Microscope and staining; by centrifuge; by agglutination test; by
inoculation; by tuberculin test; tuberculin; reaction; precautions,
temperature before injection, exclusive of other illness, of
parturition, abortion, heat, isolation, of hot building, of cold
draughts, of hard floor, of faulty milking, privation of water, of
change of food, of journey, of rude handling, of previous recent
tests, of antipyretics, make special examination in unthrifty, test
excluded animals later, danger of infecting through thermometer;
technique; dose; time of injecting; identification and record of
subjects; seat of injection; sterilization of syringe and skin;
temperatures hourly or every second hour from 8th to 16th or later;
typical reaction; accurate record of feeding, watering, milking or
other occasion of hyperthermia or hypothermia; passing on the value of
a rise; local swellings; chills; tremors; effect of test on general
health of reacting and nonreacting animal; action on parturient cows;
reliability of test. Relation of human to bovine bacillus; varying
character of microbes generally, of tubercle bacillus in man; bacillus
of man and bird interchangeable; tuberculosis in man and ox,
similarity, coextensive, apparent exceptions, direct infection—man to
cattle—cattle to man; encrease of tabes; experiments of Adami, Ravenel
and Garnault; experiments on cold blooded animals; bearing of
variations of susceptibility on sanitary work. Treatment: When
admissible; hygiene; rich feeding; oleaginous seeds: cod liver oil;
pneumatic cabinet; grooming; warm bath; medicated inhalations;
sulphurous acid; chlorine; formaline; calmatives; carbonate of
creosote; derivatives; streptococcic serum; air or oxygen in
peritoneum; excision of tubercle; Prevention; Extinction in cattle;
expense, supply of tuberculin and efficient veterinarians;
appraisment; indemnities; vermin; disinfection; scheduling; control of
purchases. Breeding healthy stock from infected; raising healthy
offspring without sterilizing the milk. Removal of unthrifty and
suspicious animals. Removal of animals showing objective symptoms, or,
tuberculin reaction. Generally applicable measures. Hygiene of milk,
butter, cheese, whey, oleomargarine. Hygiene of meat.
Tuberculosis may be acute or chronic, yet as seen in cattle, from casual
infection, it usually comes on very slowly and insidiously and follows a
chronic course. As the symptoms vary according to the organs involved it
will be convenient to consider these in turn beginning with such as show
the most diagnostic phenomena.
_Pulmonary Tuberculosis._ Though one of the most common and dangerous
forms of the disease this may last for months or years without any
suspicion on the part of the owner or caretaker of anything amiss. There
may be an occasional cough, short, weak, dry, wheezing, perhaps repeated
and roused by opening the stable door in cold weather, by leaving the
stable for the cold outer air, by rising suddenly in the stall, by being
driven on a run for a short distance, by drinking cold water or by
eating dusty food. If driven for some distance, or put to draught work
(ox) the subject blows more than the others. Sometimes even at rest,
breathing is slightly accelerated. Yet the spirits may be as good, the
eye as clear and full, the coat as smooth and sleek and the skin as soft
and mellow as in health. Some such animals give as much milk, of as rich
a quality, or, when put up to fatten, lay on flesh apparently as well as
their healthy fellows. In favorable cases percussion may elicit
circumscribed areas of dulness, and wincing or other sign of tenderness,
and auscultation may detect crepitation or wheezing over the same
points. By covering the nose and mouth with a sac or blanket the
breathing is rendered more labored and the morbid sounds become clearer
and more definite. The use of a stethoscope or phonendoscope may also
render them more distinct. The morbid râles are more significant of
tuberculosis if found in a number of isolated and circumscribed spots,
with healthy respiratory murmur between, than if simply surrounding a
single extended area of flatness as is usual in pneumonia. Much,
however, stands in the way of success at this early stage. The heavy
muscular and bony mass of the shoulder covers the anterior lobe and
partially muffles the auscultation sound, while it renders percussion
useless. The thick covering of the ribs in fat animals proves a serious
barrier to successful auscultation and percussion. The varying plenitude
of the abdominal viscera, and the rumbling, trickling, gurgling, and in
the case of the rumen the crepitation of the contents, tend to
complicate, obscure or cover up the pulmonary sounds. There is usually
no appreciable elevation of temperature, or a slight rise of about one
degree takes place at distant and uncertain intervals so as to render it
useless for purposes of diagnosis.
When the disease is more advanced and the pulmonary lesions more
extensive, the animals usually appear less thrifty on the same feeding,
yet fat animals are habitually killed for food that show quite extensive
pulmonary tuberculosis. With loss of condition, the coat loses its
lustre somewhat, the hair becomes dry and stares in patches, and the
skin loses its mobility and mellowness. The cough may be more frequent,
perhaps paroxysmal under excitement, harsher, more short and broken, and
either dry and husky or moist and gurgling, with a succeeding deep
inspiration perhaps a moist râle. When the skin on the last ribs is
pinched up between the fingers and thumb it is slower in flattening down
to its normal smoothness, pinching of the spine at the shoulder or back,
or it may be of the sternum, may cause wincing and even moaning, and the
same may come of percussing the ribs smartly with the closed fist. There
is now more decided evidence of flatness on percussion on the various
affected points, and of abolition or lessening of the respiratory
murmur, which is replaced by wheezing, or by bronchial blowing sound,
heart beats and abdominal crepitation or gurgling, conveyed to the ear
more clearly through the intervening consolidated tissue. The breathing
may be slightly accelerated even at rest, and becomes distinctly so on
exertion. The appetite fails somewhat and the secretion of milk lessens,
or it may become more pale and watery. Chronic tympany occurring after
meals occasionally appears, usually indicating tuberculosis of the
glands along the œsophagus with pressure on that organ impairing
eructation, and on the vagus nerve so as to impair nervous control. In
connection with this there come on signs of generalization of the
tubercle, as irregularity of the bowels, or enlargement or nodular
induration of some of the superficial lymph glands, as the pharyngeal,
prescapular, prepectoral, axillary, prefemoral, inguinal or mammary.
Expectoration is usually abundant but it is difficult to secure it for
diagnostic purposes since the moment it reaches the pharynx it is
instantly swallowed, while any that may have been projected into the
anterior nares is licked out by the pointed tongue. Nocard tried to
secure this through a cannula passed in between the tracheal rings but
with very little success. Others have introduced the hand into the
pharynx, rousing the cough by tickling the larynx, and attempting to
bring out the expectoration in the hand. When it can be secured its
solid and opaque flocculi may be stained and examined for the bacillus,
or it may be inoculated on a Guinea pig, intraperitoneally, to test its
virulence. If there are open vomicæ or complex infection the breath is
usually heavy and mawkish.
In the most advanced stages the symptoms are very characteristic. The
subject is miserably thin and wastes visibly from day to day, the hair
is dry and erect, most marked along the spine, the skin is scurfy,
rigid, lousy, and clings firmly to the bones, the eyes are pale, deeply
sunken in their sockets and bleary, the tears running over the cheeks,
while a yellowish, granular, fœtid, and often gritty discharge flows
from the nose, and dries in masses around the alæ. The cough is weak,
painful, paroxysmal, and easily roused by pinching the back or breast or
percussing the ribs. The breathing is liable to be hurried, even
panting, and the animal may stand most of its time with nose extended to
obviate the oppression that comes of recumbency. All the visible mucosæ
are pale and blanched, and the pulse weak and rapid with every
indication of anæmia. The temperature is usually raised to 104° or 105°
F. and the milk secretion is completely arrested. Indications of
generalized tuberculosis become more marked in the enlarged glands,
diarrhœa, and clouded (purulent), or blood stained urine with
microscopic casts, and even anasarca. The morbid sounds in the lungs
have become a complex variety according to the nature of the lesion,
blowing, wheezing, amphoric, friction, creaking, mucous, with the other
bruits conveyed from adjacent organs. Death usually occurs in a state of
complete marasmus, after months or years of illness.
_Tuberculosis of the Abdomen._ This usually affects the intestines,
mesenteric glands, peritoneum, liver, spleen and pancreas, and has been
known as _tabes mesenterica_. The generative organs also occasionally
suffer, in which case, an early and rather persistent symptom is
sterility, with a too frequent or it may be persistent desire for the
bull (nymphomania). There is usually a steady loss of condition in spite
of good feeding, the impaired functions of the intestinal mucosa, but
especially of the mesenteric glands, liver and pancreas, interfering
seriously with absorption and assimilation. The victims are therefore
known as piners. While there may be more or less fever, highest in the
evening, this is by no means marked, and cough and respiratory trouble
may be entirely absent. Indications are not lacking, however, of
digestive trouble. Slight tympany may follow meals, and the bowels are
irregular, costiveness alternating with diarrhœa. If heavy feeding is
resorted to, diarrhœa is the usual result, accompanied, it may be, by
colic and tympany. There is a tendency to formation of pea or nut-like
nodes under the skin of the flank, and Kleinpaul claims that the
tubercles or vegetations on the rumen can be felt by manipulation of the
left flank. Clearer evidence can often be had by rectal exploration, the
tubercles and enlarged glands being felt on the rumen, in the knotted
mesentery and in the sublumbar and subsacral region.
In case of _uterine tuberculosis_, the nymphomania may be supplemented
by a purulent discharge, and rectal exploration may detect the tubercles
on its surface, in the broad ligaments or even in the enlarged ovaries.
Great fœtor of the fæces may indicate ulceration of the mucosa,
indigestion or impaired hepatic function.
For a great length of time the disease may be virtually confined to the
mesenteric or portal glands, or even to the spleen, while the animal
enjoys fairly good health. Again, in some instances, the subject may be
fat and sleek, though the rumen, omentum or mesentery is to a large
extent literally covered with tuberculous vegetations. The
tuberculization of the intestines, mesenteric glands, liver or pancreas
interferes far more with the general health than does even extensive
peritoneal tuberculosis.
As the case advances it tends to generalization and winds up with the
general symptoms predicated above of pulmonary tuberculosis.
_Genital Tuberculosis_ in the bull is associated with nodular swelling
of the testicle, epididymus or cord, hydrocele, and exceptionally
tubercle on the penis, or in the prostatic sac.
_Mammary Tuberculosis._ This may be primary and circumscribed under
direct infection through a trauma or by the milk ducts, but more
commonly it is secondary to generalized tuberculosis. It may be a rather
firm, uniform, painless swelling of one or two quarters (usually hind
ones) without at first serious interference with milk secretion. As the
disease advances, the follicles and ducts being invaded, an irregular
knotted condition is developed, the milk becomes pale, watery,
semi-coagulated and filled with bacilli, and the climax is reached in a
densely indurated condition of the gland. From the first the mammary
lymph glands, behind and it may be in front of the organ, become
swollen, and they are finally indurated as caseation or calcification
ensues. The superficial inguinal glands often participate.
_Pharyngeal Tuberculosis._ In this rather common localisation the
retro-pharyngeal glands and those on the side of the pharynx especially
suffer, though the parotidean lymphatic gland and the submaxillary often
participate. Enlargement and induration of the tonsils and ulceration of
the mucosa may be present. There is distinct swelling of the throat or
displacement downward of the larynx, and the enlarged or hard nodular,
perhaps even shrunken, glands may often be detected by manipulation. The
nose is carried slightly protruded and a stertor or wheeze accompanies
the breathing. A glairy liquid may run from the mouth or nose, and in
this, bacilli may often be detected under the microscope. The
retro-pharyngeal glands are very subject to softening and liquefaction,
and in such a case an obscurely fluctuating swelling may be detected
above the pharynx when the hand is introduced through the mouth.
This usually terminates in generalized tuberculosis, though it will
often remain for a length of time the one appreciable localization.
_Cutaneous Tuberculosis._ The counterpart of _tuberculosis verrucosa_ of
man, this probably usually occurs by direct inoculation in a sore, yet
the infection may reach the seat of lesion through the blood. It is
usually represented by an irregular clustering warty growth, hanging
more or less loosely from the skin and showing at points caseating
centres. Bacilli may be recognized under the microscope.
_Glandular Tuberculosis._ Aside from the tuberculosis of the internal
lymph glands already referred to, tubercles may form in any group of
lymph glands, causing swelling, induration, fibroid degeneration or
tuberculous abscess. Among these may be named the glands in front of the
stifle or shoulder, at the root of the ear, beneath the zigoma, in the
jugular furrow, the prepectoral, axillary, inguinal, etc.
_Tuberculosis of the Brain and Meninges._ Disorder of the cerebral
functions occurring in generalized tuberculosis may be held to point to
this disease. The earlier meningeal symptoms are often those of
excitability, timidity, spasms, visual troubles, etc., merging later
into vertigo, hebetude, paresis, unsteady gait, local paralysis and
coma.
_Tuberculosis of the Eye._ This has been seen mostly as the result of
experimental inoculation, with conjunctival and sclerotic congestion,
corneal opacity, and the development of yellowish centres in the iris
and choroid, from which the tubercle extends into the chambers.
_Tuberculosis of the Heart, Pericardium or Pleura._ Tuberculosis of the
pleura is usually a concomitant of pulmonary phthisis, yet it may exist
for a time independently, and its diagnosis presents serious
difficulties. There may be tenderness of the intercostal spaces, a
friction sound in case of raw granular surface or vegetations, creaking
from false membranes or even flatness low down on percussion. If these
escape notice, a short painful cough and slightly hurried breathing
under exertion, in the absence of objective symptoms of lung disease,
may lead to suspicion, but the true nature of the affection must remain
in suspense. It usually leads to pulmonary or glandular (bronchial), and
finally generalized tuberculosis.
_Pericardial or Cardiac Tuberculosis_ is usually secondary and may be
suspected when friction is synchronous with the heart sounds, when the
heart beats or sounds are irregular or intermittent, or when the area of
cardiac dulness is greatly encreased.
_Tuberculosis of Bones and Joints._ This is more common in calves and
growing cattle, but may be present at any age. As affecting the vertebræ
it causes stiffness and unsteady gait, perhaps what was looked on as a
simple sprain causes persistent lameness in spite of treatment, and a
point or area of tenderness on pinching is manifest. In the large bones
and joints of the limbs, the cancellated extremities, or it may be a
simple process with its inserted tendon or ligament, shows a firm,
persistent swelling, and there is acute synovitis of the joint. In acute
cases in calves the epiphysis may become detached from the diaphysis so
as to make the limb useless. In the mature animal the enlargement and
lameness may last for years without material change. The condition may
be difficult to diagnose, in the absence of signs of tuberculosis
elsewhere in the body, or unless the synovia, withdrawn through a
sterilized nozzle, with antiseptic precautions, should show the presence
of bacilli.