bony surfaces constituting a joint are displaced so as to stretch,
lacerate, or partially tear the ligaments, synovial capsule or tendons
supporting the joint, so-called sprain, or strain, or wrench results.
The articular surfaces are not sufficiently displaced to cause luxation,
but a series of periarticular injuries result, and are followed by the
symptoms which we recognise as those of strain. Joints in which movement
is restricted within narrow limits, such as the hock or fetlock, are
most liable to such injuries, which also occur in very freely movable
articulations like the shoulder and stifle.
STRAIN OF THE SHOULDER.
This accident is produced by the animal falling on its side, by slipping
at the moment of landing, the limb being extended and in contact with
the ground, by the foot slipping at the moment when it is leaving the
ground and the limb is at its extreme limit of backward extension, by
side slips, etc. The periarticular lesions will then be found on the
front, back, or internal surface of the articulation, depending on the
manner in which the accident has occurred. According to some authors,
violent muscular efforts, as well as work in soft clay soil, bogs and
rice swamps, are also capable of causing strain of the shoulder.
=Symptoms.= At first moving appears difficult, the patient lies down a
great deal, then lameness becomes characteristic. Movement of the
scapulo-humeral joint being painful, the patient endeavours as far as
possible to avoid it; the limb is advanced stiffly in an abducted
position and with a mowing movement. This semi-circular movement avoids
the necessity of flexing the scapulo-humeral angle, but diminishes the
length of the stride.
Locally, the region of the scapulo-humeral angle is swollen, doughy, and
extremely sensitive on manual examination. If the practitioner
endeavours to flex it by lifting the limb the animal flinches.
=Diagnosis.= The diagnosis is not very difficult, although the peculiar
mowing movement is also seen in other cases, such as cracked heels and
mallenders.
=Prognosis.= The prognosis is favourable, for, provided there has been
only a moderate strain of the tendons or isolated injury to the muscles,
recovery is almost certain.
=Treatment.= Treatment consists in resting the animal and in assisting
repair.
The parts can be immobilised by the application of a vesicant or mild
blister. A week or ten days later dry friction, muscular and
periarticular massage are indicated, and gentle exercise should be
commenced. The same treatment may be employed in strain of the elbow
joint and in strains of muscles or tendons in the neighbourhood of
joints. Such lesions are, however, very rare in the ox.
STRAIN OF THE KNEE.
Strain of the knee is commoner in the ox than in the horse, because of
the special conformation of the knee in the ox and the mode of working
under a yoke. This mode of working gives less individual liberty to the
fore quarters, and sometimes interferes with the animal’s efforts when
moving a load. Strains of ligaments and periarticular injuries occur as
a general rule on the inner side of the limb.
=The symptoms= consist in lameness, exaggerated sensibility on pressure,
pain on forced flexion of the knee, and swelling of the entire
periarticular region.
=The prognosis= is somewhat serious in working oxen.
=Treatment=, when applicable, should consist of stimulant dressings,
massage, and douches.
STRAIN OF THE FETLOCK.
This is one of the commonest accidents of draught oxen.
=Causation.= Working on rough, irregular, rocky ground, or on roads with
deep ruts, is the commonest cause of this condition. When the animal
moves on irregular surfaces the two claws do not bear an equal share of
weight; sometimes the whole weight is for a moment thrown on one claw.
The phalanges, therefore, are displaced inwards or outwards, or are
twisted around their vertical axis, causing the fetlock joint and its
supporting ligaments to be more or less severely strained. The internal
or external ligaments of the joint or the suspensory ligament or flexor
tendons may even be lacerated.
The fetlock may also be strained by the animal making violent efforts to
free the claws or pastern which have become fixed in a hole in the
ground, in bogging, in hobbling, or in leaping a fence.
=Symptoms.= Lameness is noticeable from the beginning, but is
unaccompanied by any visible lesion. On examination of the limb, the
entire region from the fetlock downwards is found to be sensitive to
pressure, and painful when forcibly extended or flexed from side to
side. This sensitiveness is particularly marked when the phalanges are
rotated on the shank. A few days later the entire fetlock becomes the
seat of diffused swelling.
=Diagnosis= is facilitated by the fact that the fetlock has an entirely
different appearance from that seen when tendon sheaths or the synovial
capsules of joints are distended.
=Prognosis.= The prognosis varies considerably, according to the extent
to which deep-seated structures are involved, and the gravity of the
lesions is usually proportioned to the intensity of the symptoms.
=Treatment.= Frequent cold applications, cold foot baths for an hour or
two night and morning, and even cold poultices are useful. When the pain
has somewhat diminished, which usually occurs in from three to four
days, vesicants may be employed, and, at a later stage, massage. Failing
improvement by these methods, the injured region may be fired in points.
Strain of the hind fetlock occurs under precisely similar conditions to
those above described in the case of front limbs.
STRAIN OF THE STIFLE JOINT.
Strain of the stifle joint results from over-extension of ligaments
without displacement of the patella, and also (and probably more
frequently) from injuries to the aponeurosis and tendons of insertion of
the abductor muscles of the femur and tibia.
=Causation.= Strain of the stifle may follow violent collisions, such as
occur in entering or leaving the stable, from falls on rough ground,
from direct blows, from slips, etc., or even from the sudden and violent
contraction of the muscles of the antero-external surface of the
quarter.
=Symptoms.= Lameness follows immediately or soon after the accident, and
is of a peculiar character; to avoid using the injured joint, the animal
advances the hind limb with a mowing movement.
The injured region exhibits diffuse inflammatory swelling, which impedes
palpation, and makes it difficult to determine the exact nature of the
local lesion. The thigh at the stifle is painful.
=Diagnosis and prognosis.= Diagnosis presents no considerable
difficulty. The prognosis must be based on the intensity of the
symptoms, and becomes grave if the tendons or aponeurotic insertions be
injured, or extensive damage have been done to ligaments.
=Treatment.= At first, continued cold applications, douches, and massage
are most useful; blisters are more effective in the grave cases, and
comprise not only the ordinary blisters, but the powerful mixed blister
containing tartar emetic, powdered hellebore, bichromate of potash, etc.
If for any special reason it is of importance to preserve the animal’s
life, the parts may be fired; but for economic reasons it is usually
better to fatten it for the butcher.
STRAIN OF THE HOCK JOINT.
=Causation.= Strain of the hock joint is commonest in young oxen which
are being trained to work. Their hind quarters are necessarily more or
less free, and the animals are apt to make side movements to avoid the
goad, thus exposing the hock to irregular strain.
The internal ligaments are more frequently strained than the external, a
fact due to the conformation of the hocks.
=Symptoms.= Strain is accompanied by lameness, most marked when the
animals endeavour to turn, by exaggerated sensibility of the entire hock
region, and, in grave cases, by subcutaneous œdema.
=Diagnosis and prognosis.= Diagnosis is simple. The prognosis is
sometimes grave, because a spavin or a permanent chronic enlargement of
the capsule of the true hock joint may form.
=Treatment.= It is often desirable at once to apply an extensive blister
over the whole hock and to supplement this at a later stage by cold
applications, or by continuous cold irrigation for half an hour or more
both night and morning.
In exceptional cases the use of the actual cautery becomes necessary.
III.—LUXATION OF JOINTS.
Luxation consists of permanent displacement of the bony surfaces forming
a joint, and may follow violent mechanical injury or any other cause.
Luxations have been divided into congenital, _i.e._, such as exist from
the time of birth; spontaneous, _i.e._, those which result from some
defect of conformation or constitution; and acquired or accidental,
which occur as results of falls, wounds, accidents, etc.
From the point of view of their duration, luxations are termed temporary
when they do not necessitate reduction, progressive when the tendency is
towards greater and greater displacement of the surfaces, or permanent
when reduction is impossible.
Those commonest in bovines are luxations of the femur, luxation of the
patella, femoro-tibial luxation, and luxation of the scapulo-humeral
joint.
LUXATION OF THE FEMUR.
Luxation of the head of the femur with displacement beyond the cotyloid
cavity is very frequently congenital. The condition also occurs with
some frequency in adults or aged animals in consequence of relaxation of
the articular ligaments and the absence of the subpubic ligament
(pubio-femoral ligament).
=Causation.= Luxation may be congenital, the head of the femur being
displaced backwards and carried above the cotyloid cavity. This form is
of no practical interest, because the animals are not usually reared.
More frequently in young or adult animals it assumes the spontaneous
progressive form, in consequence of degenerative changes in and
relaxation of the coxo-femoral interosseous ligament. The head of the
femur presses on the upper margin of the cotyloid cavity, which it
injures, and eventually becomes lodged in the neighbourhood of the neck
of the ilium, in the great sciatic notch.
This luxation is also found as a purely accidental occurrence in animals
which have suffered from falls and from slipping of the hind limbs
backwards or sidewards, as occasionally follows awkward leaping
movements. The slipping outwards of the limbs, which causes this form of
luxation, is comparatively easy, because of the absence of the
pubio-femoral ligament. The accident may also be followed merely by
subluxation, that is to say, tearing of the inner portion of the
capsular ligament and rupture of some portion of the adductor muscles of
the thigh without rupture of the interosseous fibres, the head of the
femur not quitting the cotyloid cavity. This accident occurs in stables
with smooth, slippery floors, and in railway trucks. It may affect one
side or both. The latter condition is exceptional.
Finally, luxation may be either complete (in which case the capsular and
interosseous ligaments are both ruptured) or incomplete. In the former
case, the head of the femur becomes displaced upwards and forwards
towards the great sciatic notch, more rarely backwards in the direction
of the ischium, and in exceptional cases downwards and inwards below the
pubis into the foramen ovale.
=Symptoms.= The symptoms vary, depending on whether the luxation is of
the spontaneous, progressive order or, on the contrary, is accidental.
In progressive luxation, the animals are able to rise and walk with
difficulty. The affected limb swings when the animal is advancing, not
as though it were paralysed, but simply as though displaced at its upper
part. Pain is exhibited when weight is placed on the limb, and there is
difficulty in movement. The limb appears shorter than its neighbour when
the animal stands on it, and the prominence representing the trochanter
is more marked. When a false joint has formed, the limb is rigid, is
moved stiffly and abducted, and the stride is shortened.
[Illustration: $1]
In accidental luxations, either of one or both limbs, the attitude
assumed by the animal is often characteristic. One of the limbs is
extended at right angles to the longitudinal axis of the body, and
sometimes both limbs assume this position, an attitude which would be
absolutely impossible under normal conditions. The animal cannot rise.
It lifts the front part of the body by rising on its knees, but the hind
quarters do not follow. The ruptured adductor muscles are unable to
bring and hold the limb parallel to the longitudinal axis of the body;
the abductors act unopposed, and at the moment when the animal makes its
greatest effort to rise the limb (or limbs) is carried outwards and the
body comes to the ground on the udder or groin.
Inspection discovers a depression where the great trochanter should be.
On applying the open hand over the hip joint, whilst an assistant who
grasps the pastern moves the limb in different directions, one can feel
and hear, in spite of the mass of muscle covering the part, a modified
crepitation due to sero-sanguinolent effusion in and around the joint.
This crepitation can also be detected by pushing the hand as high up as
possible on the internal surface of the thigh, and thus exploring the
neighbourhood of the luxation.
=Diagnosis.= The position which the animal assumes when one endeavours
to make it rise is characteristic. Diagnosis of progressive luxation,
however, is more difficult.
=Prognosis.= The prognosis is extremely grave; for, even though
reduction can be effected, one is practically unable to ensure that the
parts shall remain in position.
=Treatment.= Treatment comprises reduction of the luxation and fixation
of the parts. Reduction can be effected without very much difficulty by
casting the animal on the affected side, placing a block of wood, or a
pail, between the thighs, and manœuvring the limb in the desired
direction. As, however, subluxation is the condition most commonly seen,
there is frequently no reduction to effect. Moreover, fixation of the
joint after reduction is almost impossible in such heavy subjects, and
luxation is very liable to recur. From an economic standpoint, slaughter
is advisable or imperative.
LUXATION OF THE PATELLA.
Luxation of the patella is not uncommon in working oxen, and is
occasionally seen in cows as the result of a slip when entering or
leaving the byre, the reason being the peculiar anatomical arrangement
of the femoro-patellar articulation.
The internal lip of the trochlea of the femur is very high, the
external, on the other hand, being only slightly developed. The patella
itself is smaller than that of the horse, and possesses a small
cartilaginous prolongation, principally on its inner face, in marked
contrast with the large cartilage found in the horse. As in the latter
animal, the outward displacement of the patella is only prevented by the
internal patellar ligament and the femoro-patellar aponeurosis. Under
the influence of varying causes to which the joint is exposed, these
supporting structures often prove insufficient to prevent the patella
being displaced outwardly.
=Causation.= From an anatomical standpoint, luxation inwards seems
impossible. It certainly must be very rare and be preceded by rupture of
the external ligament. On the other hand, as in the horse, it seems
possible that the patella may be caught on the summit of the internal
lip of the trochlea, especially if the trochlea happens to present a
flattening at that point.
Outward luxation may be spontaneous or accidental. It is termed
spontaneous, when produced by relaxation of the ligaments of attachment
or by irregular muscular action; accidental, when resulting directly
from any external mechanical cause. Violent contraction of the triceps
cruralis, by lifting the patella beyond its normal limit of travel,
helps, or at least permits, the patella to be displaced outwardly at the
moment when the muscle relaxes.
Pathological relaxation of the ligaments and muscles, by allowing the
patella to descend too far on the trochlea, also renders displacement
possible, hence spontaneous luxation sometimes occurs even while the
animal is at rest in the stable. This luxation is certainly only of a
temporary character, or perhaps only of the nature of subluxation, and
is often reduced by mere muscular contraction when the animals are
forced to move.
Should the hind limb slip in a backward direction the angle of the joint
becomes more obtuse and the lips of the trochlea are turned downwards,
thus greatly favouring lateral displacement of the patella, which under
these circumstances is no longer immobilised on the trochlear pulley;
displacement outwards then occurs, constituting the condition termed
luxation.
Various forms of mechanical violence, like blows, collisions of the
stifle with the jambs of doors, falls, etc., may also bring about this
luxation.
=The symptoms= of fully-developed accidental luxation are
characteristic. Immediately the accident occurs, the limb is immobilised
in a state of complete extension; neither the stifle nor the hock joint
can be flexed, and only the fetlock joint retains any degree of
mobility.
Movement is very difficult. The hind limb appears rigid, as though
formed of one bone. The pastern is directed backwards and dragged along
the ground, and when weight is placed on the limb the anterior surface
of the pastern may almost be in touch with the ground. The limb is
advanced, but the foot cannot be placed properly on the ground.
Locally the patella is found to be outside the external lip of the
trochlea, and its internal ligaments are extremely tense.
If the luxation is spontaneous and of muscular origin, or a consequence
of relaxation of the tendons, it is usually noticeable immediately the
animal leaves the stall. The animal cannot move without great
difficulty. It grows steadily worse with the lapse of time, because the
synovial membrane becomes irritated and chronic arthritis is set up.
The symptoms are identical with those of traumatic luxation, but are
only temporary.
=Diagnosis.= The position of the limb and the displacement of the
patella are sufficiently distinctive to render diagnosis fairly easy,
and to allow of this accident being differentiated from luxation of the
femoro-tibial joint or hooking of the patella in the ischio-tibial
muscle.
=Prognosis.= The prognosis varies greatly. If the luxation is of
traumatic origin and the accompanying symptoms are not grave, reduction
may be followed by permanent recovery. On the other hand, in spontaneous
luxation recurrence is almost inevitable.
=Treatment=. The indications for treatment may be comprised in a single
phrase: reduction, with immobilisation of the parts for a sufficient
time. To effect reduction, a strip of webbing is fixed around the
pastern of the affected limb, passed over the withers, in front of the
shoulder of the opposite side, and brought round in front of the neck or
between the front limbs. By means of this an assistant exercises strong
traction on the limb until the fetlock is raised as high as the elbow of
the same side. The operator then applies strong inward pressure to the
patella, which usually slips back on to the gliding surface of the
trochlea at the first or second effort.
[Illustration: $1]
After-treatment comprises the application of a smart blister, producing
œdematous infiltration of all the tissues around the joint, and thus
impeding movement and recurrence of luxation. For this purpose various
preparations are used—_e.g._, cantharides, biniodide of mercury, croton
oil, etc. It is also advisable to fix the animal so that for a time it
cannot lie down, and to secure the pastern to the neck by means of a
side-line.
As an experiment, cases of simple fixation of the patella on the summit
of the internal lip of the trochlea might be treated by Bassi’s
method—_i.e._, subcutaneous division of the internal lateral ligament of
the patella which holds the bone in its abnormal position.
Finally, in spontaneous luxation, occurring in young animals in which
blisters have been ineffectually tried after reduction, Bénard’s bandage
may be used, though it is not generally regarded as very practical. It
consists of a piece of cloth of elongated lozenge form about four feet
in length, six inches in breadth at its centre and two inches at its
ends. Its centre is pierced by a transverse opening intended to surround
the patella, and carries a loop for the purpose of supporting the turns
of bandage. A second longitudinal opening is situated about eight inches
from the centre.
Reduction being effected, the whole region of the stifle joint is
covered with Burgundy or ordinary pitch and the bandage then applied.
The patella projects through the central opening. The end A is passed
backwards around the thigh, and through the aperture B; the two cross
ends are then brought forward, crossed again at the end, the loop over
the patella carried a second time backwards, again crossed, and finally
fixed in front under the patella. The bandage should be firmly applied,
without, however, being so tight as to interfere with circulation, and
must be left in place from eight to ten days.
[Illustration: $1]
Van Denmoegdenberg recommends placing the patient on an inclined plane,
with the hind quarters a foot higher than the front, so as to cause
permanent contraction of the anterior muscles of the quarter, and thus
immobilise the patella. Simple cold baths, frequently repeated, friction
with camphorated alcohol or essence of turpentine, complete this
original but somewhat questionable treatment, and are said to result in
recovery in a fortnight.
LUXATION OF THE FEMORO-TIBIAL ARTICULATION.
This form of luxation is rare, a fact explained by the strength of the
lateral ligaments of the joint, and of the cruciform interosseus
ligaments. It may assume different forms, according as the head of the
tibia is displaced in front of, behind, to the inside, or to the outside
of the lower extremity of the femur. In all, therefore, it may appear in
four different forms. The commonest is backward luxation.
=Causation.= With the sole exception of luxations or subluxations due to
tuberculosis (lateral luxations, either inwardly or outwardly, occurring
during tubercular arthritis, with more or less marked destruction of the
condyles), these luxations are always accidental or the result of
mechanical violence.
They result from leaping into hollows, falling into deep ditches or
ravines, or galloping through broken or steep places. Any violent shock
affecting the femur, either in front or from the outside, is capable of
causing luxation backwards or inwards.
[Illustration: $1]
=Symptoms.= The most frequent condition is backward luxation of the
upper extremity of the tibia. Movement becomes difficult, the limb is
held rigidly, and all the lower part of the leg is extended. None of the
joints can be flexed. The leg is dragged forward, without the animal
being able to place the foot flat on the ground, and the claws are
trailed over the litter or the toe grazes the soil.
On local examination the stifle is seen to be deformed. The lower
extremity of the femur and the patella appear prominent. The upper part
of the tibia is thrust backwards, and seems to have disappeared, leaving
a depression below the femoro-patellar region. The muscles forming the
back of the thigh at this level are thrust out of position, and appear
to project abnormally.
Viewed from behind, the inner line of the thigh appears more or less
convex when the upper extremity of the tibia is luxated inwardly. On
local examination the displacement of the bones can be readily detected.
In luxation forwards the prominence of the stifle is caused by the
summit of the tibial crest and by the patella, whilst the lower
extremity of the femur cannot be felt. In outward luxation the upper
extremity of the tibia forms an abnormal prominence, above which a
horizontal digital depression appears.
=Diagnosis.= Provided that the examination is made soon after the
occurrence of the accident, little difficulty will be found in coming to
a conclusion, but the diagnosis necessitates more care when examination
is deferred for two or three days, because extensive effusion then
exists. Luxations or subluxations of tuberculous origin are generally
consecutive to old-standing destructive tuberculous arthritis.
=The prognosis= is grave—firstly, because reduction is difficult; and,
secondly, because it is often impossible to maintain the reduction and
to preserve complete immobilisation of the injured joint.
=Treatment= should not be undertaken except in young animals which have
not yet attained full development.
In attempting to reduce outward or inward luxation of the tibia the
animal should be cast on the side opposite to the lesion.
Counterextension is practised by passing a length of webbing around the
limb in the region of the groin; extension in the direction of the
length of the femur by means of a loop of webbing fixed to the cannon
bone: the operator uses both hands in endeavouring to replace the head
of the tibia.
In forward luxation of the tibia counter-extension is effected by means
of a loop of webbing passed above the hock and drawn forward. Extension
is made backwards in an oblique direction, the operator again being left
free to effect reduction with both hands.
Reduction of backward luxation of the tibia is still more difficult, in
consequence of the contraction of the mass of muscle at the back of the
thigh.
Plaster bandages are the most convenient means of immobilising the parts
after reduction.
LUXATION OF THE SCAPULO-HUMERAL JOINT.
This luxation, like that of the femoro-tibial articulation, is
exceptional. It may assume one of two forms, depending on whether the
head of the humerus is displaced inwardly, or towards the back of the
glenoid cavity; but as a rule luxation occurs inwardly. Forward luxation
of the head of the humerus is almost impossible, in consequence of the
resistance offered by the tendons of the flexor brachii and antea
spinatus muscles. Similarly, luxation outwards is very difficult, the
tendon of the postea spinatus being very powerful and offering enormous
resistance.
Inwardly, on the other hand, the insertion of the subscapularis is much
less powerful, and there is no real opposition to movement of the head
of the humerus.
=Causation.= Violent mechanical shocks transverse to the upper third of
the arm may, by sheer force, displace the head of the humerus in an
inward direction, causing rupture of the internal wall of the capsular
ligament and of the subscapularis muscle. Jumping from high to low
ground and falling on the front limbs tend to displace the glenoid
cavity in front of the head of the humerus, and often result in luxation
of the bone in a backward direction, a luxation, however, which almost
always assumes a postero-internal direction. The commonest causes of
these luxations are the sideward falls of animals which have attempted
to cover others. Whether the subject be a bull or a cow, if the
stationary animal suddenly moves to one side, or if the moving animal is
frightened by the appearance of a dog, one of the front limbs may be
violently dragged away from the body; the resistance of the capsular
ligament and internal muscles of the shoulder may be overcome and
luxation produced.
=Symptoms.= Symptoms are immediately apparent: no weight can be placed
on the injured limb, and the animal moves on three legs. All muscular
action is avoided, the limb is slightly shortened as a consequence of
the head of the humerus slipping behind the shoulder, which is held
rigidly during movement; the points of the claws are dragged along the
ground.
On local examination the point of the shoulder appears to be deformed
and outwardly displaced, in consequence of the pressure exercised by the
displaced head of the humerus. Below the glenoid cavity and coracoid
process lies a depression, at the base of which the displaced humerus
can be felt. This depression, however, is soon filled up by the
sero-sanguinolent effusion consequent on luxation.
=Diagnosis.= Bearing in mind the conditions to which the accident is
due, the diagnosis presents no great difficulty.
=Prognosis.= The prognosis is grave, for although it is relatively easy
to reduce the displacement, it is very difficult to keep the joint fixed
in position.
=Treatment.= To effect reduction, the animal should be cast on the sound
side, and a loop of webbing passed under the arm, in order to provide
for counter-extension. The limb is extended by direct traction on the
cannon bone or fetlock, whilst the operator endeavours to effect
reduction with one hand placed in front and one behind the joint.
In young animals of trifling weight immobilisation may be attempted, the
best method being the application of pitch plasters. If, on the other
hand, the subject is heavy, there is so great a chance of displacement
when lying down and rising, that such cases are usually sent to the
butcher, or abandoned to chance. Relative recovery, sufficient to permit
of growth or fattening, may take place without professional assistance.
IV.—HYGROMAS.
Hygromas result from chronic inflammation of serous bursæ, naturally
existing, or of serous bursæ which form at prominent points where the
skin is exposed to repeated friction, blows, shocks, or over-extension.
They usually develop slowly, without producing marked pain or alarming
symptoms, and therefore the practitioner is seldom consulted until the
swelling has attained a considerable size.
The hygroma is usually characterised by its non-painful character and by
regular fluctuation throughout. The walls of the serous bursæ are merely
thickened, so that palpation is easy.
Should the hygroma become infected and inflamed, it assumes the same
characters as an abscess: it becomes highly sensitive, is surrounded by
œdematous infiltration, shows more marked fluctuation at some
specialised point, and eventually breaks, discharging pus.
Long-standing hygromas often have thickened fibro-cartilaginous and
extremely hard walls, which render examination more difficult.
[Illustration: $1]
Where the hygroma is much exposed to friction the skin covering it
undergoes complete transformation, the layers of epidermis becoming
converted into a substance resembling horn. The entire substance of the
wall of the hygroma then undergoes change, and is often infiltrated with
lime salts or encrusted with plates of bone of varying thickness.
HYGROMA OF THE KNEE.
This condition is very common in bovines, a fact explained by the manner
in which these animals rise. Whilst the hind limbs are being lifted, the
entire burden of the body weight is transmitted to the knees and the
tissues covering them; so that, if the ground is rough, the skin may be
sufficiently displaced to produce laceration of the subcutaneous
connective tissue, serous effusion in the layers of connective tissue,
and the immediate production of an hygroma beneath the skin and in front
of the synovial sheaths of the extensor tendons.
Hygroma is principally caused by falls on the knees, roughness of the
stable floor, prolonged decubitus during the course of a serious
disease, or after an attack of foot-and-mouth disease.
Hygromas may be no larger than a turkey’s egg or a man’s clenched fist,
but sometimes assume the dimensions of a child’s head. Calcification and
ossification of the walls and cornification of the skin are commonest in
old hygromas of the knee.
The sensibility and uniform fluctuation make mistakes in diagnosis
difficult. The condition can only be confused with distension of the
synovial sheath of the extensor metacarpi magnus; but this (synovial)
swelling extends in the same direction as the tendon, _i.e._,
vertically, attains the lower third of the radius, and is broadest
above. Hygromas must also be distinguished from tumours. Moussu only
mentions a single case of this kind, the tumour being very slightly
bosselated and, naturally, revealing no fluctuation.
=The prognosis= is not grave, though the condition may prove
troublesome, because the original injuries may be continued even during
treatment and prevent recovery.
[Illustration: $1]
=Treatment.= Success rarely follows cold applications or blistering,
which are only of value at the commencement. It is better to puncture
the cavity aseptically, remove the fluid contents, and fire the growth
in points. Free opening of the lowest portion of the swelling is
followed by discharge of liquid, but almost inevitably by infection at a
later stage, and by suppuration. Recovery certainly may occur, a slight
thickening of the anterior surface of the knee remaining; but the
process is often very prolonged. Some authors prefer to pass a seton or
drain vertically through the swelling. The results are identical with
those following free opening and drainage, suppuration being
unavoidable.
If the animal be sufficiently valuable to warrant surgical intervention,
the entire hygroma, together with its indurated wall, may be excised. An
elliptical fragment of skin is removed from the front of the swelling,
and the whole mass separated by dissecting away or tearing through the
connective tissue. Considerable care is necessary to avoid injuring the
synovial sheaths of the extensor tendons. This treatment, which is only
applicable in valuable animals, is completed by firmly suturing the lips
of the wound, and applying an antiseptic surgical dressing or a plaster
bandage similar to that used in operating on broken knees in horses.[1]
The animal must be prevented from lying down until the wound has firmly
united.
Footnote 1:
See Dollar’s “A Surgical Operating Table for the Horse.” (London: Gay
and Bird.)
HYGROMA OF THE HAUNCH.
With the exception of hygroma of the knee, hygromas are commoner on hind
than on front limbs. That of the haunch is limited to the external angle
of the ilium. It follows violent falls or collisions with door posts,
and results from laceration of the layers of subcutaneous connective
tissue and separation of the skin from subjacent parts.
The effusion is often of a sero-sanguinolent character. It is more
frequent in animals occupying narrow or irregularly shaped stalls, the
hygroma being developed through repeated collision of the angle of the
haunch with the wall. Finally, it may follow prolonged decubitus.
=Diagnosis= is easy, but the =prognosis= has a certain element of
gravity, because, should suppuration occur, it may be succeeded by
necrosis of the aponeurosis inserted into the external angle of the
ilium.
=Treatment= should first be directed to removing the cause. Of the
various modes of intervention, the best probably consists in
disinfecting the parts, puncturing the swelling, and injecting some
irritant of an antiseptic character, or simply washing out the cavity.
Iodine and carbolic solutions are most commonly employed. Firing is
contra-indicated.
HYGROMA OF THE TROCHANTER OF THE FEMUR.
This condition is rare, except in thin milch cows kept under bad
hygienic conditions and insufficiently supplied with bedding. Continual
bruising of the prominences of the quarters whilst the animal is lying
is the usual cause.
This hygroma forms a hemispherical swelling covering the trochanteric
prominence. Movement is interfered with, and the stride is shortened.
The condition can only be confused with the diffuse swellings due to
periarthritis in the coxo-femoral region, which frequently occur in cows
suffering from infectious pseudo-rheumatism.
=The prognosis= is somewhat grave, for in case of suppuration the
insertions of tendons and fascia into the summit of the trochanter may
become necrotic.
=Treatment.= The first point is to supply the animal with ample clean
bedding. The swelling may be repeatedly blistered. If considered
necessary, a puncture may be made under antiseptic precautions, the
fluid drawn off, and the cavity washed out; but it is better to avoid
opening the parts with a bistoury, on account of the danger of
suppuration and of necrosis of the tendons and aponeurotic tissues in
the neighbourhood.
HYGROMA OF THE STIFLE.
Hygroma of the stifle or of the patella appears under the skin, outside
the external ligament of the femoro-tibial articulation. It usually
follows repeated abrasion when lying down, especially if the paving of
the stalls is rough or irregular.
The swelling varies in size from a hen’s egg up to that of a child’s
head, and exhibits fluctuation throughout.
[Illustration: $1]
=The prognosis= is somewhat serious, for here again complications may
result from necrosis of neighbouring aponeuroses.
Some authors recommend passing a seton dressed with some irritant
material through the swelling. Aseptic puncture, however, seems
preferable, followed by washing out of the cavity and the application of
a blister.
HYGROMA OF THE POINT OF THE HOCK.
This hygroma usually results from blows with the ox-goad, which cause
inflammation of the subcutaneous connective tissue and œdematous
infiltration extending down the leg. Afterwards the slightest injury, or
even the friction due to the animal lying down, causes liquid to collect
and an hygroma to form.
[Illustration: $1]
This hygroma is readily infected and often suppurates; it then becomes
very sensitive, producing intense lameness. More frequently, however,
under the influence of prompt treatment, the liquid is absorbed, the
layers of subcutaneous connective tissue become hardened, and undergo
more or less extensive induration.
HYGROMA OF THE POINT OF THE STERNUM.
Hygroma of the point of the sternum is a rarity. It only occurs in thin
animals in which the point of the sternum is prominent, and which are
confined to stables with rough floors and provided with insufficient
bedding.
The swelling should not be opened, for the tissues in front of the
sternum readily become the seat of suppuration.
If treatment is desirable, the fluid may be drained off by means of an
aseptic puncture.
CHAPTER IV.
DISEASES OF MUSCLES AND TENDONS.
RUPTURE OF THE EXTERNAL ISCHIO-TIBIAL MUSCLE (BICEPS FEMORIS).
The biceps femoris muscle extends from the superior spinous process of
the sacrum to the region of the patella and the external surface of the
thigh. Above, it is inserted into the sacrum and the posterior margin of
the ischium, below into the supero-external surface of the tibia. It
completely covers the coxo-femoral articulation, and its passage over
the summit of the trochanter is lubricated by a serous bursa. The whole
of its anterior margin is connected with the fascia lata by an
aponeurotic expansion. From varying causes this aponeurotic layer may
become fissured; during the backward and forward movements of the limb
the summit of the trochanter may enter the fissure and become fixed
there by the tension and resistance of neighbouring tissues. This
accident has been described as “displacement or rupture of the biceps
femoris muscle.”
According to Cruzel, fixation of the biceps femoris may occur, in very
thin animals, without rupture of the musculo-aponeurotic layer, the
process being then simply confined to stretching of the aponeurotic
layer over the summit of the trochanter. Under such circumstances the
musculo-aponeurotic layer presents a cup-like depression, into which the
summit of the trochanter fits, and thus effectually prevents movement of
the muscle.
Whether the accident is due to an actual fissure, or only to stretching
of the aponeurosis, the symptoms are the same.
=Causes.= The principal predisposing causes are thin condition and
malformation of the limbs (turning outward of the hind toes).
The accident may occasionally be caused by a slip backwards, or by
extreme efforts in draught when ascending hills.
=Symptoms.= Immediately the accident occurs the limb becomes fixed in a
position of maximal extension. The trochanter being caught, the femur
can no longer be flexed, and the lower joints are also fixed in such a
way that the limb can only be moved as a whole. The claws are dragged
along the ground, and the affected limb, which can never be completely
advanced, is brought forward with a mowing movement.
On local examination, the trochanter appears to be very prominent, and
situated directly above a rigid cord which extends parallel with the
anterior margin of the affected muscle.
If the accident consists merely in the formation of a depression in the
muscle, in which the summit of the trochanter is fixed, and if there is
no fissuring, the muscle and the femur are certainly immobilised, but
the limb can be moved to a certain extent, the “mowing” movement is less
marked, and there is no well-defined rigid cord along the anterior
margin of the muscle.
[Illustration: $1]
=Diagnosis.= The condition can only be confused with luxation of the
patella; but manual examination of the affected parts revealing the
presence of a rigid cord below the trochanter at once removes any doubt.
=Prognosis.= The prognosis is only grave in working animals. Moreover,
the accident is now much rarer than formerly, if only because animals
are better looked after and better fed.
=Treatment.= If the accident results simply from the formation of a
depression in the musculo-aponeurotic layer which replaces the muscle at
the point where it passes over the trochanter, there is nothing to be
done. Reduction will occur spontaneously, and entire liberty of action
will be regained. Cruzel states that it is sometimes sufficient to force
the animal to move down a slope, in order to withdraw the trochanter
from the depression in which it has been lodged, and to restore its
normal mobility.
Rest and good feeding favour the deposition of fat, and soon alter the
conditions responsible for the accident; the muscles of the quarter
become surrounded with fat, the external ischio-tibial muscle (biceps
femoris) is thrust outwards on account of its superficial position, and
then cannot be ruptured by the summit of the trochanter. If, on the
other hand, the musculo-aponeurotic layer is fissured and the summit of
the trochanter firmly fixed in the opening, operation becomes necessary.
This consists in incising the anterior margin of the muscle over the
afore-mentioned rigid cord. The margins of the wound retract, the
tension of the cord is diminished, the trochanter released, and the
normal play of the limb restored.
Numerous methods of operation have been described and a number of
special instruments invented. The earlier methods consisted in simple
subcutaneous section of the rigid cord formed by the musculo-aponeurotic
layer and the muscle. Subcutaneous section is carried out exactly like
tenotomy, using straight and curved tenotomes. The seat of operation is
about three inches below the summit of the trochanter. In the absence of
tenotomes, section may be performed with a bistoury introduced from
below the muscle by means of a grooved director, which has been inserted
through a cutaneous puncture made at the point indicated over the
anterior margin of the prominent cord.
In better nourished subjects, in which this cord is less prominent, the
operator may, to ensure greater accuracy, make a vertical incision an
inch or two in length at the point selected over the anterior margin of
the muscle, isolate this muscle by means of the director, and afterwards
perform the section. Considerable hæmorrhage occasionally follows
division of some small muscular vessel, but is of no consequence unless
the wound has been infected.
RUPTURE OF THE FLEXOR METATARSI.
The rupture of this tendon-muscle is exceptional, and, according to the
description given by Furlanetto, is attended by the same symptoms as in
the horse—_i.e._, flexion of the stifle joint is not accompanied by
flexion of the hock or of the metatarsus on the tibia. The cannon bone
hangs vertically when the limb is moved.
Recovery follows prolonged rest.
Wounds and sections of tendons in the region of the cannon bone,
sections of the tendo-Achillis, etc., have been seen and described. All
such injuries may heal under antiseptic treatment and after aseptic
suture of the divided ends, provided the sutures and dressings are
applied immediately. If, on the other hand, suppuration, infection,
necrosis of tendons, synovitis or arthritis occur as complications, such
injuries become extremely serious, and from an economic standpoint
render it better to sacrifice the animal rather than attempt treatment.
Strains of tendons and tendinitis occur in the front limbs of oxen,
particularly of those used in carts. The chief indications are swelling
in the region of the cannon bone and fetlock, uneven contour of the
flexor tendons, sensibility on pressure, and lameness of varying
intensity.
=Treatment= consists in continuous cold irrigation, massage, the
application of a blister or even of the actual cautery. As a rule,
however, it is better to rest and fatten the animal.
A frequent complication of such injuries of tendons consists in
knuckling over at the fetlock.
PARASITIC DISEASES OF MUSCLES.
INFECTION WITH CYSTICERCI.
Infection of the connective and muscular tissues with cysticerci results
from the entry into the body of embryos of _Tænia solium_ and _Tænia
saginata_ of man. It occurs in man and almost all animals, but is only
of grave clinical importance in the pig and ox.
The following table shows the chief cystic (cestode) parasites of
animals, though the cysts are not always confined to muscular
structures:—
┌─────────────────────────┬───────────────────────────────────────────┐
│ Adult. │ Larva. │
├───────────────────┬─────┼───────────────────────┬───────────────────┤
│ Name. │Host.│ Name. │ Host. │
├───────────────────┼─────┼───────────────────────┼───────────────────┤
│_Tænia saginata_ │Man │_Cysticercus bovis_ │Cattle. │
│_Tænia solium_ │Man │_Cysticercus cellulosæ_│Swine and man. │
│_Tænia marginata_ │Dogs │_Cysticercus │Cattle, sheep, and │
│ │ │ tenuicollis_ │ swine. │
│_Tænia cœnurus_ │Dogs │_Cœnurus cerebralis_ │Cattle and sheep. │
│_Tænia │Dogs │_Echinococcus │Cattle, sheep, │
│ echinococcus_ │ │ polymorphus_ │ swine, man, etc. │
└───────────────────┴─────┴───────────────────────┴───────────────────┘
CYSTICERCUS DISEASE OF THE PIG.
This disease of the pig is due to _Cysticercus cellulosæ_, the cystic
form of the _Tænia solium_ or _Tænia armata_ of man. As a disease of the
pig it has been recognised from the most ancient times, and is stated to
be the cause of Moses and Mohammed having prohibited the consumption of
pork by their disciples. In the Middle Ages it formed the subject of
legislation. It was, however, only when the investigations of Van
Beneden and Kuchenmeister had completed those of the zoologists of the
seventeenth and eighteenth centuries that the evolution of tæniæ became
well known and the importance of the cystic phase clearly established.
[Illustration: $1]
[Illustration: $1]
=Causation.= The cause of cysticercus disease in the pig may be summed
up in one phrase—viz., ingestion of eggs or embryos of _Tænia solium_.
Young animals alone seem to contract the disease. After the age of eight
to ten months they appear almost entirely proof against it.
It is very rare in animals reared in confinement, but is relatively
common in those roaming at liberty; because they are much more likely to
discover human excrement and the embryos of tænia. The eggs having been
swallowed, the six-hooked embryos are set at liberty in the intestine,
perforate the tissues, enter the vessels, and are carried by the blood
into all parts of the body. Those alone develop well which reach the
interstitial and intermuscular connective tissue. The others in the
viscera usually disappear. Their presence in the depths of the muscles
produces slight general disturbance and signs of local irritation, due
to the development of the cyst itself. At the end of a month the little
vesicle is large enough to be visible to the naked eye; in forty to
forty-five days it is as large as a mustard seed, and in two months as a
grain of barley. Its commonest seats are the abdominal muscles, muscular
portions of the diaphragm, the psoas, tongue, heart, the muscles of
mastication, intercostal and cervical muscles, the adductors of the hind
legs, and the pectorals.
[Illustration: $1]
=Symptoms.= The symptoms of invasion are so little marked as usually to
pass undetected. Occasionally, when large quantities have been ingested,
signs of enteritis may occur, but these are generally ascribed to some
entirely different cause. In some cases there is difficulty in moving,
and the grunt may be altered.
Certain authors declare that the thorax is depressed between the front
limbs, but this symptom is of no particular value, and is also common to
osseous cachexia and rachitis. Paralysis of the tongue and of the lower
jaw is of greater importance. In exceptional cases, where the cysticerci
are very numerous and penetrate the brain, signs of encephalitis,
vertigo, and turning sickness (gid, sturdy) may be produced. These
signs, however, disappear, and the cysticerci undergo atrophy.
Interference with movement may give rise to suspicion when the toes of
the fore and hind limbs are dragged along the ground, and thus become
worn. This peculiarity is due to the presence of cysts in the muscles of
the limbs, but it occurs in an almost identical form in osseous
cachexia.
[Illustration: $1]
One symptom alone is pathognomonic, and it appears only at a very late
stage—viz., the presence of cysts under the thin mucous membranes which
are accessible to examination, such as those of the tongue and eye.
[Illustration: $1]
Visual examination then reveals beneath these mucous membranes the
presence of little greyish-white, semi-transparent grains the size of a
grain of barley, or even larger. Unfortunately, in an animal so
difficult to handle as the pig, this visual examination is decidedly
troublesome, and is usually replaced by palpation. In many instances the
disease does not attract attention during the patient’s life, and is
only discovered on slaughter in consequence of the lesions by which it
is characterised.
=Diagnosis.= As the characteristic lesions of cysticercus disease are to
be found in the depths of the muscular and connective tissues, and as
the external symptoms may be regarded as of doubtful significance, the
diagnosis can only be confirmed during life by manual examination of the
tongue. This examination of the tongue has been practised since the
earliest times. Aristophanes even speaks of it, and in the Middle Ages
it was performed under sworn guarantees. The regulations concerning the
inspection of meat have finally led to the suppression of this calling.
In this method of examining the tongue, the operator commences by
throwing the animal on its side, usually on the right side, and holding
it in this position by placing his left knee on its neck. He then passes
a thick stick between the jaws and behind the tusks, opens the mouth
obliquely, raising the upper jaw by manipulating the stick. Finally he
fixes one end of this last by placing his foot upon it, and holds the
other extremity by slipping it under his left arm. In this position he
is able to grasp the free end of the tongue and by digital palpation to
examine the tongue itself, the gums, the free portions of the frænum
linguæ, etc.
[Illustration: $1]
If he discovers cysts, the diagnosis is confirmed, but failure to do so
by no means disposes of the possibility of infection. Railliet declares
that about one animal in four or five shows no cysts beneath the tongue,
and, moreover, fraud is possible in this connection, it being quite
possible to prick the little cysts with a needle so that the liquid
contents escape, and examination gives no positive result. For these
reasons _intra-vitam_ examination alone is now discounted, and the chief
reliance is placed on post-mortem search.
=Prognosis.= The prognosis is very grave, not on account of danger to
the lives of the infected, but because infected meat may be offered for
human consumption. Should such meat, in an insufficiently cooked
condition, be eaten by man, its ingestion is followed by the development
of _Tænia solium_. If cooking were always perfect it would destroy the
cysticerci, but the uncertainty in this respect should prevent such meat
being consumed. The cysticerci are killed at a temperature of 125° to
130° Fahr.
[Illustration: $1]
=Lesions.= The lesions are represented by cysts alone—_i.e._, by
semi-transparent bladders, each of which contains a scolex or head armed
with four suckers and a double crown of hooks. The little bladders are
most commonly found in the muscles, lodged in the interfascicular
tissue, which they slightly irritate.
[Illustration: $1]
The number present varies extremely, depending on the intensity of
infestation and the number of eggs swallowed. Whilst in some cases
difficult to discover, in others they are so numerous that the tissues
appear strewn with them.
They are commonest in the muscles of the tongue, neck, and shoulders, in
the intercostal and psoas muscles, and in those of the quarter.
The viscera—viz., the liver, kidneys, heart, lungs, etc.—are less
commonly infested, and in these organs the cysts degenerate very
rapidly. In animals which have been infested for a long time, the cysts
may even have undergone caseo-calcareous degeneration, the liquid being
absorbed and the lesions presenting the appearance of little oblong firm
nodules.
On cutting through masses of muscle the vesicles protrude from between
the bundles.
In young animals, infestation with cysticerci causes wasting and
ill-health; subsequently the patients improve in appearance, later on
fatten, and gain marketable condition.
Of the carcases examined in Prussian slaughter-houses between 1876–82,
one in every 305 was found infested; between 1885–93, one in every 537.
=Treatment.= There is no curative treatment. Only preventive measures
are of value. These are confined to rendering it impossible for animals
to ingest eggs of the _Tænia solium_.
Cysticercus disease is rare in the north, centre, and east of France,
and in districts where animals are reared in confinement. It is commoner
where pigs are at liberty, such as Limousin, Auvergne, and Perigord. It
is frequent in North Germany, where the custom of eating half-cooked
meat contributes to the propagation of _Tænia solium_. It is also
frequent it Italy.
[Illustration: $1]
BEEF MEASLES.
=Causation.= The disease of beef measles is due to the penetration into
the connective and muscular tissues of embryos of the _Tænia saginata_,
or unarmed tænia of man.
This disease, unlike that of the pig, has only been recognised within
comparatively recent times, and only after Weisse’s experiments (St.
Petersburg, 1841) on feeding with raw flesh was attention drawn to it,
although as early as 1782 the _Tænia saginata_ had been described by
Goëze.
Measles in the ox is rarely seen in France, but is common in North and
East Africa. Alix has found it in Tunis, Dupuys and Monod in Senegal,
and it is common in the south of Algeria. The disease is due simply to
oxen swallowing eggs or embryos of the unarmed tænia, a fact which
explains the frequency of the disease in places where the inhabitants
are of nomad habits, and consequently disregard the most elementary
rules of public and general hygiene.
[Illustration: $1]
[Illustration: $1]
Furthermore, cattle in the Sahara, in Senegal and in the Indies, have a
very marked habit of eating ordure, and as no attempts are made to
prevent it, the risk to these animals is greatly increased.
As in the pig, the embryos which reach the stomach and intestine
penetrate into the circulatory system, and are thereby distributed
throughout the entire organism.
The development of the cysticercus is complete in forty days, and if
swallowed by man in infected meat after this period it again gives rise
to the _Tænia saginata_.
The age of the animals seems of less importance than in the case of the
pig, for Ostertag and Morot have seen cases of beef measles in animals
of ten years old.
=Symptoms.= The symptoms are still less marked than in the pig, and in
ordinary cases of infection always escape observation. Stiles, however,
gives the following account of a case experimentally infected:—
[Illustration: $1]
“Symptoms. Four days after feeding segments of _T. saginata_ to a
healthy three-months-old calf, the patient showed a higher temperature
(the normal temperature was 39·2° C.). The calf ate but little on that
day, showed an accelerated pulse, swollen belly, staring coat, and upon
pressure on the sides showed signs of pain. The next day the animal was
more lively, ate a little, and for nine days later did not show any
special symptoms except pain on pressure of the abdominal walls, and a
slight fever. Nine days after the infection the temperature was 40·7°
C., pulse 86, respiration 22; the calf laid down most of the time, lost
its appetite almost entirely, and groaned considerably. When driven it
showed a stiff gait and evident pain in the side. The fever increased
gradually, and with it the feebleness and low-spiritedness of the calf,
which now retained a recumbent position most of the time, being scarcely
able to rise without aid, and eating only mash with ground corn.
Diarrhœa commenced, the temperature fell gradually, and on the
twenty-third day the animal died. The temperature had fallen to 38·2° C.
During the last few days the calf was unable to rise; in fact, it could
scarcely raise its head to lick the mash placed before it. Pulse was
reduced by ten beats. On the last day the heart-beats were very much
slower, yet firm, and could be plainly felt. Several days before death
the breathing was laboured, and on the last day there was extreme
dyspnœa.”
[Illustration: $1]
=Diagnosis.= In forming a diagnosis we meet with the same difficulty as
in the case of the pig. It is always easy to examine the tongue; but
when visible lesions are absent diagnosis in the case of the ox remains
doubtful and problematical even more than in the pig.
In the carcase, diagnosis is much easier. The cysts are sought for, as
in the pig, by making sections of muscle, those usually selected being
the pterygoid, cervical, cardiac, and psoas muscles, and those of the
quarters.
=Prognosis.= The prognosis is grave, not indeed for the infected
animals, which seem little injured by the parasite, but for human
beings, who run the risk of contracting _Tænia inermis_ by eating
insufficiently-cooked meat.
A temperature of 115° to 120° Fahr. destroys the cysticerci, but in
roast meats the central temperature of the mass always remains below
this figure.
Salting for fifteen to twenty days destroys the vitality of the
parasite.
=Lesions.= The lesions are confined to the presence of the cyst and of
two little zones of chronic inflammation immediately surrounding it.
Unless heavily infested the subjects fatten just as well as others.
The vesicles are semi-transparent, ³⁄₁₆ inch to ¼ inch in length,
slightly ovoid in form, and contain a tænia head with four suckers, but
without hooks.
In seven to eight months the cysts undergo degeneration, the liquid is
absorbed, and calcium salts are deposited throughout the mass. The
lesions which remain have, in the ox, the appearance of interstitial
disseminated tuberculosis.
There is no curative treatment. The infested animal recovers
spontaneously with the lapse of time, for the cysticerci undergo
degenerative processes, but the flesh of such animals is of little
commercial value.
From a preventive standpoint we can only hope to improve matters by a
gradual and progressive change in social and public hygienic conditions.
[Illustration: $1]
When the life of the nomad shall have been entirely replaced by that of
the highly-civilised European and private hygienic precautions have
rendered it impossible for animals to obtain access to segments or eggs
of the _Tænia saginata_, beef measles will disappear.
At present, in the countries where the disease is common, one
experiences a feeling of astonishment that it is not far more frequent;
for experiment has shown that a person infected with one unarmed
tapeworm expels with the fæces an average of four hundred proglottides
per month, each proglottis or segment of the worm containing about
30,000 eggs, each of which is capable of developing into a tapeworm.
Beef measles is rather common in Germany, but rare in France,
Switzerland, and Italy.
TRICHINIASIS—TRICHINOSIS.
Trichinosis is a disease caused by the entrance into the body of the
_Trichina spiralis_. This parasite is swallowed in the larval form, and
undergoes sexual changes in the intestine, at first producing intestinal
trichinosis, which represents the first phase in the development of the
disease.
The trichinæ breed rapidly. The embryos penetrate into or are directly
deposited in the blood-vessels, which convey them to all parts of the
body, thus setting up the second phase of the disease, known as muscular
trichinosis.
[Illustration: $1]
[Illustration: $1]
Trichinosis as a disease has long been recognised. Peacock in 1828 and
J. Hilton in 1832 mentioned the existence of the cysts of trichinæ; Owen
in 1835 gave the name of _Trichina spiralis_ to the parasites contained
in the cysts. Trichinosis being common in Germany at that time, Virchow
and Leuckart undertook its investigation, but mistook other nematodes of
the intestine for the _Trichina spiralis_. In 1847 Leydy recognised that
trichinosis occurred in American pigs.
In 1860 Zenker found muscular and intestinal trichinosis on post-mortem
examination of a girl who had been suspected of suffering from typhoid
fever, and a carefully conducted inquiry revealed the fact that this
girl had some time previously eaten a quantity of raw ham. Virchow and
Leuckart returned to their investigations, and the life history of the
parasite soon became definitely known.
=Causation.= Trichinosis is capable of attacking all mammifers without
exception, from a man to a mouse; and most animals which can be made the
subjects of experiment contract the disease in varying degrees.
The intestinal form is seen in birds, but the muscles do not become
infested by the embryos.
Cold-blooded animals are proof against the disease.
[Illustration: $1]
After the ingestion of meat containing cysts of the parasite, the
processes of gastric and intestinal digestion set the larvæ at liberty.
These larvæ become sexual at the end of four to five days, and the
females, which are usually twice as numerous as the males, begin laying
eggs from the sixth day, continuing for a month to six weeks. Each
female lays approximately from 10,000 to 15,000 eggs. The embryos
perforate the intestinal walls, pass into the circulation, and are
hurried into all parts of the system. This period of infestation
constitutes the first phase of the disease.
Askanazy, in 1896, suggested that it was not the embryos which
perforated the intestinal walls and thus reached the blood-vessels, but
the fertilised female trichinæ themselves, which entered the terminal
chyle vessels and laid their eggs directly within them.
This observation is of great interest, for it contradicts the view held
by Leuckart and proves that treatment is useless even in the first
phase.
The males are about ¹⁄₁₆ inch in length, the females ⅛ inch to ⁵⁄₃₂
inch, and are ovoviviparous.
=Symptoms.= The symptoms lack precise character, even when the disease
is known to be developing, and moreover they have only been carefully
observed in experimental cases. As soon as the laying period begins,
signs of intestinal disturbance may be observed, possibly due to embryos
perforating the intestinal walls (if we accept Leuckart’s view), or,
according to Askanazy, to adult females penetrating the chyle vessels
and disturbing intestinal absorption.
These symptoms are only appreciable in cases of “massive” infestation.
If slight, the disturbance passes unperceived. In severe cases the
symptoms consist of diarrhœa, loss of appetite, grinding of the teeth,
abdominal pain in the form of dull colic, and sometimes irritation of
the peritoneum. The embryos carried by the circulation then escape into
the tissues and, like the cysticerci, become encysted, preferably in the
muscles, in the interfascicular connective tissue towards the ends of
the bundles. Each (asexual) parasite plays the part of a foreign body,
causing infiltration of serum and exudation of leucocytes in its
neighbourhood, and soon becoming encysted in the interior of a little
ovoid space surrounded by a fibro-fatty wall. Fat granules accumulate at
each end of the cyst.
[Illustration: $1]
[Illustration: $1]
[Illustration: $1]
The parasite, which at first appeared straight, soon assumes a bent
form, then that of a figure “6,” then of a figure “3,” and preserves a
latent vitality throughout the entire period of encystment. These cysts
are of very small dimensions, invisible to the naked eye, and their
discovery necessitates the use of the microscope. They are about ¹⁄₆₄th
inch in length and ¹⁄₁₂₀th inch in width. Very frequently two or three
cysts may be found arranged in line, presenting the appearance of beads
on a string: more rarely two parasites may be found in one cyst;
exceptionally, as many as six or seven. The appearance of “beads on a
string” is due to the fact that the parasites follow the interfascicular
capillaries.
In animals which are kept for a long time and fattened the cyst walls
undergo fatty infiltration. The change is commonest in pigs. In the same
way calcareous infiltration sometimes occurs, but only when the
parasites have lost their vitality. This calcareous degeneration
consists in the deposit of carbonate and phosphate of lime in the walls
of the cyst; it never begins before the seventh or eighth month after
infestation, and is sometimes much longer delayed.
No man or animal ever becomes infested except by the ingestion of meat
or drink containing larval trichinæ. The pig and small rodents are most
frequently attacked. Man contracts trichinosis by eating insufficiently
cooked infected pork. The fact that small rodents, particularly rats,
eat the bodies of their kind explains the persistence of trichinosis in
certain regions. Pigs roaming at large, and thus liable to find and eat
the dead bodies of such rodents, may contract trichinosis in this way or
from eating ordure.
For some weeks after the larvæ have penetrated the muscular tissues the
animals show stiffness of the limbs, difficulty in moving, and in
mastication, etc., but these troubles disappear in a short time.
The above facts explain why trichinosis in the pig is almost unknown in
France, Italy, and Spain. It is commoner in Germany and in certain
States of Europe, such as Holland and Russia, although investigations
had previously shown that in Paris about 7 per cent. of the sewer rats
were sufferers from trichinosis and that in Germany the percentage rose
as high as 15 to 20. In Chicago and Cincinnati, U.S.A., the proportion
of rats suffering from trichinosis has been as high as 50 to 70 per
cent., and as in some of the Northern States pigs were bred in complete
freedom, it follows that at one time very large numbers of American pigs
must have suffered from trichinosis.
In consequence of sanitary precautions this proportion has since greatly
diminished.
=Diagnosis.= During the animal’s life diagnosis is a difficult matter,
though, on the other hand, simple microscopic examination of suspected
meat is sufficient at once to settle the question. In dealing with the
living animal, however, it is necessary, as in examining suspected meat,
to obtain a fragment of muscle in order to submit it to microscopic
examination. This fragment can be obtained by the method known as
“harpoonage,”—a trocar provided with a cutting hook, or a trocar the
canula of which has a sharp-edged opening near its end, being thrust
into the muscle. On removing the trocar the elasticity of the tissues
causes a fragment to project into the opening in the canula, and on
withdrawing the latter a fragment sufficient for examination is
obtained. One may proceed in the same way by harpoonage when examining
large masses of suspected meat the surface of which reveals no lesion.
The specimen having been obtained, a few fragments of the muscular
fasciculi are crushed between two glasses and examined with a low power.
The trichinæ will be found towards the ends of the muscle near the
region of the tendons; few or none exist in the fat. These parasites are
most readily discovered in the diaphragm, in the muscles of the
shoulders and quarters, and in the psoas muscles.
=Prognosis.= The prognosis is relatively favourable so long as
infestation is only moderate. But it is very grave from the point of
view of public hygiene, on account of the possibility of persons
becoming infected by eating the diseased meat.
=Treatment.= There is no curative treatment. Formerly it was believed
that, provided the condition were early diagnosed, the intestinal form
might possibly be cured by administering purgatives and vermifuges so as
to prevent the embryos penetrating the system.
After Askanazy’s discoveries this view had to be abandoned, and the
practitioner is necessarily powerless in dealing with the muscular form.
Time alone effects improvement and a relative cure by causing
caseo-calcareous degeneration of the cysts. With a prophylactic object,
every precaution should be taken to prevent the possibility of pigs
being contaminated. This question particularly interests America,
because of the extreme prevalency of pig trichinosis there.
From the point of view of public hygiene all infected meat should be
seized and destroyed, despite the fact that perfect cooking destroys the
vitality of the parasites, which perish at 120° Fahr.
Ordinary salting but slightly affects their vitality, which explains why
from time to time the importation of meat has to be prohibited and why
meat should always be scrupulously inspected.
CHAPTER V.
RHEUMATISM.
In bovine pathology the term “Rheumatism” is applied to a number of
different morbid conditions, the sole connection between which is that
they seriously affect the organs of locomotion. This reason may perhaps
be accepted as sufficient for including the study of rheumatism amongst
diseases affecting locomotion.
The disease is of considerable importance, and for this reason the study
of rheumatism itself necessarily precedes the description of
pseudo-rheumatism, secondary rheumatism, or infectious rheumatism in
young and adult animals.
ARTICULAR RHEUMATISM.
Acute rheumatism has a clearly marked predilection for the
articulations. Sometimes the great serous membranes are simultaneously
affected (pleura, pericardium, endocardium), but only in very
exceptional circumstances are they primarily attacked. That form of
rheumatism known as visceral is as a general rule secondary in
comparison with articular rheumatism. Several joints and tendon sheaths
may be attacked at the same time. Under such circumstances rheumatism
may be defined as a febrile disease, probably of an infectious nature,
revealing itself by simple or multiple inflammation of joints and the
tissues surrounding them, and capable of becoming complicated with
inflammation of the pleura, pericardium, endocardium, meninges of the
brain, etc.
=Causation.= All authors agree in recognising the influence of heredity,
of wet and cold, of sudden changes in temperature, draughts in the
stable, prolonged exposure to low temperatures, or the chilling of
animals saturated with perspiration. These are and cannot be otherwise
than occasional causes; but the determining cause remains at present
unknown.
In human pathology it has been proved beyond dispute that a certain
relationship exists between arthritism, or the “uric acid diathesis,”
and rheumatism. This fact is so well recognised that doctors have said
that rheumatism was to arthritism what scrofula is to tuberculosis.
That, however, does not advance our knowledge of the question in the
smallest degree, and it may simply be that arthritism represents one of
the principal favouring conditions in the development of rheumatism.
In domestic animals the uric acid diathesis is little known, renal
lithiasis is no more a rarity than gravel; but at the present time no
one appears clearly to have established the relationship between these
diseases and the development of rheumatism. What, however, we must all
admit is that rheumatism exhibits all the phases of development of a
rapidly progressive infectious disease.
Numerous attempts have been made by doctors during the last few years to
discover the presence of a microscopic agent and to demonstrate its
pathological characteristics. Several microbes have been described, but
one is forced to confess that the results have until now been very
contradictory and uncertain; and yet there is little room to doubt that
the disease is of an infectious character.
=Symptoms.= The symptoms are generally well defined and well developed.
The onset is sudden; an animal which one day before appeared perfectly
well is attacked in one or several joints. Usually the upper joints of
the limb are involved—the shoulder, elbow, knee, haunch, stifle, hock.
Nevertheless, invasion is probably not as sudden as it appears to be,
and, as in the human species, the subject begins by feeling erratic
pains, which, however, pass unnoticed. The animal moves with difficulty,
as though it were suffering from laminitis, and has pain when placing
weight on the limb, while the joint attacked soon shows a swelling which
extends to the tendon sheaths and the neighbouring serous bursæ. The
local temperature is higher than that of surrounding parts, sensibility
becomes very marked, and pain attends the slightest pressure on, or even
movement of, the affected joint. Intense lameness follows, which may
even at first give rise to the suspicion of fracture. The animals remain
lying for long periods, groan from time to time, and suffer great pain
when rising.
In some cases the local manifestations appear to be transferred from one
joint to another.
These local symptoms are accompanied by high fever. The temperature
rises to 105° or 106° Fahr., the pulse to 80 or 90, and the breathing is
enormously accelerated if the patients are forced to move.
Loss of appetite is very marked. Rumination may be suspended, and these
grave symptoms are accompanied by constipation, rapid wasting, cessation
or marked diminution of the milk supply, decrease in the quantity of
urine passed, etc.
A few days after the onset, visceral complications may occur, though
fortunately such complications are far from being constant. Auscultation
and percussion sometimes reveal the lesions of pleurisy, endocarditis,
pericarditis, etc.
The development of articular rheumatism varies greatly, and may
occasionally continue for weeks or months, the condition of one joint
improving only to be followed by inflammation of another.
The visceral lesions rarely disappear completely, and it is not uncommon
to note symptoms of chronic valvular endocarditis. Relapses are somewhat
frequent, and the disease may continue in a chronic form after the acute
symptoms have disappeared.
=Lesions.= The joint itself is not alone affected. All the tissues
surrounding it are congested, swollen and painful, particularly the
sheaths and insertions of the tendons. Within the inflamed synovial
capsules of the joints an increased quantity of turbid synovia
accumulates, distending the joint and producing a condition of
hydrarthrosis.
In animals slaughtered during the course of the disease one finds
congestive infiltration of the limbs.
The temperature of the parts near the affected joints is higher than
that of neighbouring regions. Sensibility is much more acute, and the
slightest external pressure gives rise to pain.
In favourable cases the joint may appear scarcely injured. The principal
symptoms are those of pain. In old-standing cases certain permanent
changes may occur, such as thickening and hardening of the wall of the
synovial capsule, fibrous infiltration of the tissues around the joint,
or even diffuse and irregular calcareous infiltration.
Cases of false or true anchylosis are rare, the animals usually being
slaughtered before such conditions can develop.
=Complications.= The commonest complications are endocarditis
and pericarditis. Valvular endocarditis localised in the
auriculo-ventricular valves is revealed by a systolic sound, and by
tumultuous or irregular beating of the heart when the animals are forced
to move. Pericarditis, which seems rare in bovine animals, is much
commoner in sheep. This pericarditis, however, produces none of the
external signs of pericarditis due to a foreign body. Like tuberculous
pericarditis, it is only accompanied by a trifling amount of exudate,
and is recognised by increased cardiac dulness and diminution in the
cardiac sounds on auscultation.
Simple pleurisy associated with pericarditis is frequent in sheep, but
unknown or little known in the ox.
If in animals other visceral complications occur, affecting the
peritoneum, meninges of the brain or intestines, they are at present
little recognised.
=Diagnosis.= Articular rheumatism can only be confused with osseous
cachexia or laminitis. Osseous cachexia, however, possesses symptoms
peculiar to itself, and generally extends to an entire district, whilst
rheumatism appears in an isolated form. Again, the arthritis peculiar to
osseous cachexia most commonly affects the joints of the extremities
(fetlock and phalanges). The disease may be differentiated from
laminitis by simply manipulating the joints, which are painful in
rheumatism but not in laminitis, and by percussing the claws, which are
painful in laminitis but not in rheumatism, and by noting the character
of the gait.
=Prognosis.= The prognosis is grave, as in all acute diseases which are
capable of assuming a protracted chronic form. It is also necessary to
take into account the loss of condition, the possibility of relapse, and
the complications due to prolonged decubitus.
=Treatment.= The first indication is to place the patients in a nearly
constant temperature, to supply bedding generously, and to arrange for
the animal being undisturbed. Among drugs salicylate of soda gives the
best results if administered in sufficient doses—6 to 7 drams per day
for oxen or cows of medium size, 45 to 75 grains for sheep.
Diuretics, like bicarbonate of soda, nitrate of potash and hay tea or
infusion of couch grass, pellitory, etc., also give good results.
The joints attacked may be blistered, but it is often preferable to use
mild ointments, containing camphor or belladonna, because, as soon as
pain diminishes, moderate massage of the affected parts, which favours
rapid absorption of the effusions, can then at once be resorted to. The
diet should consist of easily digested food and of lukewarm hay tea,
etc. When the animals are suffering from kidney disease in any form
salicylate of soda is contra-indicated.
Antipyrin may also be of service in doses of 45 to 75 grains for bovines
and 15 grains for sheep. Preparations of methyl salicylate can only be
used for animals of value.
MUSCULAR RHEUMATISM.
Muscular rheumatism is due to causes similar to those of articular
rheumatism. The symptoms, moreover, often occur simultaneously, or may
alternate with the articular manifestations, with which they are seldom
entirely unconnected.
Moist cold seems to be the predetermining cause, whether it acts
indirectly on the nerve trunks or affects the capillary circulation in
the muscles, through the medium of the vaso-motor supply. The results
are revealed by the development of neuralgia, neuritis or interstitial
myositis; and these diseases, by producing more or less intense pain,
cause difficulty in movement or distinct lameness. Attempts have been
made to explain the development of these lesions by ascribing a certain
action to the uric acid (which is said to be in excess in the body), and
to the lactic acid, which accumulates in the muscular tissue after
fatigue or over-exertion, and may occasionally produce temporary
myositis. Up to the present time, no satisfactory proof has been
furnished enabling us to identify the myositis of rheumatism with the
myositis of over-exertion, which, moreover, appears to differ from it in
essential particulars.
=Symptoms.= Muscular rheumatism is often ill-recognised in veterinary
medicine, and closer observation would appear to suggest that it is much
less frequent than has been stated. Generalised muscular rheumatism is
rare; patients stand stiffly as though incapable of moving; the limbs
and the back appear rigid, and the animal seems only capable of changing
its position by a single movement of its whole body. One might readily
believe at first sight that the case was one of generalised laminitis or
slight generalised tetanus. The animal has difficulty in rising; when
moving the limbs are dragged, and the patient is cautious in lying down.
Most frequently the disease is localised in one region, such as the
shoulder, the loins, or the quarters. The affected part is stiff, tense,
painful, hard, and as though in a state of cramp. Palpation and pressure
reveal the presence of very exaggerated sensibility, which varies within
wide limits, according to circumstances, changes in atmospheric
conditions, etc. These local signs are accompanied by a general reaction
of varying severity, somewhat resembling that seen in articular
rheumatism. Appetite is diminished or suppressed, as is rumination; the
muzzle is dry and hot; the temperature may rise as high as 103° or 104°
Fahr.
=Lesions.= The lesions are imperfectly recognised, because those who
might most easily observe and study them have often neither the means
nor the leisure for the purpose. Possibly one would at times discover
lesions of neuritis; but in any case it is not so very rare to discover
lesions of interstitial sclerosing myositis in the depths of the muscles
of the quarter, loins, shoulders, etc., a condition rarely found in any
other disease. Naturally these are only the ultimate lesions of muscular
rheumatism; for slight attacks leave no traces visible to external
examination.
=Diagnosis.= The commonest error is that of mistaking the condition for
laminitis of all four limbs. The history often suffices to eliminate
this disease from consideration, while palpation and percussion of the
claws remove any remaining doubt.
=The prognosis= is not usually grave, and recovery sometimes follows the
adoption of good hygienic conditions. On the other hand, certain
patients lose flesh rapidly.
=Treatment.= Salicylate of soda and antipyrin still form the two most
efficacious drugs, particularly the first, which may almost be regarded
as a veritable specific in rheumatism. The doses vary with the size of
the patients, from 2½ to 7 drams per day. These doses are continued for
six to eight days consecutively. Some authors prefer salicylic acid,
which, however, is more irritant, in doses of 15 to 75 grains. Tartar
emetic, in doses of 2½ to 4 drams per day until purgation is
established, is also said to have proved of great value in the hands of
the older practitioners. Local treatment comprises stimulating frictions
with camphorated alcohol, ammonia, and oil of turpentine. Such
applications are usually of great service, particularly when associated
with methodical massage of the affected parts. These modes of treatment
should be supplemented with a proper dietary and the administration of
tepid, diuretic fluids as required.
INFECTIOUS FORMS OF RHEUMATISM OR PSEUDO-RHEUMATISM.
Under the head of infectious rheumatism or pseudo-rheumatism may be
grouped joint diseases of a rheumatic type accompanying various general
or local diseases in young animals and adults: diseases of the
umbilicus, rachitis, peripneumonia, retention of the fœtus, dysentery,
etc. These diseases are characterised by articular symptoms, which
sometimes appear early, sometimes only when the disease itself is
declining, and develop suddenly or gradually, the joint cavities
themselves either being directly invaded by the agents of the primary
disease or remaining exempt. These pseudo-rheumatic attacks are due to
the localised action of microbic toxins on the articular synovial
membranes. Sometimes the serous membranes of the large body cavities are
also implicated.
This theory explains the development of acute arthritis without the
presence of gonococci during the course of an attack of blenorrhagia in
man, and may be applied in respect of certain forms of arthritis or
synovitis without the presence of microbes in domestic animals.
INFECTIOUS RHEUMATISM IN YOUNG ANIMALS.
=Causation.= To explain the occurrence of infectious rheumatism in young
animals a variety of causes has been invoked, such as bad feeding, the
absence of that purgation which usually follows the action of the
mother’s first milk (_i.e._, colostrum), and clears the bowel of
meconium, the effect of heredity, of chills, of insufficient food, and
of unduly abundant or very rich food, which has been said to produce
indigestion and its various complications.
All these causes may play a certain part in favouring the development of
infectious rheumatism, but none constitutes the direct cause.
Lecoq and Loiset in their investigations regarding this disease in colts
mentioned the almost invariable existence of lesions in the umbilical
region. Bollinger in 1869 recognised the possibility of infection by way
of the umbilical vein. Röll and Guillebeau are of the same opinion, and
Morot’s excellent study shows that here must be sought the most frequent
point of origin of the articular symptoms. In animals born in dirty
stables the umbilical cord becomes infected at the time of birth, or its
cicatrix a few days later. The result is the development of rapidly
fatal septicæmia, suppuration in the wound, omphalitis,
omphalo-phlebitis, or umbilical arteritis; and to this infection are due
the various complications, which may appear almost immediately, as in
the case of septicæmia of calves, or may be deferred for a shorter or
longer interval, for so long indeed that the umbilicus may appear to
have healed externally (infectious pneumonia and endocarditis,
infectious arthritis, etc.). The umbilical cord and the tissues
surrounding the cicatrix form excellent culture grounds for those
microorganisms which always exist in such abundance in litter and
manure; and there is, therefore, no difficulty in understanding why in
dirty stables infection so readily occurs. The infective agents may be
of very varying kinds, a fact which explains the difference in the
symptoms which follow umbilical infection; although ovoid bacteria,
streptococcus pyogenes, and the bacilli of necrosis seem most common.
Omphalitis and omphalo-phlebitis are not the only diseases capable of
producing infectious rheumatism in young animals. Certain infections
resembling dysentery and diarrhœic enteritis are also its frequent
forerunners. In young animals even rachitis, which is accompanied by
various digestive disorders, may serve as the point of origin for
infectious rheumatism and all its complications.
In older animals—_i.e._, in animals from five to six months, or even
twelve to fifteen months—infectious rheumatism may occur without a
clearly defined cause. It then develops with the symptoms and lesions of
that condition known as “osteomyelitis of adolescence” in human
pathology. These forms of osteomyelitis are due to infection with
streptococci and staphylococci. In veterinary medicine the pathogeny has
not yet been accurately ascertained.
=Symptoms.= Infectious rheumatism in young animals assumes one of two
clinical appearances, possibly due to different causes, viz.—plastic or
suppurative arthritis following umbilical infection, and simple
exudative arthritis. In the former variety symptoms appear soon after
birth, rarely after the age of two months, and as an exception in
animals of six to eight months affected with rachitis. The onset is
sometimes sudden; the patient, though healthy on the previous evening,
is unable next morning to rise or move. Hence in France this disease has
received the titles, amongst others, of laminitis and paralysis of the
newly born.
Certain joints, often a pair, appear swollen, hot and painful. The
synovial sacs are distended, and in the upper joints of the limb appear
much more prominent than in the lower. When the patients are still able
to move they walk on three legs, but usually they remain lying
permanently, and if aroused show great difficulty in rising and very
acute pain in moving.
[Illustration: $1]
[Illustration: $1]
General disturbance is also very marked; the temperature varies between
103° and 105° Fahr. The animals are dull, have no appetite, and exhibit
intense thirst. The pulse rate and respirations are increased, and not
uncommonly symptoms of grave visceral complications, such as
endocarditis, pleurisy, pneumonia, etc., can be detected. Diarrhœic
enteritis sometimes appears as a secondary development.
The animals remain permanently lying down. They can only be induced to
rise with difficulty, and, when moved, exhibit very acute pain.
In many cases the disease then takes a rapid course and ends fatally.
Death is the usual termination whenever any of the above-mentioned
visceral complications exist. Recovery is exceptional. In certain lucky
cases, sometimes without any treatment whatever, the symptoms become
less acute, the appetite persists or improves, fever diminishes, the
condition of the joints remains stationary, and after the lapse of
several weeks there is ground for anticipating recovery. In all cases,
however, the convalescents remain thin and sickly, exhibit pain and
capricious appetite, and in very few cases indeed is there any economic
reason for keeping them alive.
More frequently infectious rheumatism terminates by abscess formation in
the joints. The articular cavity becomes filled with pus, the tissues
covering one of the synovial sacs soften, and the abscess opens,
discharging fibrinous clots, thin watery pus mixed with synovia, and
_débris_ of articular cartilages or ligaments. Pyæmia is the final
complication when the patients are not slaughtered.
In the cases comprised under the second heading the symptoms appear more
slowly and develop insidiously, the chief, viz., a tendency to remain
lying and difficulty in movement, long preceding the appearance of
exudative arthritis. The course depends chiefly on the nature of the
infective agent. In calves suffering from peripneumonia, calves from
stables in which epizootic abortion rages, rachitic calves or calves
suffering from severe diarrhœic enteritis, the joints do not become the
seat of suppuration.
In such cases the arthritis is of a simple exudative character, but
without microbic infection of the joint cavity. This form is less
dangerous, and is often curable provided the original cause be kept in
mind.
=Lesions.= The lesions are always very marked, and are quite different
from those of simple rheumatism. The synovial membranes and the
periarticular tissues are always thickened, injected, inflamed, and
infiltrated.
In more benign cases the synovial exudate from the joint cavities is
simply cloudy, contains no infectious germs, and proves sterile on
attempts at cultivation. In such cases there is no abscess formation.
But most frequently this stage of serous exudation is only temporary,
and the articular fluid, which at first seems sterile, may, when tested
some days later by means of cultures, reveal the presence of organisms.
The synovia accumulated within the joint sometimes contains fibrinous
flocculi, which are at first small, but later form veritable coagula,
filling up and thickly coating all the prominences of the joint and
moulding themselves on the extremities of the bones constituting the
articulation. Sometimes the cartilages undergo very rapid ulceration,
the subjacent layers of bone become inflamed, and the osteoarthritis
which develops is so severe and painful that the patients are forced to
remain absolutely still, and are quite incapable of rising. The lesions
may remain stationary at this point. In other cases suppuration occurs
in the articulation itself, the wall of the synovial cavity, the
periarticular tissues, and the skin soften; then the abscess breaks,
giving rise to open suppurating arthritis. Animals are rarely kept long
enough to become so gravely affected; many die before this stage, and
the others are usually slaughtered. Moreover, they rapidly perish from
exhaustion and from visceral complications of a pyæmic character.
[Illustration: $1]
In many cases post-mortem examination reveals nothing whatever in the
region of the umbilical cord (through which infection has occurred), but
the germs of infection may be found in the blood or general circulation;
or again, careful investigation may show ulceration of the umbilicus,
lesions of omphalitis, of ascending umbilical arteritis in consequence
of infection of the thrombus, of umbilical phlebitis, or of infective
peritonitis, etc. The infectious agent reaches the liver through the
blood-vessels, then attains the posterior vena cava, after which the
infection assumes the gravest possible character, producing
complications like arthritis and purulent infection, with the formation
of multiple abscesses in the depths of the viscera.
The _Staphylococcus aureus_ and various streptococci are the most
frequent but not the only causes of these infections.
=The diagnosis= is not difficult, provided the disease be not mistaken
for true rheumatism. As true rheumatism is very rare in young animals,
and as, on the other hand, attention is aroused by the presence of
lesions of the umbilicus and by the existence of diarrhœic enteritis,
rachitis, etc., there is seldom room for doubt.
=Prognosis.= The prognosis is extremely grave whenever the case results
from infection of the umbilicus. French statistics place the mortality
at 90 per cent. and German at 75 per cent.
Curative =treatment= can only be attempted with any chance of success in
the simple exudative form. Even then it is necessary to simultaneously
treat the primary disease, such as rachitis or diarrhœic enteritis.
The recommendations of former practitioners as to the use of saline
purgatives, cream of tartar, etc., were probably due to their having
recognised that diarrhœa is sometimes the primary cause.
Moussu has seen simple exudative arthritis in rachitic subjects
disappear, together with the rachitis, under proper treatment.
The indications therefore are, firstly, to take measures against the
primary disease, treating the local lesions separately with blisters,
douches, or simply cold applications and massage. Provided the general
condition can be improved, recovery may follow.
Unfortunately, this treatment is useless against infectious rheumatism
with suppurative arthritis resulting from infection of the umbilicus. In
such cases treatment, if undertaken, should be directed towards
perfectly disinfecting the umbilical wound or any existing sinuses.
Injections of strong carbolic solution, the application of antiseptic
ointments or of antiseptic pencils containing iodoform, salol, etc.,
into the sinuses, followed by a surgical dressing covering the
umbilicus, form the basis of this primary treatment, which, it need
scarcely be said, has little chance of checking the course of already
existing arthritis. The use of internal antiseptics and of antipyretics
like camphor, salicylate of soda, etc., is worthy of trial. On the other
hand, prophylactic treatment in an infected area has every chance of
succeeding. The use of dry, clean litter under the mother and the
new-born calf, thorough cleansing of the umbilical cord or umbilical
cicatrix, and the application to the umbilicus of a small surgical
dressing or even a smear of tar, almost always suffice to prevent the
occurrence of these forms of arthritis.
INFECTIOUS PSEUDO-RHEUMATISM IN ADULTS.
The infectious pseudo-rheumatism of adults differs from infectious
rheumatism in young animals in that it never becomes complicated with
suppurative arthritis, and rarely affects more than one joint at a time.
The hind limbs are the parts usually attacked, and the joints seem
predisposed to disease in the following order of frequency: the
femoro-tibial, coxo-femoral, and hock joints.
On account of its greater frequency in cows, it has been termed
“arthritis of milch cows” and “infectious arthritis of milch cows,” etc.
In reality it may also attack bulls and oxen, but such cases are
exceptional.
=Causation.= First mentioned by Coulbeaux in 1824, and by Pauleau in
1832, this disease has been well studied by Ph. Heu. Old works mention
it as attacking good milkers in the best dairies around Paris, and Heu
declares it to be the most deadly disease after peripneumonia and
tuberculosis.
This form of arthritis usually appears in an insidious form after
abortion, retention of the fœtus, or post-partum metritis. In cases of
epizootic abortion infectious rheumatism sometimes assumes an epizootic
form, and completes the devastation begun by abortion. Under other and
much rarer circumstances it may follow enteritis of adults or attacks of
mammitis, etc. The pathogeny of these forms of arthritis is not
difficult to understand, for in the greater number of instances they
form delayed consequences of local uterine infection.
[Illustration: $1]
The soluble products secreted by infectious organisms multiplying within
the uterus are absorbed by the uterine mucous membrane, causing slow
intoxication; and in consequence of the special elective affinity which
the toxins show for the articular serous membranes, and in many cases
also for the visceral serous membranes, the special characteristics are
developed. Under certain circumstances the joint cavity may even become
the seat of true microbic infection.
=Symptoms.= The appearance of the first symptoms is difficult to
identify, for many cows abort, fail to “cleanse,” or become affected
with metritis without infectious rheumatism supervening. It is a
long-delayed condition, which may be postponed for weeks or even for
several months after an abnormal parturition, and to a time when the
symptoms of metritis have almost entirely disappeared. The onset is
characterised by difficulty in rising, and soon afterwards by lameness,
or by the animal failing to place weight on one of the hind limbs. The
affected joint, usually one of the articulations of the stifle, appears
markedly enlarged, is not appreciably hot to the touch, but reveals a
certain amount of painful sensibility on pressure. The periarticular
tissues are infiltrated and the synovial sacs slightly distended.
[Illustration: $1]
[Illustration: $1]
After a few days, a week or two at most, the periarticular swelling
diminishes, and the condition appears to remain stationary.
Appetite is normal or only diminished. The pain continues, and causes
progressive wasting and diminution in the yield of milk.
If at this time the practitioner makes a careful digital examination of
the diseased region, he may find one of two conditions. In the first,
the synovial sacs appear distended, fluctuating and in exactly the same
condition as in ordinary bog spavin. This is what has been termed the
exudative form of infectious arthritis. In the second, the enlarged
joint remains very sensitive, the walls of the synovial sac are
thickened, fluctuation is either absent or only slightly marked, but
induration is very manifest. This constitutes the plastic form.
[Illustration: $1]
Exudative arthritis is the form usually seen at first. It may preserve
its primary characteristics, but only too often proves to be the
forerunner of the plastic form, which develops with the lapse of time.
If nothing is done wasting becomes more marked, and is accompanied by
cachexia. The animals are unable to rise, the complications inseparable
from decubitus occur, and wasting or secondary purulent infection sets
in.
=Lesions.= In the exudative form the changes are confined to
inflammation and thickening of the synovial membranes, intra-articular
exudation, and sometimes grooving of the cartilages without ulceration
of the articular surfaces and without disorganisation of the joint.
The plastic form, on the other hand, leads to destruction of the
cartilages, ligaments, and sub-cartilaginous bony layers, induration and
calcification of the walls of the synovial cavity, and even periostitis
of the ends of the bones, with the formation of false joints. The
internal surface of the inflamed synovial membranes begins to granulate,
the fibrous clots distending the articular dilatations are perforated by
these extending granulations, and fibrous tracts soon develop even in
the articulation itself, undergo calcification, and produce complete
anchylosis.
=Diagnosis.= The diagnosis is easy. The animal’s history and symptoms,
and the stationary character of the pain in the earlier stages are
sufficient to prevent any error.
=Prognosis.= The prognosis is grave, but not fatal. In the exudative
form recovery may follow early treatment. In the plastic form, however,
the chances of success are extremely meagre.
=Treatment.= It is easier to prevent than cure, particularly in these
forms of arthritis. The means are simple, and consist in always treating
the post-partum infection as soon as it is recognised. The animals can
be effectively safeguarded against later articular complications by the
free use of intra-uterine antiseptic injections, until the uterine
injuries have wholly healed, and by the administration of saline
purgatives and diuretics.
When infectious arthritis is diagnosed, it is still necessary to resort
to the same methods if the uterine symptoms persist, and to complete the
treatment by local applications.
The best method of local treatment seems to consist in puncturing the
articulation aseptically, removing almost all of the liquid exudate, and
immediately thereafter firing the skin covering the joint in points or
lines.
If treatment has been invoked too late, if plastic arthritis with the
formation of fibrous bands within the joint and destruction of the
cartilages and calcification of ligaments, etc., already exists, there
is no economic object in undertaking treatment. Fattening may be
attempted, or the animals may be handed over to the butcher, if wasting
is not too far advanced.
The use of cold douches, plaster bandages, blisters containing nitrate
of mercury, painting with sulphuric acid, etc., are too inconvenient and
too inefficient to be recommended in actual practice. Similarly, the
salicylate of soda, which is so useful in simple rheumatism, has no real
superiority over diuretics in this condition.
SCURVY-SCORBUTUS.
=Definition.= “Scurvy is a subacute or chronic trophic disorder
characterised by debility, inanition, anæmia, swelling and bleeding of
the gums, gingival ulceration, dropping of the teeth, and petechial or
more extensive hæmorrhages and exudations in the skin, serosa, and solid
tissues.”
=Causes.= “Among the lower animals, pigs especially suffer, when kept in
close, foul quarters and fed on a monotonous and insufficient ration.
Formerly scurvy ... was attributed to an exclusive diet of salt food; to
excess of sodium and deficiency of potassium salts; to the absence of
fresh vegetables; to tainted food, etc. In pigs the food and environment
are usually chiefly at fault, the subjects have been kept ... in foul
buildings, in a hot, moist atmosphere, and with an uniform diet of maize
or other unvarying and insufficient ration. Röll attaches great
importance to putrid food. Benion has found the affection mainly in
obese swine, the forced feeding and intestinal fermentations manifestly
operating as factors. Hess and others attribute the disease in pigs to
the germ of erysipelas. Stengel has produced purpuric disease in animals
by inoculation of the extravasated blood from human scurvy patients.
Muller and Babès found a slender bacillus and streptococci in the
tissues of scorbutic gums.... There is considerable presumption of the
existence of a microbian cause, the efficiency of which is dependent on
the unhygienic conditions above stated, while these unwholesome
conditions are equally non-pathogenic in the absence of the microbe.”
=Lesions.= “The blood is black and incoagulable or clots loosely, rigor
mortis is slight, changes may be found in the number and character of
the white and red blood globules, but are not constant; there is usually
an excess of sodium salts and deficiency of potassium ones, and there is
marked petechiation of the skin, mucosæ and serosæ. The bone marrow may
be abnormally red and the bones fractured at the epiphyses, or
carious.... The gums are softened, swollen, red and uneven, with
hæmorrhagic discoloration, erosions, necrotic areas and ulcers.”
=Symptoms.= “Anorexia or fastidious appetite, prostration, debility and
sluggish, indifferent movements, are followed by the local lesions on
the skin and gums. On the skin appear petechiæ and extravasations, which
often implicate the bristles, so that they may be shed or pulled out
with ease, the bulbs appearing dark and blood-stained (bristle rot).
These may be followed by necrotic sloughs, and deep ulcers that are slow
to heal. The gums are red and swollen, with hæmorrhagic spots, and bleed
on the slightest touch. Erosions, sores, and ulcers are not uncommon;
the tongue is dry and furred, and the mouth exhales a fœtid odour. The
teeth may become loose in their sockets. Swelling of the joints ... may
be noticed, and lameness or stiffness from muscular or intermuscular
extravasation. Blood effusions into ... the eye have been noticed, and
paralytic or comatose symptoms from similar effusions on the brain. In
the absence of improvement the patient becomes more and more debilitated
and exhausted, and death may be preceded by profuse exhausting
diarrhœa.”
“=Prognosis= is unfavourable in advanced cases, and when the faulty
regimen cannot be corrected.”
=Treatment.= “The first consideration is to correct the unwholesome
conditions of life, purify the building and its surroundings, and allow
a free range on pasture. Subject each patient to a thorough soapy wash,
and if possible allow clean running water in which a bath may be taken
at will. Access to green food and invertebrates (slugs, larvæ, etc.) is
important, or a varied diet of grain, middlings, bran, roots, fruits,
tubers, cabbage, silage, etc., must be furnished. Iron and bitters
(gentian, nux vomica) are useful, and sometimes small doses of arsenite
of soda solution or cream of tartar are useful. Acorns or
horse-chestnuts are recommended. For the mouth a wash of potassium
chlorate, soda biborate, or potassium permanganate may be resorted
to.... In the case of fat pigs it is more profitable to butcher at once,
as soon as early symptoms appear.” From Law’s “Veterinary Medicine,” p.
558, Vol. III.
SECTION II.
DISEASES OF THE DIGESTIVE APPARATUS.
SEMIOLOGY OF THE DIGESTIVE APPARATUS.
The group of diseases which affect the digestive apparatus is one of the
most important in bovine pathology, because almost all animals of the
bovine species are bred with the object of utilising to the full their
powers of digestion and assimilation.
Whether we consider adult fat animals, calves intended for slaughter or
milch cows, the object sought is always the same—_i.e._, to secure the
greatest possible economic return through the medium of the digestive
functions.
Even although in working oxen there is no tendency to overfeeding, the
animals remain none the less predisposed to diseases of the digestive
apparatus; the meal times are often too short, and rumination has to be
performed under the yoke or during work—in a word, under unfavourable
physiological conditions.
=Semiology.= To ensure correct diagnosis it is necessary here, perhaps
more than in any other department of pathology, to be capable of
grasping the symptoms or syndromes and signs afforded by the different
parts of the digestive apparatus; to know how to co-ordinate and group
them so as logically to deduce the final synthesis, the diagnosis. The
diagnosis proving correct, the prognosis becomes easy, and this is the
chief object from the economic standpoint. The practitioner who
undertakes treatment knows how to deal with the case, and the owner
likewise knows what he undertakes to do.
Although this classification may appear arbitrary, we shall consider
successively diseases of the mouth, of the pharynx, œsophagus, stomach,
intestines, etc., firstly describing the symptoms characterising these
diseases. At the same time we should state that many symptoms are common
to a large number of diseases and in themselves have absolutely nothing
characteristic. They are simply sign-posts capable of showing the way.
=Mouth.= External examination reveals the condition of the muzzle, the
lips and their commissures, and the surroundings of the buccal opening,
and detects the existence of any desquamation, rents, eruptions,
ulcerations, etc., which may be present.
In quiet animals the practitioner can examine the cavity of the mouth
single-handed, but in troublesome animals it becomes necessary to have
an assistant, who seizes the muzzle with one hand and the tongue with
the other, or who simply fixes the animal’s head. In exceptional cases
it will be necessary to secure the patient to a post, tree, or wall. The
mere attempt at examination will show whether there is trismus or
absolute freedom of movement in the jaws.
[Illustration: $1]
By introducing the fingers between the commissures and applying them to
the bars or to the free portion of the tongue, the practitioner will be
able approximately to estimate the local and general temperature. The
sensations experienced will also inform him of the degree of moisture or
dryness of the mouth and of its sensibility.
On separating the jaws, he will note the odour exhaled and its possible
abnormalities—its acid, sourish, fœtid, or putrid character. He will
directly observe any anæmia or hyperæmia of the mucous membrane, from
the inner surface of the lips and cheeks up to the soft palate, although
owing to the thickness of the buccal epithelium it is not always easy to
estimate anæmia or hyperæmia in the ox. The surface of the tongue should
also be examined, and a note made whether it appear dry, pasty, dusty,
sooty, etc., though these appearances are occasionally apt to lead one
astray. The observer should also inquire regarding want of appetite,
depraved or exaggerated appetite, etc.
Even the manner in which the animal picks up its food will serve to
direct his attention to the development, or possible existence, of some
disease of the mouth, although want of appetite is not always
characteristic of a lesion in the pharynx or œsophagus, but sometimes of
a lesion in its neighbourhood, like hypertrophy of the retro-pharyngeal
or bronchial lymphatic glands.
This examination will also detect the existence on the lips of wounds,
cuts, injuries or specific eruptions (aphtha, tuberculous ulcerations,
the ulcerations of gangrenous coryza, etc.) on the gums indications of
gingivitis, periostitis, mercurial poisoning, actinomycosis of the
maxilla, and ulcerations of all kinds; on the tongue, of wounds, of
simple or specific inflammatory eruptions (aphtha, the ulcerations of
actinomycosis, tuberculosis, gangrenous coryza, etc.), as well as the
swellings due to superficial or deep-seated glossitis. By the same
method of examination, though with somewhat more difficulty, one can
detect abnormal mobility, irregularity of development, caries, etc., of
the teeth, the condition of the excretory ducts of the salivary glands,
the state of the hard and soft palate, and the existence of fissures,
vegetations, polypi and tumours.
[Illustration: $1]
=Salivary glands.= The salivary glands, particularly the parotid and
submaxillary, should be examined by direct inspection and palpation.
Direct inspection reveals the existence of swellings, deformity of
parts, increase in salivation, or ptyalism, which sometimes occur in
conjunction with foot-and-mouth disease, actinomycosis, acute stomatitis
and mercurial poisoning, as well as increase in size of the salivary
ducts.
Palpation reveals the degree of sensibility of the parts, the existence
of œdema, induration, cysts, and, more frequently, distension of the
salivary ducts as well as the presence of calculi, tumours, the
direction of fistulæ, etc.
Difficulties may occur, particularly when the submaxillary and parotid
glands are affected; but methodical and complete examination will
usually enable one to differentiate the conditions.
=Pharynx.= The pharynx may be examined externally by inspection and
palpation, and internally by direct digital palpation. Inspection
reveals possible deformities of the region of the gullet, palpation the
condition of the tissues as well as abnormal sensibility and
infiltration. Internally, digital examination must be cautiously
conducted, and after a strong gag has been securely inserted in the
mouth. Under such conditions it is without danger. The hand being
inserted exactly in the median line will detect obstructions which may
already have been partly identified by external palpation, as well as
the existence of inflammation with or without the formation of false
membranes, and of ulcerations, polypi, etc.
=Œsophagus.= In consequence of its anatomical formation, situation and
course, the œsophagus may be divided into two distinct parts—viz., the
cervical, which can be examined from the outside, and the thoracic,
which cannot so be examined.
The cervical part may be examined by inspection, by palpation from one
side, or by palpation with both hands and from both sides.
[Illustration: $1]
Inspection leads to the detection of changes in the shape of the
œsophagus and of the jugular furrow. In fat subjects, however, it is of
little value. As the position and the course of the œsophagus are known,
unilateral palpation, or, better still, bilateral palpation, employing
both hands, is of very much greater service. These methods reveal the
presence of swellings, infiltrations, changes in shape and sensibility,
the presence of foreign bodies, the existence of dilatations or
contractions of the tube, etc.
Auscultation and percussion, though recommended by some practitioners,
are not of much service.
Inability to swallow, due to change in the œsophagus, is also detected
by inspection. Its existence suggests a number of possible conditions,
such as fissure or ulceration of the œsophagus, compression in the
mediastinal region as a result of tuberculous or other disease,
contraction or dilatation of the œsophagus, etc. Furthermore, inspection
will betray the existence of dilatation of the tube, to which vomiting
and regurgitation of food are sometimes due.
Internal exploration is the only method of detecting changes in the
thoracic portion, and may also be utilised to locate lesions in the
cervical region. It is practised by passing a sound of small calibre or
any flexible cylindrical object, such as a cart rope, etc. The patient
must be fixed with the head extended on the neck and a proper gag or
speculum introduced into the mouth. Exploration assists us in
recognising the existence of inflammation of the œsophagus, true or
false contraction, dilatation and the presence of obstructions.
In animals of the bovine species all these lesions—viz., inflammation of
the œsophagus, fissuring and ulceration, obstructions, compressions,
dilatations and contractions of the tube—although not very frequent, are
nevertheless from time to time encountered.
=Stomach.= Exploration of the stomach or of the different gastric
compartments presupposes an exact knowledge of the respective positions
of the different reservoirs. Topographical anatomy shows that the rumen
is situated in the left flank, and that it occupies the whole of the
left abdominal region from the diaphragm to the pelvic cavity. As a
consequence, it may be explored from the region of the twelfth rib; it
is inclined slightly from above downwards, and from left to right, its
extreme right border extending as far as, or a little beyond, the white
line.
The reticulum, the smallest of the four reservoirs, is situated in the
sub-ensiform region at right angles to the median plane of the body. On
the left it touches the rumen and the diaphragm; on the right side it is
in contact in front with the diaphragm, above with the omasum, and to
the right and towards the rear with the abomasum. The omasum is situated
above the reticulum and conical right portion of the rumen; in front it
touches the liver, and towards the back and left the rumen. The abomasum
is situated obliquely in the right hypochondriac region, its anterior
surface resting on the lower wall of the abdomen towards the middle and
right side of the body, its pyloric portion extending upwards, behind
the right hypochondriac region.
=Rumen.= The rumen can be examined by inspection, palpation, percussion,
and auscultation. The use of the œsophageal sound and of the trocar and
canula is also of value in diagnosis.
Inspection affords information of a varying character, according to the
moment when it is practised, even in a condition of health. It only
extends to the condition of the flank before or after a meal, etc.,
emptiness of the rumen being accompanied by hollowness of the flank, and
distension, following an abundant meal, by fulness in this region.
When digestion is not proceeding normally, the flank may be distended
unduly by gaseous accumulations or by the presence of solid food. In
abdominal and mediastinal tuberculosis and in gastro-enteritis there may
be simple tension or slight dilatation. When indigestion or enteritis is
entering on a favourable stage, the flank may appear hollow, and in
cases of chronic diarrhœa it may appear retracted.
[Illustration: $1]
Digital examination or palpation may be practised over the entire region
of the flank. It shows whether the rumen is full or empty, reveals the
consistence of the contained food in cases of chronic indigestion, the
sensibility of the walls, and the rate and order of the muscular
contractions. Direct or indirect percussion may be carried out on a
horizontal line from the twelfth rib as far back as the flank, and
vertically from the lumbar vertebræ to the white line. In health one
discovers in young animals an upper zone of normal resonance due to gas,
a zone of semi-dulness and an inferior zone of absolute dulness, due to
the liquids in the rumen. The spleen, which is attached to the
supero-anterior surface of the left side of the rumen, does not
seriously restrict the area open to percussion.