excessive escape of blood. Rupture may be produced by
mechanical violence or accident.
_Symptoms._--In fatal rupture, associated with profuse bleeding, the
animal becomes weak, the visible mucous membranes become blanched, the
breathing hurried or gasping, pupils dilated, staggering in gait,
syncope, death. When the hemorrhage is limited the symptoms may not
become noticeable; if it is near the surface of the body a round or
diffuse swelling or tumor may form, constituting a hygroma. If the
rupture is associated with an external wound, the bleeding artery should
be ligated, or where a bandage is applicable, pressure may be applied
by tight bandaging. As a secondary result of rupture of an artery we may
have formation of abscess, gangrene of a part, etc.
_Treatment._--When rupture of a deep-seated artery is suspected, large
doses of fluid extract of ergot may be given to produce contraction of
the blood vessels. Tannin and iron are also useful. The animal should be
allowed to have as much water as he desires. Afterwards stimulants and
nourishing feed are indicated.
THROMBUS AND EMBOLISM.
By thrombosis is generally understood the partial or complete closure of
a vessel by a morbid product developed at the site of the obstruction.
The coagulum, which is usually fibrinous, is known as a thrombus. The
term "embolism" designates an obstruction caused by any body detached
and transported from the interior of the heart or of some vessel.
Thrombi occur as the result of an injury to the wall of the vessel or
may follow its compression or dilatation; they may result from some
alteration of the wall of the vessel by disease or by the retardation of
the circulation. These formations may occur during life, in the heart,
arteries, veins, or in the portal system. When a portion of fibrin
coagulates in one of the arteries and is carried along by the
circulation, it will be arrested, of course, in the capillaries, if not
before; when in the veins, it may not be stopped until it reaches the
lungs; and when in the portal system the capillaries of the liver will
prevent its further progress. The formation of thrombi may act primarily
by causing partial or complete obstruction, and, secondarily, either by
larger or smaller fragments becoming detached from their end and by
being carried along by the circulation of the blood to remote vessels,
embolism; or by the coagulum becoming softened and converted into pus,
constituting suppurative phlebitis. These substances occur most
frequently in those affections characterized by great exhaustion or
debility, such as pneumonia, purpura hemorrhagica, endocarditis,
phlebitis, puerperal fever, hemorrhages, etc. These concretions may form
suddenly and produce instantaneous death by retarding the blood current,
or they may arise gradually, in which case the thrombi may be organized
and attached to the walls of the heart, or they may soften, and
fragments of them (emboli) may be carried away. The small, wartlike
excrescences occurring sometimes in endocarditis may occasionally form a
foundation on which a thrombi may develop.
_Symptoms._--When heart clot, or thrombus, exists in the right side, the
return of blood from the body and the aeration in the lungs is impeded,
and if death occurs, it is owing to syncope rather than to strangulation
in pulmonary respiration. There will be hurried and gasping breathing,
paleness and coldness of the surface of the body, a feeble and
intermittent or fluttering pulse, and fainting. When a fibrinous
coagulum is carried into the pulmonary artery from the right side of the
heart, the indications are a swelling and infiltration of the lungs and
pulmonary apoplexy. When the clot is situated in the left cavities of
the heart or in the aorta, death, if it occurs, takes place either
suddenly or at the end of a few hours from coma.
_Pathology._--When a coagulum is observed in the heart it may become a
question whether it was formed during life or after death. The loose,
dark coagula so often found after death are polypi. If the deposition
has taken place during the last moments of life, the fibrin will be
isolated and soft, but not adherent to the walls; if it be isolated,
dense, and adherent or closely intertwined with the muscles of the
papillae and tendinous cords, the deposition has occurred more or less
remote from the act of dying. Occasionally the fibrin may be seen lining
one of the cavities of the heart, like a false endocardium, or else
forming an additional coat to the aorta or other large vessels without
producing much obstruction. Thrombi, in some instances, soften in their
centers, and are then observed to contain a puslike substance. If this
softening has extended considerably, an outer shell, or cyst, only may
remain. The sources of danger exist not only in the interruption of the
circulation of the blood, but also in a morbid state of the system,
produced by the disturbed nutrition of a limb or organ, as well as the
mingling of purulent and gangrenous elements with the blood.
_Treatment._--The urgent symptoms should be relieved by rest,
stimulants, and the use of agents which will act as solvents to the
fibrinous clots. Alkalis are specially useful for this purpose.
Carbonate of ammonia may be administered in all cases of thrombus, and
should be continued for a long time in small doses several times a day.
In cases of great debility associated with a low grade of fever,
stimulants and tonics, and nitro-muriatic acid as an antiseptic, may be
beneficial.
DISEASES OF VEINS, OR PHLEBITIS.
Inflammation of veins may be simple or diffuse. In simple phlebitis the
disease of the vein is confined to a circumscribed or limited portion of
a vein; in diffuse it involves the vein for a long distance; it may even
extend from a limb or foot to the heart.