and enveloping the lungs. It is somewhat rare as an independent disease,
but it often complicates pneumonia; indeed, it is often caused by the same
germ that causes pneumonia--pneumococcus. It may arise from exposure to
cold or wet or from external violence, and is usually present in some
degree in cases in which the ribs have been fractured with or without a
penetrated wound.
_Symptoms._--In the first stage there is great pain aggravated by movement,
and the animal is usually stiff as though foundered, the pulse is quick and
hard, the breathing abdominal, the chest being fixed so far as possible,
the inspiration short and jerky, the expiration longer. The pain is caused
by the friction of the dry, inflamed pleural surfaces of the lung and chest
on each other. At this stage the ear detects a dry friction murmur,
resembling somewhat the sound made by rubbing two pieces of sole leather
together. Pressure between the ribs gives pain and usually causes the
animal to flinch and grunt. The muzzle is hot and dry, the mouth slimy, and
the secretions scanty. After a day or two the severity of the symptoms is
much lessened, the temperature, which during the first days may have been
as high as 106∞ F., falls to 103∞ or 104∞, the pain decreases, the
stiffness disappears, and the patient eats a little. The pulse softens, but
remains quicker than normal. Now, day by day the patient loses a little
strength, the friction sound disappears as the exudation moistens the
pleural surfaces; percussion now shows a horizontal line of dullness, which
day by day rises higher in the chest, the respiration grows more frequent
and labored, the countenance is anxious and haggard, the eyes sink somewhat
in their sockets, and in unfavorable cases death occurs during the second
or third week, from either asphyxia or heart failure.
In pleurisy, as in pneumonia, the elbows are usually turned outward. Care
must be taken to differentiate pleurisy from traumatic pericarditis (which
see). In the latter condition the area of dullness of the heart is much
increased, and usually a splashing sound is heard at each beat of the
heart. Another diagnostic symptom of value is that in traumatic
pericarditis respiration is painful, not difficult, and the respiratory
rate is very much increased on movement. In both conditions a considerable
swelling of the dewlap may be noticed in the later stages.
_Treatment._--Give the same general care as recommended in bronchitis or
pneumonia. In the early stages give a febrifuge to reduce the fever, as
directed for pneumonia. For relief of the cough give electuary formula,
which will be found in the treatment of laryngitis. The bowels must be kept
relaxed and the kidneys secreting freely. In the stage of effusion the
following should be given three times daily: Digitalis tincture, 1 ounce;
iodid of potassium, 30 to 60 grains; mix. Apply strong counterirritant to
chest and put seton in dewlap. (See "Setoning," p. 293.) If collapse of the
lung is threatened, a surgical operation, termed paracentesis thoracis, is
sometimes performed; this consists in puncturing the chest cavity and
drawing off a part of the fluid. The instruments used are a small trocar
and cannula, which are introduced between the eighth and ninth ribs. The
skin should be drawn forward so that the external wound may not correspond
to the puncture of the chest, to prevent the entrance of air. Only a
portion of the fluid should be removed. The animal gets immediate relief,
but it is generally only temporary, as the fluid has a tendency to
accumulate again.
PNEUMONIA.
Pneumonia is an inflammation of the lung substance, and is divided into
three forms, viz, croupous, catarrhal, and interstitial. These various
forms, however, can be differentiated only by the expert, and it is
therefore deemed necessary for the purpose of the present work to treat the
subject under the general head of pneumonia.
The causes of pneumonia in general are the same as those of the various
other inflammatory diseases of the respiratory tract. The germ is known as
a pneumococcus. The disease mostly follows congestion of the lungs, but may
in rare cases have a parasitic origin.
_Symptoms._--In the first stage, that of congestion, the disease is usually
ushered in by a chill, although this may not always be observed by the
attendant. This is followed by an elevation of temperature, usually 105∞ to
106∞ F., or it may be even higher. The respirations are quick and shallow;
the nostrils are dilated; the pulse is full and hard. Cough may or may not
appear in this stage. The nose is hot and dry; the tongue sometimes
protrudes and is slimy; the coat is staring, and the skin dry and harsh.
The urine is usually diminished in quantity, high colored, and the bowels
constipated. The animal stands with the forelegs wide apart to facilitate
respiration. On auscultation crepitation will be observed over the portion
of the lung affected. The sounds elicited on percussion are practically
normal in this stage.
In the second stage the temperature generally drops one or two degrees, and
respiration is performed with much difficulty. The cough is frequent and
painful. The animal still stands with the forelegs wide apart and the
elbows turned outward. If it assumes the recumbent position it rests on the
sternum. All secretions are more or less suspended, particularly the milk
in cows. The animal has a haggard appearance, and the pulse becomes small
and wiry at this period. The extremities are hot and cold alternately; the
crepitation which was present in the first stage is now absent, and no
sound on auscultation is heard, unless it is a slight wheezing or whistling
noise. On percussion dullness over the diseased lung is manifested,
indicating consolidation. The lung has now assumed a characteristic
liverlike appearance.
In the third stage, if the disease is to terminate favorably, the cough
becomes loose, the animal improves, the appetite returns, and the symptoms
above detailed rapidly subside; if, on the other hand, resolution is not
progressing, the lung substance degenerates, becomes clogged up, and ceases
to function. In fatal cases the breath has a peculiar, fetid, cadaverous
odor, and is taken in short gasps; the horns, ears, and extremities become
cold and clammy, and the pulse is imperceptible. On auscultation, when
suppuration is taking place and the lung structure is breaking down, a
bubbling or gurgling crepitation, caused by the passage of air through pus,
is heard.
_Treatment._--Good hygienic surroundings and good nursing are essential in
connection with the medical treatment. The probability of recovery depends
largely on the extent of the lung tissue involved, as well as on the
intensity of the inflammatory process. In the early stage, when the fever
is high, febrifuges should be given. If the pulse be strong and full,
aconite (Fleming's tincture, 1 to 2 drams, every four or five hours) may be
given for a short time, but should be discontinued as soon as the fever
begins to abate. Aconite is a valuable drug in the hands of the intelligent
practitioner, but my experience leads me to believe that not infrequently
animals are lost by its injudicious use, for in many febrile conditions it
is positively contraindicated, owing to its action upon the heart. In a
plethoric animal, with a strong, bounding pulse, bleeding may be resorted
to instead of administering aconite. If the bowels are constipated,
calomel, 1 to 3 drams, which acts as a cathartic and a febrifuge, is
advisable. In the second stage diffusible stimulants are required, viz:
Spirits of nitrous ether, 2 ounces; aromatic spirits of ammonia, 1 ounce;
mix, and give in gruel three times daily. In some cases carbonate of
ammonia, 2 to 5 drams, has been found beneficial. Most practitioners apply
counterirritants, such as mustard plasters, turpentine, and ammonia
liniment, or cantharides.
EMPHYSEMA (HEAVES).
Emphysema is a rupture of the minute air vesicles of the lung substance,
and may be either interlobular or vesicular. There is an extreme
interference with respiration, inspiration being short and expiration
prolonged. It is a nonfebrile condition, in which the appetite is not
decreased and the milk secretion is kept up. It may be caused by an attack
of asthma or may result from chronic bronchitis. The disease can be
diagnosed by the marked interference with respiration. The animal, as a
rule, is emaciated, has a staring coat, and is hidebound. If percussion is
resorted to, the animal's chest will give a tympanic, drumlike sound. The
normal resonant sound is exaggerated.
_Treatment._--The disease is incurable, and only a palliative form of
treatment can be carried out. The destruction of the animal is often
advisable, from a humane as well as from a financial point of view.
PULMONARY CONGESTION.
Cattle that are overdriven or overworked are liable to pulmonary congestion
in an acute form, and sometimes to pulmonary apoplexy. In such cases they
should be allowed to rest, and if the weather is hot, they should be put in
a shady place. Give stimulants internally, unload the venous side of the
heart by bleeding, and apply stimulating applications to the legs, and
bandage.
HEMOPTYSIS.
Hemoptysis is a term used to signify bleeding from the lungs. The trouble
may result from a previous congestion of the lungs or from a breaking down
of the lung substance, or from specific disorders.
Bleeding from the lungs comes from both nostrils and from the mouth. The
blood is bright red, frothy, and accompanied with a cough, the flow being
somewhat profuse and intermingled with mucus. It may cease of its own
accord. Internally hemostatics are indicated, and locally over the sides
cold applications have a tendency to check the hemorrhage. A drench of
1-1/2 drams of gallic acid dissolved in a pint of water should be given.
ABSCESS OF THE LUNG.
Abscesses of the lung sometimes form during the course of or subsequent to
tuberculosis or other diseases. An animal affected with abscess of the lung
usually has a protracted, feeble cough and a general appearance of
emaciation and anemia. The pulse is feeble and the breath foul. An
offensive discharge from the lungs frequently occurs. Percussion and
auscultation aid in making a diagnosis in this condition. The appetite is
poor. Such animals go from bad to worse, and their prompt destruction
would, as a rule, be to the interest of the owner.
HYDROTHORAX.
Hydrothorax, or dropsy of the chest, is not a disease in itself, but is
simply a condition in which an effusion takes place in the chest cavity,
and is the result or effect of some disease, mostly pleurisy. It can be
easily diagnosed by physical signs. A loss of the respiratory murmur will
be noticed on auscultation, and on percussion dullness or flatness on a
line as high as the effusion has taken place. When a large amount of
effusion is present, tapping with the trocar and cannula is generally
resorted to. The proper method of performing this operation will be found
under the head of "Pleurisy."
PNEUMOTHORAX.
An accumulation of gas in the pleural sac is known as pneumothorax. The
presence of air may result from either an injury of the lung or a wound
communicating from the exterior. The indications for treatment are to
remove any foreign body that may have penetrated, to exclude the further
entrance of the air into the cavity by the closure of the external opening,
and to employ antiseptics and adhesive dressings. The air already in the
cavity will in most cases be absorbed.
VERMINOUS BRONCHITIS.
This is a disease that sometimes attacks young cattle when pastured in
low-lying meadows near rivers subject to flood. It is caused by a small
worm, _Strongylus micrurus_, which lodges in large numbers in the trachea
and bronchial tubes, giving rise to considerable irritation of the air
passages and inflammation. Sometimes the strongyles lodge in large numbers
in the windpipe, forming themselves into a ball, and thus choke the animal
to death.
_Symptoms._--It is liable to attack a number of animals at once, and the
weakest are the first to give way. The animal has a remarkably forcible
cough, distressing, and of a special hacking and paroxysmal character. A
stringy mucus is sometimes expelled during the spells of coughing. This
mucus contains the _Strongylus micrurus_, which can be detected, or their
ova observed, under a low power of the microscope. The attack has a
subacute character and is very exhausting. The parasites, by becoming
entwined in balls, seriously impede respiration, which is always remarkably
labored in this disease.
_Treatment._--The affected calves should be placed in a dry stable,
protected from dampness, and subjected to fumigations of sulphurous
anhydrid or chlorin gas. The liberation of chlorin gas is brought about by
the action of sulphuric acid, either on a mixture of chlorid of sodium and
black oxid of manganese or on bleaching powder. Sulphurous anhydrid may be
procured by burning sulphur. Some practitioners prescribe small doses of
spirits of turpentine in linseed oil. The system requires good support, and
the diet should therefore be liberal and nutritious. Equal parts of
sulphate of iron, gentian, and ginger make an excellent tonic.
_Prevention._--Avoid pastures notorious for generating verminous
bronchitis.
PLEURODYNIA.
Pleurodynia is a term applied to rheumatism of the intercostal muscles, the
apparent symptoms being very similar to those of pleurisy. The animal is
stiff, is not inclined to turn around, and the ribs are kept in a fixed
state as much as possible. Pleurodynia may be distinguished from pleurisy
by the coexistence of rheumatism in other parts and by the comparative
absence of fever, cough, the friction sound, and the effusion into the
chest. The treatment for this affection is the same as that for rheumatism
affecting other parts.
DISEASES OF THE NERVOUS SYSTEM.
By W. H. HARBAUGH, V. S.
[Revised by John E. Mohler, V. M. D.]
THE NERVOUS SYSTEM.
The nervous system is the distinguishing feature of animal life. Without it
there can be no intelligence, no instinct, no sensibility, no perception;
in fact, existence would be nothing more than vegetable life.
The senses--touch, taste, sight, hearing, smell--all depend on the nervous
system. Motion depends on it. A muscle can not contract without receiving
the stimulus from the nervous system. For example, if a nerve passing from
a nerve center to a muscle is severed, the particular muscle that is
supplied by the cut nerve is paralyzed.
The nervous system is often studied in two divisions--the cerebrospinal
division and the sympathetic division.
The cerebrospinal division consists of the brain and spinal cord, nerves,
and ganglia. The nerves of this division convey the impulses of motion and
sensation and supply all parts which are under the control of the will. For
example, the voluntary muscular tissue includes all the muscles which act
as the will directs. Another example: If anything comes in contact with any
part of the skin, the impression is immediately perceived. All the special
senses belong to this division.
The sympathetic division consists of nerves and ganglia. The muscular
tissue, which acts independently of the will--as, for example, the stomach,
intestines, womb, blood vessels, ducts, etc.--is called involuntary
muscular tissue, and receives nervous stimulus from the sympathetic
division.
The brain, spinal cord, and the ganglia are the central organs of the
nervous system. The nerves conduct the nervous influence. The nerves
terminate differently according to their function. The terminations are
called end organs. The terminal end organs in the skin and other parts
endowed with sensation receive the impressions, which are conveyed to the
brain, where they are appreciated. They are so sensitive that the most
gentle zephyr is perceived. They are so abundant that the point of the
finest needle can not pierce the skin without coming in contact with them,
and the sensation of pain is instantly conveyed to the brain. The terminal
end organs of the nerves that supply the muscles are different, as they
give the impulse which is conveyed by the motor nerves to the elements
which constitute the muscle, and this impulse is the excitation which
causes the muscle to contract. The terminal end organs of the special
senses of taste, smell, etc., receive their special impressions, and their
respective nerves carry the impressions to the brain.
There are two divisions of nerves, the afferent and efferent.
The afferent nerves are those which convey the impression to the nerve
centers. All the sensory nerves belong to this division.
The efferent nerves are those which convey the nervous impulse outward from
the nerve centers, and they are further classified according to the
function of their respective centers. For example: Motor fibers carry the
impulse from the nerve center to a muscle to cause contraction. Vasomotor
fibers carry the impulse to the muscular tissue in the blood vessels, which
regulates their caliber. The secretory fibers convey the impulse to the
cells of the glands and excite the activity of the gland, and its
particular product is secreted or evolved, as, for instance, milk in the
mammary gland. Inhibitory fibers control or inhibit the action of the organ
to which they are distributed, as, for instance, the heart.
Nerve centers may be considered as a collection or group of nerve cells.
Both the cerebrospinal and the sympathetic divisions have nerve centers.
The centers derive their special names from their functions. The brain is
the great center of the nervous system, as it is the center of intelligence
and perception. The centers of all the special senses, as well as the
centers of various functions, are located in different parts of the brain.
Nerve centers also exist in the spinal cord and in connection with the
sympathetic system.
A nerve is a cord consisting of a certain number of fibers of nerve tissue,
inclosed in a sheath of connective tissue. Nerves divide and subdivide,
sending off branches, which ramify in all parts of the body, and, as they
near their terminations, they contain but one or two fibers.
The brain and spinal cord are contained within a bony canal, which forms a
protective covering for them.
The spinal cord, or spinal marrow, lodged within the spinal canal, or
hollow of the backbone, is continuous with the brain anteriorly, and
terminates in a point in the sacrum (that part of the spinal column which
immediately precedes the tail). The spinal cord gives off branches at each
of the spaces between the segments of the backbone. These branches form
nerve trunks which carry both sensory and motor impressions and impulses.
The spinal cord is a grand nerve trunk to carry messages to or from the
brain and to and from the reflex centers contained within itself.
The brain is contained within the cavity of the skull and is continuous
with the spinal cord; there is nothing to mark the place where one leaves
off and the other begins. The brain is the seat of reason and intelligence.
Voluntary effort originates from the brain. Coordination, or harmony of
movement, is controlled by the rear portion of the brain, known as the
cerebellum.
The meninges are the membranes, three in number, which envelop the brain
and spinal cord, and separate them from the bones which form the walls of
the cranial cavity and spinal canal.
The sympathetic, also called the ganglionic, division of the nervous system
consists of two chains of ganglia, reaching from the head to the tail,
situated beneath the spinal column, one on either side. The presence of the
ganglia or enlargements on the cords give them their chainlike appearance.
The sympathetic nerves are closely connected with the cerebrospinal
nerves, but are not under the control of the will.
INFLAMMATION OF THE BRAIN AND ITS MEMBRANES (STAGGERS).
Inflammation of the brain is technically termed encephalitis and of its
membranes cerebral-meningitis, but as both conditions usually occur
together, and since it is practically impossible to distinguish one from
the other by the symptoms shown by the diseased animal, they may as well be
considered together here as varieties of the same disease. Staggers, coma,
frenzy, etc., are terms that are sometimes applied to this disease in its
different forms or stages.
_Causes._--Severe blows on the head with a hard object, or the head coming
violently in contact with the ground or other hard substance in a fall, may
be followed by encephalitis. Irritation caused by tumors in the brain may
produce inflammation. Feed containing deleterious matters--for example,
ergot (see Pl. V) and other fungi which contain a narcotic principle--is
the most frequent cause of this affection, and hence it is often called
"grass staggers" and "stomach staggers." Highly nitrogenous feeds are
blamed for causing this disease. Parasites, mineral and narcotic poisons,
hot weather, and severe exertion or excessive excitement may cause this
condition. Inflammation of the brain may occur as a complication of some
infectious disease or may follow some forms of indigestion. In many
localities certain plants have the reputation of causing staggers.
_Symptoms._--The symptoms vary much, but a careful observer will detect a
trouble connected with the nervous system without much uncertainty. The
first signs may be those of frenzy, but generally at the start the animal
is dull and sleepy, with little or no inclination to move about; the head
may be pressed against the wall or fence and the legs kept moving, as if
the animal were endeavoring to walk through the obstruction; the body,
especially the hind part, may be leaned against the side of the stall or
stable, as if for support. The bowels are constipated; the urine, when
passed, is small in quantity and darker in color than natural. There may be
trembling and even spasms of muscles in different parts. In the dull stage
the animal may breathe less frequently than is natural, and each breath may
be accompanied with a snoring-like sound. The pulse may be large and less
frequent than normal. If suddenly aroused from the drowsy state, the animal
appears startled and stares wildly. When moving about it may stagger, the
hind quarters swaying from side to side.
If delirium ensues, the cow is commonly said to be mad. She may bellow,
stamp her feet, run about wildly, grate the teeth, froth at the mouth. If
she is confined in the stable, she rears and plunges; the convulsions are
so violent in many instances that it is really dangerous for one to attempt
to render aid. The body may be covered with perspiration. She may fall; the
muscles twitch and jerk; often the head is raised and then dashed against
the ground until blood issues from the nose and mouth; the eyes may be
bloodshot and sightless; the limbs stiff and outstretched, or they may be
kicked about recklessly; the head may be drawn back and the tail drawn up;
the urine may be squirted out in spurts; often the "washer" (membrane
nictitans) is forced over the eye. When the convulsions cease they may be
followed by a period of quiet unconsciousness (coma) which is more or less
prolonged, when the animal may gradually regain consciousness, get up on
its feet, and perhaps quietly partake of food, if there be any within
reach, while at other times it arises with much difficulty and staggers
blindly about the stall or field.
It must be remembered that all the foregoing symptoms are not always seen
in the same case. In those cases usually designated "sleepy staggers" the
general symptoms of drowsiness are presented, while in other cases the
symptoms of frenzy cause the affection to be called "mad staggers." In
other cases there are symptoms of paralysis, swaying of the hind quarters,
inability to rise, etc., and sometimes these symptoms of paralysis are the
most striking manifestations and continue until death. Acute cases are
accompanied by fever.
It is well to remark that when the disease follows injuries to the head the
symptoms may not be manifested until two or three days (or longer) after
the accident.