his diagnosis, is aided by both subjective and objective symptoms, but the
veterinary physician, in a very large majority of cases, is obliged to rely
almost solely upon objective symptoms, and perhaps in no class of diseases
is this more true than in the exploration of those under consideration.
This condition of affairs has a strong tendency to develop observation and
discernment in the veterinarian, and not infrequently do we find that the
successful veterinary practitioner is a very accurate diagnostician. In
order to make a differential diagnosis, however, it is not only necessary
to know the structure and functions of the organs in health, but to adopt a
rigid system of details of examination, without which successful results
can not be reached.
_History._--The history of a case should always be ascertained so far as
possible. The information obtained is sometimes unsatisfactory and not to
be depended upon, but even when this is the case it is advisable to weigh
the evidence from every point of view.
In connection with the history of every case it is always of primary
importance to ascertain the cause of illness. A knowledge of the origin and
development of a disease is important, both in making a diagnosis and in
formulating the treatment. Exposure to cold and dampness is frequently the
exciting cause of affections of the organs of respiration.
The experienced practitioner is always sure to ascertain whether the
particular animal he is called on to attend is the only one in the stable
or on the premises that is similarly affected. If several animals are
similarly affected, the disease may have a common cause, which may or may
not be of an infectious nature.
Another thing that the experienced practitioner ascertains is what previous
treatment, if any, the animal has had. Medicine given in excessive doses
sometimes produces symptoms resembling those of disease.
The hygienic and sanitary conditions must always be considered in
connection with the cause as well as the treatment of disease. Much of the
disease which occurs in large dairies and elsewhere could be prevented if
owners and those in charge of animals had proper regard for the fundamental
laws of animal hygiene and modern sanitation. Disregard for these laws is
the cause of most of the diseases under consideration in this chapter.
_Attitude and general condition._--The feeling of pain in animals suffering
from serious affections of the organs of respiration is expressed to the
close observer in no uncertain language--by their flinching when the
painful part is touched; by the care with which they move or lie down; by
walking or standing to "favor" the part; by the general attitude and
expression of the eye; by the distress and suffering apparent in the face;
and by other evidences.
The general physical condition and attitude of the sick animal tell the
careful observer much that aids him in making a diagnosis and prognosis.
Cows suffering from affections of the organs of respiration usually assume
a position or attitude that is characteristic, well known to experienced
stockmen, as well as to veterinarians. When an animal has a fever or is
suffering from an inflammation, the skin is one of the first parts to
undergo a change that is apparent to the average observer, for it soon
loses its elasticity and tone, and the hair becomes dry and staring.
From the general condition or state of nutrition one is able to judge the
effect that the disease has already had upon the animal and to estimate the
strength remaining available for its restoration to health; from the degree
of emaciation one can approximate the length of time the animal has been
ill. The age and breed of the animal, as well as its constitution and
temperament, are among the things that have to be taken into account in
making a diagnosis and in overcoming the disease.
_The mucous membrane._--The mucous membrane should in all cases be
examined. It can be readily seen by everting the eyelids or by an
inspection of the lining membrane of the nostrils.
Paleness of the mucous membrane indicates weak circulation or poor blood
and may result from disease, hemorrhage, or from inappropriate feed.
In healthy animals increased redness of the mucous membrane occurs from
pain, excitement, or severe exertion, and in such instances is always
transitory. In certain pathological conditions, such as fevers and
inflammation, this condition of the mucous membrane will also be found. The
increased redness of the mucous membrane lasts during the duration of the
fever or inflammation.
A bluish or blue mucous membrane indicates that the blood is imperfectly
oxidized and contains an excess of carbon dioxid, and is seen in serious
diseases of the respiratory tract, such as pneumonia, and in heart failure.
_The secretions._--The secretions may be diminished, increased, or
perverted. In the early stage of an inflammation of a secretory organ its
secretion is diminished. In the early stage of pleurisy the serous membrane
is dry, and as the disease advances the membrane becomes unnaturally moist.
The products of secretion are sometimes greatly changed in character from
the secretion in health, becoming excessively irritant and yielding
evidence of chemical and other alterations in the character of the
secretion.
_Cough._--Cough depends upon a reflex nervous action and may be primary
when the irritation exists in the lungs or air passages, or secondary when
caused by irritation of the stomach, intestines, or other parts having
nervous communications with the respiratory apparatus. A cough is said to
be dry, moist, harsh, hollow, difficult, paroxysmal, suppressed,
sympathetic, etc., according to its character. It is a very important
symptom, often being diagnostic in diseases of the respiratory organs, but
this is a subject, however, which can be more satisfactorily treated in
connection with the special diseases of the organs in question.
_Respiration._--In making an examination of an animal observe the depth,
frequency, quickness, facility, and the nature of the respiratory
movements. They may be quick or slow, frequent or infrequent, deep or
imperfect, labored, unequal, irregular, etc., each of which indications has
its significance to the experienced veterinarian.
Sleep, rumination, pregnancy in cows, etc., modify the respiratory
movements even in health. Respiration consists of two acts--inspiration and
expiration. The function of respiration is to take in oxygen from the
atmospheric air, which is essential for the maintenance of life, and to
exhale the deleterious gas known as "carbon dioxid."
The frequency of the respiratory movements is determined by observing the
motions of the nostrils or of the flanks. The normal rate of respiration
for a healthy animal of the bovine species is from 15 to 18 times a minute.
The extent of the respiratory system renders it liable to become affected
by contiguity to many parts and its nervous connections are very important.
Rapid, irregular, or difficult breathing is known as dyspnea, and in all
such cases the animal has difficulty in obtaining as much oxygen as it
requires. Among the conditions that give rise to dyspnea may be mentioned
restricted area of active lung tissue, owing to the filling of portions of
the lungs with inflammatory exudate, as in pneumonia; painful movements of
the chest, as in rheumatism or pleurisy; fluid in the chest cavity, as in
hydrothorax; adhesions between the lungs and chest walls; compression of
the lungs or loss of elasticity; excess of carbon dioxid in the blood;
weakness of the respiratory passages; tumors of the nose and paralysis of
the throat; swellings of the throat; foreign bodies and constriction of the
air passages leading to the lungs; fevers, etc.
As already stated, it is only the careful and constant examination of
animals in health that will enable one properly to appreciate abnormal
conditions. One must become familiar with the frequency and character of
the pulse and of the respirations and know the temperature of the animal in
health, before changes in abnormal conditions can be properly appreciated.
_Temperature._--The temperature should be taken in all cases of sickness.
Experienced practitioners can approximate the patient's temperature with
remarkable accuracy, but I strongly recommend the use of the
self-registering clinical thermometer, which is a most valuable instrument
in diagnosing diseases. (See Pl. III, fig. 1.) It is advisable to get a
tested instrument, as some thermometers in the market are inaccurate and
misleading. The proper place to insert the thermometer is in the rectum,
where the instrument should be rested against the walls of the cavity for
about three minutes. The normal temperature of the bovine is 101∞ to 102∞
F., which is higher than that of the horse. A cow breathes faster, her
heart beats faster, and her internal temperature is higher than that of
the horse. Ordinary physiological influences--such as exercise, digestion,
etc.--give rise to slight variations of internal temperature; but if the
temperature rises two or three degrees above the normal some diseased
condition is indicated.
_Pulse._--The pulse in a grown animal of the bovine species in a state of
good health beats from 45 to 55 times a minute. Exercise, fright, fear,
excitement, overfeeding, pregnancy, and other conditions aside from disease
may affect the frequency and character of the pulse. It assumes various
characters according to its rapidity of beat, frequency of occurrence,
resistance to pressure, regularity, and perceptibility. Thus we have the
quick or slow, frequent or infrequent, hard or soft, full or imperceptible,
large or small pulse, the character of each of which may be determined from
its name; also that known as the intermittent, either regular or irregular.
We may have a dicrotic, or double, pulse; a thready pulse, which is
extremely small and scarcely perceptible; the venous, or jugular, pulse;
the "running down" pulse, and so on. (See p. 76.)
In cattle the pulse is conveniently felt over the submaxillary artery where
it winds around the lower jawbone, just at the lower edge of the flat
muscle on the side of the cheek. If the cow is lying down the pulse may be
taken from the metacarpal artery on the back part of the fore fetlock. The
pulsations can be felt from any superficial artery, but in order to
ascertain the peculiarities it is necessary to select an artery that may be
pressed against a bone.
[Illustration: PLATE VIII. Position of the Lung.]
There is a marked difference in the normal or physiological pulse of the
horse and that of the cow, that of the horse being full and rather tense,
while in the cow it is soft and rolling. The pulse is faster in young or
old cattle than it is in those of middle age.
_Auscultation._--Auscultation and percussion are the chief methods used to
determine the various pathological changes that occur in the respiratory
organs. Auscultation is the act of listening, and may be either mediate or
immediate. Mediate auscultation is accomplished by aid of an instrument
known as the stethoscope, one extremity of which is applied to the ear and
the other to the chest of the animal. In immediate auscultation the ear is
applied directly to the part. Immediate auscultation will answer in a large
majority of cases. Auscultation is resorted to in cardiac and certain
abdominal diseases, but it is mainly employed for determining the condition
of the lungs and air passages. Animals can not give the various phases of
respiration, as can the patients of the human practitioner. The organs
themselves are less accessible than in man, owing to the greater bulk of
tissue surrounding them and the pectoral position of the fore extremities,
all of which render it more difficult in determining pathological
conditions. (See Pl. VIII.)
The air going in and out of the lungs makes a certain soft, rustling sound,
known as the vesicular murmur, which can be heard distinctly in a healthy
state of the animal, especially upon inspiration. Exercise accelerates the
rate of respiration and intensifies this sound. The vesicular murmur is
heard only where the lung contains air and its function is active. The
vesicular murmur is weakened as inflammatory infiltration takes place and
when the lungs are compressed by fluids in the thoracic cavity, and
disappears when the lung becomes solidified in pneumonia or the chest
cavity filled with fluid as in hydrothorax. The bronchial murmur is a
harsh, blowing sound, heard in normal conditions by applying the ear over
the lower part of the trachea, and may be heard to a limited extent in the
anterior portions of the lungs after severe exercise. The bronchial murmur
when heard over other portions of the lungs generally signifies that the
lung tissue has become more or less solidified or that fluid has collected
in the chest cavity.
Other sounds, known as mucous r‚les, are heard in the lungs in pneumonia
after the solidified parts begin to break down at the end of the disease
and in bronchitis where there is an excess of secretion, as well as in
other conditions. Mucous r‚les are of a gargling or bubbling nature. They
are caused by air rushing through tubes containing secretions or pus. They
are said to be large or small as they are distinct or indistinct, depending
upon the quantity of fluid that is present and the size of the tubes in
which the sound is produced. According to their character they are divided
into dry and moist. The friction sound is produced by the rubbing together
of roughened surfaces and is characteristic of pleurisy.
_Percussion._--Percussion is that mode of examination by which we elicit
sounds by striking or tapping over the part. It may be direct or indirect.
If the middle finger of the left hand is placed firmly on the chest and
smartly tapped or struck with the ends of the first three fingers of the
right hand, the sound will be noticed to be more resonant and clear than
when the same procedure is practiced on a solid part of the body. This is
because the lungs are not solid, but are always, in health, well expanded
with air. In certain pulmonary diseases, however, as in pneumonia, they
fill up and become solid, when percussion produces a dull sound, like that
on any other solid part of the animal. When fluid has collected in the
lower part of the chest cavity the sound will also be dull on percussion.
Where there is an excess of air in the chest cavity, as in emphysema or in
pneumothorax, the percussion sound becomes abnormally loud and clear. By
practice on healthy animals the character and boundaries of the sounds can
be so well determined that any variation from them will be readily
detected, and will sometimes disclose the presence of a diseased condition
when nothing else will.
Percussion is sometimes practiced with the aid of a special percussion
hammer and an object known as a pleximeter to strike upon. A percussion
hammer is made of rubber or has a rubber tip, so that when the pleximeter,
which is placed against the side of the animal, is struck the impact will
not be accompanied with a noise. A percussion hammer and pleximeter may be
purchased from any veterinary instrument maker.
CATARRH (COLD IN THE HEAD).
Nasal catarrh is an inflammation of the mucous membranes of the nostrils
and upper air passages. Simple catarrh is not a serious disease in itself,
but if neglected is liable to be complicated with laryngitis, bronchitis,
pneumonia, plurisy, or other serious and sometimes fatal diseases of the
respiratory organs. Catarrh is a common disease among cattle. It is often
caused by sudden exposure to wet and cold after they have been accustomed
to shelter. It may arise from inhalation of irritating gases. It is also
sometimes produced by certain specific atmospheric conditions, and may
assume an enzoˆtic form. It is very debilitating, and requires prompt and
judicious treatment.
_Symptoms._--Redness of the mucous membranes of the nose and redness and
watering of the eyes are symptoms of nasal catarrh. The mucous membrane
first becomes dry; afterwards a watery discharge appears, and later, in
severe cases, the discharge becomes mucopurulent. In mild cases there is
little or no fever, but in severe ones it may run high. The animal becomes
dull, languid, and is not inclined to move about, and the appetite may
become impaired; there is also variable temperature of the horns and ears.
If in a cow giving milk the secretion diminishes, the mucus from the eyes
and nose becomes thicker and yellower. Afterwards, as the symptoms increase
in severity, the discharge becomes mucopurulent.
_Treatment._--The animal should be housed in a well-ventilated place, with
good hygienic surroundings. In cold and damp weather it should be kept warm
with blanketing, and, in severe cases, hot, medicated inhalations given. If
the fever is high, it may be reduced by giving nitrate of potassium, from 1
to 2 ounces, in the drinking water, three times daily. Diffusible
stimulants are beneficial in most cases. Too much importance can not be
attached to good nursing. There is no necessity to resort to the old system
of bleeding, purging, or the use of powerful sedatives.
EPISTAXIS (BLEEDING FROM THE NOSE).
Bleeding from the nostrils is rather rare in cattle. It may arise from any
one of a variety of causes, but usually results from disease or injury to
the mucous membranes or to violent exertions in coughing and sneezing. It
is seldom serious. It generally occurs in drops from one nostril only,
accompanied with sneezing, and without frothing. Bleeding from the lungs
comes from both nostrils, is bright red, frothy, and accompanied with a
cough.
_Treatment._--In many cases the bleeding will cease spontaneously and all
that is necessary is to keep the animal quiet and bathe the head and
nostrils with cold water. The cause of the bleeding should be learned and
governed accordingly in the treatment. In severe and exceptional cases,
when the hemorrhage is persistent and long continued, the animal's head
should be tied to a high rack or beam and cold water or ice applied, or
recourse to styptic injections taken. If the hemorrhage is profuse and
persistent, either a drench composed of 1-1/2 drams of acetate of lead
dissolved in a pint of water or 1-1/2 drams of gallic acid dissolved in a
pint of water should be given.
LARYNGITIS (SORE THROAT).
An inflammation of the mucous membrane lining the larynx is known as
laryngitis. It may be either a primary or a secondary disease, complicated
or uncomplicated. In the majority of cases it is attributable to some form
of exposure, a sudden change from warm to cold surroundings, or exposure to
cold storms. It may also result from inhaling irritating gases or from
external violence. In an acute attack of laryngitis there is an elevation
of temperature, pain on pressure over the region of the larynx, violent
paroxysms of coughing, difficult and noisy respiration. The nostrils are
dilated, the nose extended, and the animal has a frightened expression.
There is marked difficulty in swallowing.
_Treatment._--Treatment consists of fomentations and hot applications over
the throat. Stimulating liniments, mustard mixed with cold water and well
rubbed in with a stiff brush, or other forms of counterirritation may be
applied in severe cases. Hot inhalations should be frequently resorted to,
and often afford much relief to the suffering animal. In this disease
medicines should be given so far as possible in the form of electuaries
(soft solid) on account of the difficulty of deglutition. Large drafts of
medicines have a tendency to produce violent spells of coughing, and in
this way retard recovery. The subjoined formula for an electuary will be
found to answer the purpose in ordinary cases: Chlorate of potassium,
pulverized, 8 ounces; fluid extract of belladonna, 2 ounces; powdered
opium, 1 ounce; powdered licorice root, 8 ounces; sirup, sufficient
quantity; mix. Place a small tablespoonful of the mixture frequently on the
tongue or back teeth. Or the following may be used instead: Aloes, powdered
opium, and gum camphor in equal parts; mix. Rub an ounce on the molar teeth
every four or five hours. The bowels should be kept open and the diet
should be such as the patient can easily swallow. Warm, sloppy mashes,
boiled oatmeal gruel, linseed tea, and the like are the most suitable
substances. If suffocation be threatened during the course of the disease,
tracheotomy should be performed without delay. The details of the operation
are fully described under the head of "Surgical operations." (See p. 289.)
When the disease assumes a chronic form, strong counterirritation is
indicated. A cantharides blister may be applied, or the following ointment
used: Biniodid of mercury 1 part, lard 6 parts; mix. In some cases it will
be found necessary to repeat the application.
BRONCHITIS.
Bronchitis is an inflammation of the mucous membrane of the bronchial
tubes. When a primary disease, it is generally the result of what is
commonly known as "catching cold." It may be secondary to or complicated
with many of the diseases of the respiratory system. It may also be caused
by breathing irritating gases, or by the introduction of foreign bodies
into the bronchial tubes, which sometimes results from injudicious and
careless drenching when the larynx is temporarily relaxed. It may be acute
or chronic, and is divided, according to the seat of the inflammation, into
bronchitis proper when the large tubes are affected, or capillary
bronchitis when the trouble is in the smaller ones.
_Symptoms._--Loss of appetite, elevation of temperature, generally 104∞ or
105∞ F. The inspiration is incomplete, short, and painful, and the
expiration is prolonged. The pulse is increased in frequency and is hard. A
characteristic, painful cough is present, but it is paroxysmal and
incomplete. Auscultation and percussion greatly aid us in a diagnosis. A
normal sound is given on percussion. On auscultation, in the early stages,
rhonchus r‚les are detected if the larger tubes are affected, and sibilant
r‚les if the smaller ones are affected. Later mucous r‚les are noted, and
sometimes all sounds in certain parts are absent, owing to the plugging up
of the tubes. This plugging, if extensive enough, is sometimes the cause of
death, or death may result from extension of the disease to the lungs or
pleura.
_Treatment._--The animal should be placed in a light, well-ventilated box,
and the bowels kept in a soft condition by enemas, etc. Violent purgatives
should not be used. The body should be kept warm by blanketing. In the
early stages a draft composed as follows should be given three times daily:
Extract of belladonna, 2 drams; solution of acetate of ammonium, 4 fluid
ounces; water, one-half pint. In the later stage of the disease the
following formula may be substituted and given twice daily: Carbonate of
ammonium, 3 drams; liquor hydrochlorate of strychnin, 2 fluid drams;
spirits of nitrous ether, 1 fluid ounce; water, one-half pint.
In some cases the following is preferable to either of the above, and may
be given in a pint of linseed tea every four hours: Spirits of nitrous
ether, 1-1/2 ounces; aromatic spirits of ammonia, 2 ounces; powdered
camphor, 2 drams. The feed should be light and nutritious.
Bronchitis is liable to become chronic if not properly treated in the
earliest stage. In this case remedial treatment is of little value.
PLEURISY.