ANATOMY AND DISEASES OF THE CHEST; THE DIAPHRAGM; THE PERICARDIUM; THE
HEART; PLEURISY; PNEUMONIA; SPASMODIC COUGH
The chest is the superior, or in quadrupeds the anterior, cavity of the
trunk of the body: it is divided into two cavities by a membranous
partition, termed 'mediastinum;' and separated from the abdomen, or
cavity which contains the liver, spleen, pancreas, and other abdominal
viscera, by the 'diaphragm,' which is of a musculo-membranous nature.
This membrane may be described, as it is divided, into the main circular
muscle, with its central tendinous expansion forming the lower part, and
two appendices, or 'crura,' as they are termed from their peculiar
shape, constituting its superior portion. We trace the fleshy origin of
the grand muscle, laterally and inferiorly, commencing from the
cartilage of the eighth rib anteriorly, and following somewhat closely,
as we proceed backward, the union of the posterior ribs with their
cartilages, excepting, however, the two last. The attachment is
peculiarly strong. It is denticulated: it encloses the whole of the
latter and inferior part of the chest as far as the sternum, where it is
connected with the ensiform cartilage.
The diaphragm is the main agent, both in ordinary and extraordinary
respiration. In its quiescent state it presents its convex surface
towards the thorax, and its concave one towards the abdomen. The
anterior convexity abuts upon the lungs; the posterior concavity is
occupied by some of the abdominal viscera.
Thus far we have described the diaphragm as found in the horse, ox, and
sheep. There is some difference with regard to the dog. The muscular
part of the diaphragm is thick and strong in every species of dog, while
the aponeurotic expansion is comparatively smaller. From the smaller
expanse of the thorax of the dog, and the consequent little expansion of
the diaphragm, the action, although occasionally rapid and violent--for
he is an animal of speed--is not so extensive, and more muscle and less
tendon may be given to him, not only without detriment, but with evident
advantage. Therefore, although we have occasional rupture of the heart
of the dog, oftener perhaps than in the horse, there is no case of
rupture of the diaphragm on record.
The cavity of the thorax is lined by a membrane, termed pleura, which
covers the surface of the lungs.
The lungs on either side are enclosed in a separate and perfect bag,
anil each lung has a distinct pleura. The heart lies under the left
lung; and, more perfectly to cut off all injurious connexion or
communication of disease between the lungs and the heart, the heart is
enclosed in a distinct pleura or bag, termed the 'pericardium'. This
membrane closely invests the heart, supports it in its situation,
prevents too great dilatation when it is gorged with blood, and too
violent action when it is sometimes unduly stimulated. Notwithstanding
the confinement of the pericardium, the heart, when under circumstances
of unusual excitation, beats violently against the ribs, and, were it
not thus tied down, would often bruise and injure itself, and cause
inflammation in the neighbouring parts.
The 'heart' is composed of four cavities; two above, called 'auricles',
from their shape, and two below, termed 'ventricles', occupying the bulk
of the heart. In point of fact, there are two hearts--the one on the
left side propelling the blood through the frame, and the other on the
right side conveying it through the pulmonary system; but, united in the
manner in which they are, their junction contributes to their mutual
strength, and both circulations are carried on at the same time.
The beating of the heart in the dog is best examined behind the elbow on
the left side. The hand, applied flat against the ribs, will give the
number and character of the pulsations. The pericardium, or outer
investing membrane of the heart, is frequently liable to inflammation,
milked by a quickened and irregular respiration, and an action of the
heart, bounding at an early period of the disease, but becoming scarcely
recognisable as the fluid increases. The patient is then beginning
gradually to sink. A thickening of the substance of the heart is
occasionally suspected, and, on the other hand, an increased capacity of
the cavities of the heart; the parietes being considerably thinner, and
the frame of the animal emaciated.
The pulse of the greater part of our domestic animals has been
calculated by Mr. Vatel, in his excellent work on Veterinary Pathology,
to be nearly as follows:
In the horse, from 32 to 38 pulsations in a minute.
" ox or cow, " 35 " 49 "
" ass, " 48 " 54 "
" sheep, " 70 " 79 "
" goat, from 72 to 76 pulsations in a minute.
" dog, " 90 " 100 "
" cat, " 110 " 120 "
" rabbit, . . 120 "
" guinea-pig, . . 140 "
" crow, . . 136 "
" duck, . . 136 "
" hen, . . 140 "
" heron, . . 200 "
The pulse of the dog may be easily ascertained by feeling at the heart
or the inside of the knee, and it varies materially, according to the
breed, as well as the size of the animal. This is very strikingly the
case with some of the sporting dogs, with whom the force as well as the
rapidity of the pulse vary materially according to the character and
breed of the dog.
There is, occasionally, in the dog as in the human being, an alteration
of the quantity, as well as of the quality, of the blood. 'Anæmia' is
the term used to designate a deficiency in quantity; 'plethora' is the
opposite state of it. M. D'Arbor relates a very curious account of the
former:
Two dogs were sent into the hospital of the veterinary school at Lyons.
They did not appear to suffer any considerable pain. Their skin and
mucous membranes that were visible had a peculiar appearance. They had
also comparatively little power over their limbs; so little, indeed,
that they rested continually on one side, without the ability to shift
their posture. When they were placed on their feet, their limbs gave
way, and they fell the moment they were quitted. In despite of the care
that was taken of them, they died on the second day.
Incisions were made through the skin, but in opening them no blood
flowed. The venæ cavæ themselves did not contain any--there were only
two clots of blood in the cavities of their hearts. One of them, of the
size of a small nutmeg, occupied the left ventricle; the other, which
was still smaller, was found at the base of the right ventricle. The
chest of one of them enclosed a small quantity of serosity; a similar
fluid was between the dura mater and the arachnoid membrane, and the
same was the case in the larger ventricles of the encephalon. The other
viscera did not offer anything remarkable, except the paleness and
flaccidity of their tissue. The great fatigues of the chase, and the
immersion of these animals in water at the time that they were very much
heated, appeared to have been the causes of this singular disease. In
the report of the labours of the School of Alfort, in the year 1825, the
same anæmia was remarked in two dogs that died there; one of them had
lately undergone a considerable hemorrhage, and in the other anæmia had
developed itself spontaneously.
It is in fact among dogs that this extreme anæmia has been principally
observed, and is ordinarily fatal. It has been remarked by M. Crusal in
a bullock attacked with gastro-enteritis.
This disease, according to M. Vatel, is generally the symptom of a
chronic malady, or the instantaneous effect of an excessive hemorrhage.
It is rarely primary. The extreme discoloration of the tissues, and of
the mucous membrane more particularly, the disappearance of the
subcutaneous blood-vessels, and the extreme feebleness of the animal,
are the principal symptoms. There also often exists considerable
swelling of the limbs.
The following singular case of a wound penetrating into the chest and
pericardium of a dog, is recorded by Professor Delafond:
A mastiff dog fighting with another was stabbed in the chest by the
master of his antagonist. Five hours after the accident, the Professor
was sent for. On the exterior of the sternum was a laceration an inch
and a half in length, covered by a spumy fluid, from the centre of which
was heard a gurgling noise, showing that a wound had penetrated into the
sac of the pleura. The respiration was quick, and evidently painful; the
beating of the heart was also strong and precipitate. The finger being
introduced into the wound, penetrated between the fourth and fifth rib
on the left side. "Having arrived at the pleuritic sac," says the
Professor, "I gently tapped the surface of the lung, in order to assure
myself that it was not injured; my finger penetrated into the
pericardium, and the point of the heart beat against it."
He bathed the wound with a little diluted wine, and brought the edges of
it as near together as he could, and confined them with a suture,
administering a mild aperient.
On the following day, the animal walked slowly about, seeking for
something to eat; he gave him some milk. On changing the dressing, he
tried whether he could again introduce any sound into the wound; but it
would only penetrate a very little way; indeed, re-union by adhesion had
already taken place.
On the fifth day, the animal was in good spirits; the wound had a
healthy red appearance, and all tended to a speedy cure.
On the eighth day he was sent home to his master, a distance of two
leagues from his house. He saw the dog eighteen months afterwards, and
he was as eager as ever after his game.
The following is a case of rupture of the heart:--A black pointer, of
the Scotch breed, had every appearance of good health, except that she
frequently fell into a fit after having run a little way, and sometimes
even after playing in the yard. She was several times bled during and
after these fits. When I examined her, I could plainly perceive
considerable and violent spasmodic motion of the heart, and the sounds
of the beating of the heart were irregular and convulsive. She was sent
to the infirmary, in order to be cured of an attack of mange; but during
her stay in the hospital she had these fits several times: the attack
almost always followed after she had been playing with other dogs. She
appeared as if struck by lightning, and remained motionless for several
minutes, her gums losing their natural appearance and assuming a bluish
hue. After the lapse of a few minutes, she again arose as if nothing had
been the matter. She was bled twice in eight days, and several doses of
foxglove were administered to her. The fits appeared to become less
frequent; but, playing one day with another dog, she fell and expired
immediately.
The 'post mortem' examination was made two hours after death. The cavity
of the pericardium contained a red clot of blood, which enveloped the
whole of the heart; it was thicker in the parts that corresponded with
the valve of the heart; and on the left ventricle, and near the base of
the left valve of the heart, and on the external part of that viscus,
was an irregular rent two inches long. It crossed the wall of the valve
of the heart, which was very thin in this place. The size of the heart
was very small, considering the height and bulk of the dog. The walls of
the ventricles, and particularly of the left ventricle, were very thick.
The cavity of the left ventricle was very small; there was evidently a
concentric hypertrophy of these ventricles; the left valve of the heart
was of great size.
The immediate cause of the rupture of the valve of the heart had
evidently been an increase of circulation, brought on by an increase of
exercise; but the remote cause consisted in the remarkable thinness of
the walls of the valve of the heart. This case is remarkable in more
than one respect; first, because examples of rupture of the valve of the
heart are very rare; and, secondly, because this rupture had its seat in
the left valve of the heart, while, usually, in both the human being and
the quadruped, it takes place in the right; and this, without doubt,
because the walls and the valves of the right side are thinner.
Diseases of the investing membrane of the lungs, and the pleura of the
thoracic cavity, and of the substance of the lungs, are more frequent
than those of the heart.
PLEURISY,
or inflammation of the membrane of the chest and the lungs of the dog,
is not unfrequent. There are few instances of inflammation of the lungs,
or pneumonia, that do not ultimately become connected with or terminate
in pleurisy. The tenderness of the sides, the curious twitching that is
observed, the obstinate sitting up, and the presence of a short,
suppressed, painful cough, which the dog bears with strange impatience,
are the symptoms that principally distinguish it from pneumonia. The
exploration of the chest by auscultation gives a true picture of it in
pleurisy; and, by placing the dog alternately on his chest, his back, or
his side, we can readily ascertain the extent to which effusion exists
in the thoracic cavity; and, if we think proper, we can get rid of the
fluid. It is not a dangerous thing to attempt, although it is very
problematical whether much advantage would accrue from the operation.
With a favourite dog it may, however, be tried; and, to prevent all
accidents, a veterinary surgeon should be entrusted with the case.
PNEUMONIA,
or inflammation of the substance of the lungs, is a complaint of
frequent occurrence in the dog, and is singularly marked. The extended
head, the protruded tongue, the anxious, bloodshot eye, the painful
heaving of the hot breath, the obstinacy with which the animal sits up
hour after hour until his feet slip from under him, and the eye closes,
and the head droops, through extreme fatigue, yet in a moment being
roused again by the feeling of instant suffocation, are symptoms that
cannot be mistaken.
Here, from the comparative thinness of the integument and the parietes,
we have the progress of the disease brought completely under our view.
The exploration of the chest of the dog by auscultation is a beautiful
as well as wonderful thing. It at least exhibits to us the actual state
of the lungs, if it does not always enable us to arrest the impending
evil.
Mr. Blaine and myself used cordially to agree with regard to the
treatment of pneumonia, materially different from the opinions of the
majority of sportsmen. Epidemic pneumonia was generally fatal, if it was
not speedily arrested in its course. The cure was commenced by bleeding,
and that to a considerable extent, when not more than four-and-twenty or
six-and thirty hours had passed; for, after that, the progress of the
disease could seldom be arrested. Blistering the chest was sometimes
resorted to with advantage; and the cantharides ointment and the oil of
turpentine formed one of the most convenient as well as one of the most
efficacious blisters. A purgative was administered, composed of mutton
broth with Epsom salts or castor oil; to which followed the
administration of the best sedatives that we have in those cases,
namely, nitre, powdered foxglove, and antimonial powder, in the
proportion of a scruple of the first, four grains of the second, and two
grains of the third.
Congestion of the lungs is a frequent termination of pneumonia; and in
that congestion the air-cells are easily ruptured and filled with
blood. That blood assumes a black pulpy appearance, commonly indicated
by the term of 'rottenness', an indication or consequence of the
violence of the disease, and the hopelessness of the case. A different
consequence of inflammation of the lungs is the formation of tubercles,
and, after that, of suppuration and abscess, when, generally speaking,
the case is hopeless. A full account of this is given in the work on the
Horse.
Two cases of pneumonia will be useful:
Oct. 22d, 1820. A black pointer bitch that had been used lo a warm
kennel, was made to sleep on flat stones without straw. A violent cough
followed, under which she had been getting worse and worse for a
fortnight. Yesterday I saw her. The breathing was laborious. The bitch
was constantly shifting her position, and, whether she lay down or sat
up, was endeavouring to elevate her head. Her usual posture was sitting,
and she only lay down for a minute. The eyes were surrounded, and the
nose nearly stopped with mucus. V. S. [Symbol: ounce] viij. Emet.
Fever-ball twice in the day.
23d. Breathing not quite so laborious. Will not eat. Medicine as before.
Apply a blister on the chest.
24th. Nearly the same. V. S. [Symbol: ounce] vj. Bol. utheri.
26th. Decided amendment. She breathes with much less difficulty. Less
discharge both from eyes and nose. Bol. utheri.
Nov. 7th. Sent home well.
A singular and not uninstructive case came before me. A lady in the
country wrote to me to say, that her terrier was thin, dull, husking,
and perpetually trying to get something from the throat; that her coat
stared, and she frequently panted, I replied, that I apprehended she had
caught cold; and recommended bleeding to the extent of four ounces, a
grain each of calomel and emetic tartar to be given every fourth
morning, and a fever-ball, composed of digitalis, nitre, and tartrate of
antimony, on each intermediate day.
A few days after this I received another letter from her, saying, that
the dog was bled as ordered, and died on the following Thursday. That
another veterinary surgeon had been called in, who said that the first
one had punctured the 'vena cava' in the operation, and that the dog had
bled to death internally; and she wished to know my opinion. I replied,
that the charge proceeded from ignorance or malice, or both. That in one
sense he was right--the jugular, which the other had probably opened,
runs into the vena cava, and may, with some latitude, be considered a
superior branch of it; therefore, thus far the first man had punctured
the vena cava, which I had done many hundred times; but that the point
of union of the four principal veins that form the vena cava was too
securely seated in the upper part of the thorax for any lancet to reach
it. That the rupture of some small arterial vessel might have caused
this lingering death, but that the puncture of a vein would either have
been speedily fatal, or of no consequence; and that, probably, the
animal died of the disease which she had described.
SPASMODIC COUGH
is a troublesome disease to manage. Dogs, and especially those
considerably petted, are subject to frequent cough, requiring a material
difference in the treatment. Sometimes there is a husky cough, not to so
great a degree as in distemper, but followed by the same apparent effort
to get something from the throat, the same attempt to vomit, and the
ejection of mucus, frothy or adhesive, and occasionally discoloured with
bile. It proceeds from irritability or obstruction in some of the
air-passages, and oftenest of the superior ones. An emetic will clear
the fauces, or at least force out a portion of the adhesive matter which
is clogging the bronchial tubes.
A cough of this kind, and attended in its early stages by little fever,
seldom requires anything more for its cure than the exhibition of a few
gentle emetics, consisting of equal portions of calomel and emetic
tartar, given in doses varying from half a grain to one grain and a half
of each.
A harsh hollow cough is attended by more inflammatory action. The
depletive system must be adopted here. A loud and harsh cough will yield
only to the lancet and to purgatives, assisted by sedative medicines
composed of nitre, antimonial powder, and digitalis, or small doses of
syrup of poppies, or more minute doses of the hydrocyanic acid; this
last medicine, however, should be carefully watched, and only given
under surgical advice.
28th October, 1842. A spaniel was apparently well yesterday, but
towards evening a violent cough suddenly came on. It was harsh and
hollow, and terminated in retching. There was a discharge of water from
the eyes; but the nose was cool and moist. Give an emetic, and then two
grains of the James's powder.
29th The animal coughed almost the whole of the night. There was more
watery discharge from the eyes, which appeared to be red and impatient
of light; the nose continued cool, and the dog did not refuse his food.
An aperient ball was given; and twice afterwards in the day, the nitre,
antimonial powder, and digitalis.
30th. The cough is as frequent, but not very loud. Give a mixture of
syrup of poppies and prussic acid morning and night, and the ball as
yesterday.
31st. Nearly in the same state as yesterday, except that he is not so
thirsty, and does not eat so well. Give the mixture three times daily.
Nov. 1st. He had an emetic in the morning, which produced a large
quantity of phlegm, but the cough is no better. No evacuation during the
two last days. Give an aperient ball, and the mixture as before in the
evening.
The prussic acid has been fairly tried; it has not in the least
mitigated the cough, but begins to make the dog sick, and altogether to
destroy his appetite. Give three times in the day a mixture consisting
of two-thirds of a drachm of syrup of poppies, and one-third of syrup of
buckthorn. The sickness ceased, and the cough remained as before, I then
gave twice in the day half a grain of calomel, the same of opium, two
each of pulvis antimonialis and digitalis, and four grains of nitre,
morning and noon, with six grains of the Dover's powder at night. This
was continued on the 3d, 4th and 5th of November, when there were longer
intervals of rest, and the dog did not cough so harshly when the fit was
on him.
On the 6th, however, no medicine was given; but towards evening the dog
coughed as much as ever, and a decided mucous discharge commenced from
the nose and the eyes, with considerable snorting. An emetic was given,
and the balls resorted to as before.
'7th.' He appeared to be much relieved by the emetic. The cough was
better, the dog ate well, and had regained his usual spirits. The ball
as before.
'9th'. Slight tenesmus now appeared. It quickly became frequent and
violent. The dog strained very much; but the discharge was small in
quantity, and consisted of adhesive mucus. Give two drachms of castor
oil, and the fever ball with opium. The cough is worse, and the dog still
continues to strain, no blood, however, appearing.
'11th'. The opium and oil have had their desired effect, and the cough
is better.
'12th', Except the animal is kept under the influence of opium, the
cough is dreadfully troublesome. I have, however, obtained one point. I
have been permitted to subtract four ounces of blood; but blood had been
mingling with the expectorated mucus before I was permitted to have
recourse to the lancet.
'13th'. The dog is better, and we again have recourse to the fever
mixture, to which, on the '14th', I added a very small portion of the
carbonate of iron, for the dog was evidently getting weak. The sickness
has returned, and the cough is decidedly worse.
'16th'. Rub a small quantity of rheumatic embrocation, and tincture of
cantharides.
'17th.' The first application of the blister had not much effect; but
this morning it began to act. The dog ran about the house as cross as he
could be for more than an hour; there was considerable redness on the
throat and chest. The cough, however, was decidedly better.
'18th'. The cough is better. Again apply the embrocation.
'19th.' The cough and huskiness have returned. Employ an emetic, and
continue the embrocation.
'20th'. The cough is decidedly worse. Continue the embrocation, and give
the fever mixture.
'23d'. The embrocation and medicine have been daily used; but the cough
is as bad as ever. Balls of assafoetida, squills, and opium were had
recourse to.
25th. The second ball produced the most distressing sickness, but the
cough was evidently relieved. The assafoetida was discontinued.
'28th'. The cough, during the last two days, has been gradually getting
worse. It is more laborious and longer, and the intervals between it are
shorter. Give another emetic and continue the other medicine.
30th'. The effect of the emetic was temporary, and the cough is again
worse.
'Dec'. 2d'. Very little change.
5th'. The cough appears to be stationary. Again have recourse to the
antimony, digitalis, and nitre.
8th'. The cough is certainly better. Try once more the assafoetida. It
again produced sickness, but of a very mild character.
12th'. The assafoetida was again used used morning and night. The cough
continues evidently to abate.
14th'. The dog coughs very little, not more than half-a-dozen times in
the day. Notwithstanding the quantity of medicine that has been taken,
the appetite is excellent, and the spirits good.
16th'. The cough is still less frequent, but when it occurs it is
attended with retching.
19th'. The cough is daily getting better, and is not heard more than
three or four times in the four-and-twenty hours, and then very slight.
30th'. At length I can say that the cough has ceased. It is seldom that
so much trouble would have been taken with a dog. It is the neglect of
the medical attendance which is often the cause of death. Professor
Delafond, of Alfort, gives a most interesting and complete table of the
usual diagnostic symptoms of pleurisy and pneumonia.
PLEURISY.
'Commencement of the Inflammation'.
Shivering, usually accompanied by slight colicky pains, and followed by
general or partial sweating. Inspiration always short, unequal, and
interrupted; expiration full; air expired of the natural temperature.
Cough unfrequent, faint, short, and without expectoration. Artery full.
Pulse quick, small, and wiry.
'Auscultation'.
A respiratory murmur, feeble, or accompanied by a slight rubbing through
the whole extent of the chest, or in some parts only.
'Percussion'.
Slight, dead, grating sound. Distinct resonance through the whole of the
chest, and pain expressed when the sides are tapped or compressed.
'Terminations'
Delitescence. Cessation of pain; moderate temperature of the skin;
sometimes profuse general perspiration. Respiration less accelerated;
inspiration easier and deeper. Pulse fuller and softer. Breath of the
natural temperature. Return of the natural respiratory murmur and
resonance. The walls of the chest cease to exhibit increased
sensibility.
'Effusion, false Membranes'.
Inspiration more and more full.
'Auscultation and Percussion.
Complete absence of the respiratory murmur, with the crepitating
wheezing always at the bottom of the chest; sometimes a gurgling noise.
Vesicular respiration very strong in the upper region of the chest, or
in the sac opposite to the effusion.
'Continuance of the Effusion'.
Absence of the respiratory murmur gains the middle region of the chest,
following the level of the fluid. These symptoms may be found on only
one side; a circumstance of frequent occurrence in the dog, but rare in
other animals. The respiratory murmur increases in the superior region
of the chest, or on the side opposite to the effusion. Inspiration
becomes more and more prolonged. Breath always cold. Cough not existing,
or rarely, and always suppressed and interrupted. Exercise producing much
difficulty of respiration.
'Resolution or Re-absorption of the effused fluid, and Organization of
false Membrane, the consequence of Pleurisy'.
Slow but progressive reappearance of the respiratory murmur, and
disappearance of the sounds produced by the fluid. Diminution of the
force of the respiratory murmur in the superior part of the chest, or of
the lung opposite to the sac in which the effusion exists. Gradual
return of the respiratory murmur to the inferior part of the chest.
Inspiration less deep, and returning to its natural state.
'Chronic Pleurisy, with Hydrothorax'.
Inspiration short. Cough dry, sometimes with expectoration; frequent or
capricious; always absence of complete respiratory murmur in the
inferior portion of the chest. Sometimes the gurgling noise during
inspiration and expiration. Strong respiratory murmur in the superior
portion. In dogs these symptoms sometimes have existence only on one
side of the chest. The mucous membranes are infiltrated; serous
infiltration on the lower part of the chest and belly; sometimes of the
scrotum or the inferior extremities; generally of the fore legs. The
animal lies down frequently, and dies of suffocation.
PNEUMONIA.
'Commencement of the Inflammation'.
General shivering, rarely accompanied by colicky pains, followed by
partial sweats at the flanks and the inside of the thighs. Inspiration
full, expiration short. Air expired hot. Cough frequently followed by
slight discharge of red-coloured mucus. Artery full. Pulse accelerated,
strong, full, and soft.
'Auscultation'.
Absence of respiratory murmur in places where the lung is congested;
feebleness of that sound in the inflamed parts, with humid crepitating
wheezing. The respiratory murmur increased in the sound parts.
'Percussion'.
The dead grating sound confined to the inflamed parts. Distinct
resonance at the sound parts; increased sensibility of the walls of the
chest slight, or not existing at all.
'Terminations'.
Resolution. Temperature of the skin moderate. Sometimes profuse partial
sweats. Laborious respiration subsiding; inspiration less deep. Artery
less full. Pulse yielding. Breath less hot. Gradual and progressive
disappearance of the crepitating 'râle'. Slow return of the resonance.
'Red Hepatization'.
Respiration irregular and interrupted.
'Auscultation and Percussion.
Circumscribed absence of the respiratory murmur, in one point, or in
many distinct parts of the lung. The respiratory murmur increased in one
or more of the sound parts of the lung, or in the sound lung if one is
inflamed.
'Passage to a State of Gray Induration'.
The absence of respiratory murmur indicates extensive hepatization of
one lung; a circumstance, however, of rare occurrence. When the
induration is of both lungs, and equally so, the respiratory murmur and
the inspiration remain the same, except that they become irregular. The
cough dry or humid, frequent, and sometimes varying. Exercise
accompanied by difficulty of respiration, without dyspnoea.
'Resolution or Re-absorption of the Products of Inflammation of the
Parenchymatous Substance of the Lungs'.
Diminution of the force of the respiratory murmur in the sound parts.
Cessation of the crepitating wheezing. Slow return of the respiratory
murmur where it had ceased. Respiration ceases to be irregular or
interrupted, and returns slowly to its natural state, or it remains
interrupted. This indicates the passage from red to gray induration.
'Chronic Pneumonia--(Gray Induration.)'
Inspiration or expiration interrupted, cough unfrequent; suppressed;
rarely with expectoration; always interrupted. Complete absence of
respiratory murmur.
'Softening of the Induration, Ulcerations, Vomicæ, &c.'
Mucous and wheezing; mucous râle in the bronchia; discharge from the
nostrils of purulent matter, white, gray, or black, and sometimes fetid.
Paleness of the mucous membranes. The animal seldom lies down, and never
long at a time. Death by suffocation, when the matter proceeding from
the vomicæ, or abscesses, obstructs the bronchial passages, or by the
development of an acute inflammation engrafted upon the chronic one.