Synonyms. Definition. Historic notes. Bacteriology: streptococcus
coryzæ contagiosæ equi in pus, chains of 3 and upward, free cocci,
arthrospores, clumps, ærobic, growing freely in serum, or glycerined
bouillon; pathogenic to horse and white mouse; relation to other
streptococci; clinical evidence; accessory causes, youth, primary
susceptibility, dentition, training, impure stable air, grain ration,
excitement, sudation, fatigue, chill, change of climate, trading,
crowding, sea voyage, catarrh of air passages. Infecting products,
pus, ingesta, blood, manure, fodder, litter, water, secretion of
mucosa of healthy. Wounds, castration, mangers, racks, troughs,
buckets, poles, shafts, harness, halters, twitches, blankets, rubbers,
combs, brushes, men, etc. Pathology: infection of lymphatics, through
inhalation, sore, ingestion, congenital, milk; congestion of nasal
mucosa, epithelial degeneration and desquamation, discharge little
viscid, corded lymphatics rare, submaxillary swelling rarely small or
nodular, pus creamy, indolent cases, pharyngeal, thoracic, buccal,
gastro-intestinal, hepatic, pancreatic, splenic, muscular, arthritic,
cutaneous, nervous. Forms: mild, malignant, regular, irregular.
Incubation 3 to 5 days. General symptoms: hyperthermia, dulness,
apathy, costiveness. Specific symptoms: nasal, congestion, sneezing,
purulent discharge; epiphora, submaxillary phlegmon; pharyngeal and
laryngeal; parotidean; pulmonary; abdominal, hepatic, pancreatic,
splenic, perirenal, cutaneous, genital, nervous, septicæmic.
Diagnosis, from catarrh, glanders. Prognosis, favorable, apart from
malignancy. Prevention: exclude strange equine animals; avoid public
stables, yards, drinking troughs and buckets; also manure, stable
utensils, hay, fodder, litter, or watershed from infected places;
disinfect cars, wagons, etc. Seclude inmates of infected stable, yard,
park, etc., temporarily close public drinking and feeding places, make
sale or exposure of infected animal penal; temporarily close dealers’
stables; sale with general guarantee only. Disinfection. Immunization;
inoculation from mild case. Treatment: hygienic, antipyretic,
eliminating, antiseptic, surgical, tonic, antisuppurant.
_Synonyms._ Distemper; Coryza Contagiosa Equorum; Gourme (Fr.); Druse
(Ger.); Cimurro (Ital.).
_Definition._ An infective, streptococcic, febrile disease of solipeds,
usually manifested by a catarrhal inflammation of the upper air
passages, and phlegmon of the adjacent lymph glands, or less frequently
by phlegmonous inflammation of lymph glands elsewhere or of the skin.
_Historic Notes._ Strangles was fairly indicated in the writings of the
ancient Greek veterinarians, and was clearly described and attributed to
contagion by Solleysel in 1664. It was so evidently infectious that it
was experimentally inoculated by Lafosse in 1790, by Viborg, in 1802,
and later, by Erdelyi (1813) and Toggia (1823) and others. Rivolta, in
1873, found a streptococcus in the pus of its abscesses, and to this the
contagion was definitely assigned by Baruchello (1887), Schütz, Sand and
Jensen (1888). Priority in this demonstration is accorded to Schütz.
_Bacteriology._ The _streptococcus coryzæ contagiosæ Equi_
(Streptococcus rhino-adenitis or S. equi) is easily found in the pus of
gland abscesses sometimes in pure cultures (impure in the nasal
discharge), stains readily in aniline colors and in Gram’s solution so
that it stands out clearly among the pus cells. The decolorizing agent
must be weak (not muriatic acid) and applied only for a very short time.
Beside the chain forms, there are isolated, oval cocci, some of which,
larger than others and more elongated, have been held to be arthrospores
or mother cells. The number of elements articulated in a chain varies
from two to four and upward. The chains are straight or sinuous, and may
be grouped in bundles, radiating masses, or clumps like staphylococci.
They are ærobic (facultative anærobic), grow freely as transparent
droplets on blood serum at 99° F., and in glycerine bouillon, and less
vigorously on agar and gelatine. On agar the colonies reach the size of
a pin head in two days with projecting alæ, and on gelatine in three to
five days, and then dry and shrink. Multiplication takes place by
transverse division, and at such a time the organism may seem to be a
chain of diplococci.
_Pathogenesis._ Inoculation of cultures on a susceptible horse produces
the unquestionable phenomena of strangles, and solipeds alone take the
disease casually. In white mice it produces abscess in the seat of
puncture and in the adjacent lymph glands. If the action is delayed the
abscess may be in lung, spleen, kidneys, liver, or other distant organ.
Rabbits, Guinea pigs, pigeons, pigs and cattle are immune unless large
doses are employed. Intravenously large doses kill the lamb.
The _identity_ of the microbe with other streptococci of animals and man
has been claimed. Arloing alleges that, by culture of the microbe in the
blood or peritoneum of the live rabbit, he exalted the virulence, and
obtained in succession a streptococcus capable of producing
_erysipelas_; _gangrenous erysipelas_; _suppurating_, _sloughing
erysipelas_; _pseudo-membranous peritonitis_; _metastatic abscesses_;
and _fulminant septic peritonitis_. Hill, Jensen and Sand, and
Lignieres, as the result of cultures and inoculations claim that
strangles streptococcus is identical with that of contagious pneumonia.
Courmont, on the other hand, as the result of his cultures and
inoculations, concludes that the microbe of strangles and that of
erysipelas are independent organisms.
The clinical evidence is decidedly against the theory of identity. In
epizoötics of strangles we meet with a constant succession of cases of
strangles and in districts into which contagious pneumonia has never
been introduced, no single case of that disease ever comes in to break
the monotony of the sequence and to start a series of cases of the
latter affection. Conversely, in an outbreak of contagious pneumonia in
a locality heretofore free from strangles, strangles do not develop.
Again, no matter how prevalent nor how constant strangles may be in a
locality, and how habitually men have their wounded hands covered with
the pus of the abscesses, no epidemic of erysipelas is entailed in man.
Strangles spreads with remarkable rapidity through a stable, but not to
the often more than equally exposed human attendants, nor to any animal
apart from the genus equus. The absence of strangles from Iceland
(Jonsson) endorses that view.
As a practical question of sanitary science, we occupy a sound position
in differentiating the germs of strangles and contagious pneumonia, and
further that of erysipelas of man, as a wise health officer would
differentiate the microbes of cowpox and smallpox. Whatever may be true
or false as to their primary identity, or as to the transition of one to
the other in successive inoculations on animals of other genera, they
are essentially diverse pathogenically as we meet with them in practice,
and our measures may be safely based on this practical diversity.
_Accessory Causes._ _Youth_ strongly predisposes, most cases occurring
between two and five years, and seventy per cent. before five years. It
may, however, appear at any age, being congenital in some cases (Nocard,
etc.), in others appearing a few weeks after birth, and in still others
at over twenty years, if the subjects have not contracted it earlier.
_Dentition_ which is active in these early years, induces congestion
about the head and general constitutional disturbance, which make the
system more receptive.
_Training_ or _breaking_ is another reason for the predisposition in the
young. The first experience of the _hot, impure, infected air_ of the
stable, the unwonted _grain feeding_, the _excitements_ and
_perspirations_ attendant on the first handling all contribute to
temporary loss of resistance.
_Fatigue_ like other weakening conditions lays the system open to
attack.
_Chill_ is a most efficient cause, hence the disease often prevails most
extensively in spring and autumn, at the time of changing the coat, and
of passing from stable to field and the converse. Joly relates that in
Russia where large numbers die of strangles through imperfect stabling
in winter, immunity is sought through a milder first attack, brought on
in the milder autumn weather by turning the young animals into a deep
pool for half an hour and then exposing them freely to cold winds and
giving cold water to drink. The omnipresent germ takes occasion to
attack the cold debilitated system.
Any _change of latitude_ or of locality acts in the same way. Riquet
even alleges that this will bring about a second and even a third
attack. It is common, he says, for newly bought young horses to have the
disease at Hamburg, and after recovery to have a second attack at
Hanover and finally a third one after they join the regiments in France.
A similar exhaustion of immunity has been repeatedly noticed in the case
of canine distemper.
_Horse trading_ and the _stabling of large numbers_ together is
naturally the most fruitful of infection and hence strangles is a
virtual plague in dealers’ studs. The buildings in such cases are
reinfected at short intervals with virulent types of the streptococcus,
and fresh susceptible animals are being constantly introduced to keep it
up. Riquet says that in Northern Germany dealers avoid this largely by
traveling their purchases in bands of 100 or 150 head, from ten to
twelve miles a day, feeding sparingly, and turning them like sheep into
an open park at night regardless of the weather. Much of the advantage
is doubtless from the avoidance of stable infection and the warm
relaxing air of indoors.
_A sea voyage_ especially favors infection and a single victim placed on
board will speedily contaminate all susceptible animals present.
Finally the predisposing influence of _catarrh of the air-passages_ must
not be overlooked. The inflamed mucosa furnishes a most inviting
infection entrance.
_Infecting products._ The streptococcus abounds in the local phlegmons
and abscesses, in the exudate of the submaxillary, pharyngeal or other
glandular swellings, in the pustular eruption on the skin, and in the
catarrhal discharge from the air passages. It further exists in the
alimentary canal, in the ingesta and in the blood to a limited extent.
In the bowels of an immunized animal it may remain virulent for months.
Thus it comes that the manure is a source of infection, and that soiled
fodder, litter and water may prove dangerous. The infected soil can not
only harbor but can multiply the microbe, keeping it in readiness to
attack any receptive horse. On his part the horse that is immune and in
vigorous health may carry the infection for months and transmit it to
his less resistant fellow.
While the streptococcus is usually found in the blood, in limited
numbers only, its presence there implies its general diffusion and
especially in the lymph plexuses and glands. Hence, the danger of
operations on the subjects of strangles, the weakened tissues of the
wound forming a most inviting field of growth. Castrations, occurring as
they do mostly in the growing animal, are especially to be guarded
against, and I may cite the case, familiar to many, in which seven
cryptorchids died with phlegmon in the seat of the wound, the first one
operated on having had strangles.
The nasal and buccal discharges are especially liable to convey the
infection through mangers, racks, fodders, drinking troughs and pails,
harness, poles and shafts, halters, twitches and the like. Infection
through blankets, brushes, rubbers, and the clothes and hands of
attendants, dealers, veterinarians and others, is not to be overlooked.
_Pathology._ The streptococcus shows a special disposition to enter and
advance along the lines of the lymphatic circulation. The paucity of the
germ in the blood and its abundance in the lymph plexuses, vessels and
glands show that its election is preëminently for the lymphatic system.
Then the ordinary primary lesions in and around the upper part of the
air passage (nose, pharynx, submaxillary, parotidean and pharyngeal
lymph glands) bespeak infection by inhalation, rather than with the
ingesta. Primary solitary lesions on or near stomach or intestine are
almost unknown; nearly all such being secondary. Next to inhalation, the
most prominent channel of entrance is through castration and other
wounds. Abrasions and sores of skin diseases must rank after wounds as
entrance channels. Transmission by copulation the microbe being lodged
on the genital mucosa is well established, also transmission from mother
to fœtus through the placenta, and from dam to offspring through the
milk.
In the most familiar type of the disease the nasal mucosa is red,
congested and somewhat thickened with exudate, and the epithelium is
softened and desquamating. As the result of this desquamation there may
be slight abrasions or raw sores but these do not show indications of
the irregular outline, excavations, or progressive extensions that
characterize the ulcers of glanders. The surface is usually plentifully
covered with a muco-purulent material with less disposition to
adhesiveness than in glanders. It is rare to see any exudate into, and
thickening of the walls of the lymphatics running from the nostrils
toward the submaxillary glands. The predominance of the streptococcus
in, and the entire absence of the glanders bacillus from the discharge
and inflamed mucosa are conclusive. In the regular cases in which the
submaxillary lymph glands are implicated, both right and left are
usually involved, though not to the same degree, the exudate fills not
only the gland tissue, but a large amount of the surrounding connective
tissue as well, there is a great accumulation of lymphoid cells, and
more or less extensive pus cavities, containing usually a white, creamy
product. In the early stages the glands may be hard and nodular, as in
glanders, but this condition is very transient, so that the rule is to
find an extensive surrounding exudation filling up the whole
intermaxillary space, and having a great abundance of small round cells
with double or triple nuclei. In the older cases there is usually the
open abscess, and if the case is an indolent one there may be extensive
organization of the exudate with formation of dense, fibrous tissue. In
some instances the nasal sinuses are filled with muco-pus.
When lesions extend farther implicating the pharynx and larynx, the
mucosa of these parts shows the same redness, congestion, cloudy
swelling and desquamation with, in some instances, small, submucous
abscesses, and in others extensive infiltration of the submucosa with
lymph so as to narrow or even close the lumen of the larynx. The
guttural pouches may be filled with pus though this is far from
constant. The pharyngeal lymph glands, are nearly always involved and
often the lymph gland in the parotid so that a general infiltration of
the surrounding parts is met with.
If the chest is implicated there is congestion of the bronchial mucosa,
engorgement of the smaller bronchia, air sacs and cells with pus,
collapse, carnification or congestion of lobules, in some cases
pulmonary abscess, and, finally, swelling and not infrequently abscess
of the bronchial glands. Pleurisy is a not uncommon accompaniment,
appearing it may be as a simple extension, from the lung, or, in the
worst forms, from rupture of mediastinal or glandular abscesses into the
cavity and severe infection of the entire pleural walls. The pericardium
is exceptionally involved and coagula on the tricuspid valves have been
met with (Zschokke).
Circumscribed phlegmonous exudates and small abscesses are sometimes
found in the mouth (tongue, soft palate, cheeks) and less frequently in
the œsophagus.
The stomach may show congestions, petechiæ, circumscribed hæmorrhages,
ulcers, and abscesses of the gland tissue or submucosa. Rupture of the
walls may follow abscess (Cadeac).
The intestines may show congestions, colorless or hæmorrhagic exudate,
and suppurations in the agminated or solitary glands, or submucosa. The
intestinal, mesenteric and sublumbar lymph glands may be the centres of
abscesses of varying sizes.
Abscesses may also be found in the liver, pancreas, spleen, of variable
size and usually as secondary formations.
The muscles and intermuscular tissue may be the seat of more or less
extensive exudation, and abscess, and the bones may be congested and
swollen especially in their epiphysis. This may extend to suppuration or
necrosis.
The synovial membranes of joints and the tendinous sheaths are not
infrequently inflamed causing distension and even suppuration.
Congestions of the skin are sometimes met with developing as multiple
papules or hard nodules which advance to the formation of pustules or
small abscesses. These often appear especially where the skin is thin
and delicate as around the lips, nose and eyes, close to the anus or
vulva, in the perineum, sheath or mammæ, inside the thighs or elbow.
They may be of all dimensions from a millet seed upward, and may merge
into or become complicated by the extensive engorgements of petechial
fever.
Finally lesions of the nerve centres are to be looked for in the
protracted or irregular types of the disease. There may be simple
congestion, or serous effusion, intraventricular or subarachnoid, or
finally abscess in the brain, spinal cord or meninges.
_Forms of Strangles._ The types of strangles vary, special forms
characterizing given epizoötics or seasons, or at other times as
individual deviations from the current type. Division has been made into
two groups—_mild_ and _malignant_, or again into _regular_ and
_irregular_, under each of which come several varieties. Many of these
varieties consist simply in a difference in the seat of the principle
lesions, which start in lymph glands or tissues at a distance from the
nasal mucosa, or they depend on secondary foci of infection supervening
on the primary disease in the head.
_Incubation._ In inoculated cases this lasts from three to five days, in
those due to simple exposure it may appear to extend over eight days.
_General Symptoms._ In nearly all cases alike there is a marked
constitutional disturbance the temperature often rising at once to 104°
to 106° F., and oscillating on successive days between this and 102°;
the pulse is usually normal at first and the breathing is either
slightly accelerated or may be made so under slight exertion. There is
more or less dulness, or at least a lack of the vivacity of youth, the
head is somewhat pendent, the eyes may be semiclosed, the patient may be
tardy or even stiff in his movements and the appetite may be diminished
or capricious, oats being rejected by some and hay or grass by others.
The bowels are somewhat confined, the stools consisting of a few small,
hard, balls covered with mucus.
_Specific Symptoms in the Mild Form._ In the vast majority of cases the
local symptoms are concentrated on the mucosæ of nose and mouth, and the
submaxillary lymph glands. Along with the general febrile phenomena,
there appear redness and often mottled congestion of the nasal mucosa,
which not infrequently extends to the mouth and eyes, as well. Heat of
the mouth, the collection of a more or less tenacious mucus, and even
uneasy movements of the jaw may be seen. The nasal mucosa, at first dry,
is soon the seat of a watery exudation, passing into a cloudy sticky
material, and finally a thick, opaque, muco-purulent flow. This may
become colored of a variety of tints, dirty white from inhaled dust,
brownish or yellowish from exuded blood, or greenish from food
materials. The discharge is usually profuse in the young and may be
scanty in the old. Most commonly it flows from both nostrils alike,
though exceptionally it is unilateral. In this it differs from glanders
which is more often unilateral though at times bilateral. Small
abrasions and sores may appear in connection with the softening and
shedding of the epithelium, but these are not ragged, irregular and
spreading as in glanders. Sneezing or snorting is an inevitable symptom.
Epiphora is usually present. Exudations into the nasal sinuses are to be
recognized by heat of the forehead and flat sound on percussion.
Very early in the attack a swelling is noticed in the intermaxillary
space, which may be at first confined to the nodules of the lymph
glands, thus forming distinct, rounded, hard swellings, but they are
early covered by a diffuse exudation into the surrounding connective
tissue, that completely envelopes and obscures the form of the swollen
glands, and forms a more or less uniformly rounded, pasty swelling,
extending to the median line of the intermaxillary space, or filling the
whole space from one maxilla to the other and projecting downward below
their level. This early, diffuse, pasty, evenly rounded swelling, hot
and tender, is distinctive of strangles, and usually exclusive of
glanders.
Another characteristic of the strangles swelling is its steady, and
usually speedy, advance to suppuration and abscess. It becomes hard,
tense, and resistant, then, in the centre, or at various points of the
surface, small areas of circumscribed softening can be detected, and
soon show distinct fluctuation. Two or more of these may coalesce or
they may form several distinct abscesses, which may early point, burst
and discharge, when the remainder of the exudate softens and degenerates
into pus, and the cavity closes by granulation. In some cases after the
formation of the swelling it disappears by resolution, the exudate
becoming liquefied and absorbed. In glanders the nodular, insensible,
swelling tends to persist without extensive pasty exudation or
suppuration.
Cases of _strangles catarrh_ in which the submaxillary lesions are
omitted, are quite common. These occur during the regular strangles
epizoötic, and protect against a second attack.
_Symptoms of Pharyngeal and Laryngeal Strangles._ Extension of the
morbid process from nose to pharynx is exceedingly common. When
concentrated on the pharynx there are extension of the head forward with
elevation of the nose, swelling of the throat laterally or downward,
uneasy movements of the jaws, salivation, difficulty of swallowing,
return of ingested liquids through the nose, gulping, and a loose
suffocative cough. The swelling of the throat tends to attain to large
dimensions, and may threaten suffocation by interfering with the
breathing. This is still further aggravated if the laryngeal mucosa is
the seat of exudate. The breathing may become loud and stertorous, the
mucosæ of a dark leaden hue and the animal dull and stupid from the
venous condition of the circulating blood.
Abscesses forming on the lateral parts of the throat usually make their
way to the surface though this may be below the level of the parotid. If
from the parotidean lymph gland, one of the ducts may be opened thus
forming a salivary fistula. If from the retro- (supra-) pharyngeal
glands the rupture into the pharynx is more likely to take place, but in
some cases the investing sac, meeting with equal resistance in all
directions, fails to undergo degeneration and softening at any one
particular point, and the contents remain pent up indefinitely. If the
liquid is absorbed a cheesy or putty like mass may be the final outcome,
with chronic cough, some stertor in breathing and it may be difficulty
in swallowing.
If the guttural pouches should be involved, there is deafness,
parotidean swelling, which may eventuate in a fluctuating swelling at
the lower border of the parotid, and a free discharge when the head is
lowered, which is likely to last after general recovery. (See Guttural
Pouches, pus in).
Laryngeal paralysis and roaring often follow laryngitis in strangles.
_Pulmonary Symptoms in Strangles._ _Tracheitis_ and _bronchitis_ are
forms of extension of strangles from the upper air passages, and
_pneumonia_ follows of virtual necessity. In many cases these are
primarily dependent on the descent into the lungs of the infecting
discharges, complicated in many cases by the inhalation of food
materials. There are the usual symptoms of broncho-pneumonia
complicating those of strangles and the percussion and auscultation
signs usually imply circumscribed areas of congestion and consolidation
with intervening areas of pervious lung. There may be at such points the
blowing or mucous râles of bronchitis, the sibilant sounds of emphysema,
the crepitation of congestion and the abnormal clearness of sounds
carried from distant organs through the consolidated lung. On percussion
there may be the non-resonance of the consolidated areas, and the excess
of resonance over emphysematous portions or open gas-filled vomicæ. In
these last cases there may be an amphoric sound on auscultation and a
crack-pot sound on percussion. These pulmonary lesions are often fatal,
or the recovery is slow on account of a succession of lobular
congestions and abscesses.
_Abdominal Symptoms in Strangles._ The abdominal lesions in strangles
are usually secondary, the infection reaching the part through the
blood, or by the lymphatics from a castration or other wound, or from
infection by coitus. The phlegmon and abscess may be in the mucosa,
especially in the agminated or solitary glands, in the adjacent lymph
glands at the connection with the mesentery and in those of the
mesentery itself. The animal is dull, listless, with dry, staring coat,
tympany and slight colicy pains after eating, costiveness, retracted,
tender abdomen, insensible loins, and groaning when rising, when walking
down a steep incline, or turning in a very narrow circle. These symptoms
following an apparent or partial recovery from strangles are
significant, and rectal examination may detect a hard, tender mass
connected with the bowel or mesentery.
If rupture takes place into the peritoneum there is general infective
inflammation of that structure with sudden access of fever, marked
prostration and an early death. In more favorable cases its adhesion to
the bowel or to the abdominal wall opens the way for rupture into the
gut or externally and there may be a slow healing of the cavity by
granulation. It may be a month or two before such an abscess opens and
for a length of time thereafter the health is poor, and the animal
lacking in condition and endurance.
When the abscess is formed in the _liver_ there is high fever with
shivering fits, irregularity of the bowels (bound up or loose), dusky or
yellowish hue of the visible mucosæ, anorexia, followed by peritoneal
infection or pyæmia (secondary abscesses).
Abscess of the _pancreas_ or _spleen_ is even less definite in symptoms.
These may terminate in rupture and peritonitis, or the splenic abscess
may become chronic and indolent and in a measure harmless.
_Perirenal Abscess_ is betrayed by specially sensitive loins, stiffness
and groaning in rising or in turning sharply on himself, drooping of the
back under a load, and by albuminous urine. In a small animal the part
may be reached and the tenderness ellicited by handling.
_Cutaneous Symptoms in Strangles._ Though by no means a common form,
strangles sometimes attacks the skin, more particularly that of the
face, head and neck, appearing in the form of pustules or small
abscesses, or it may be of a rounded nodular elevation, which may
disappear without forming either vesicle or pustule. The points of
election are around the lips, nose and eyes, upon the mucosa inside the
lips, along the line of the facial lymphatics running toward the
submaxillary gland, and at points where there is special friction, as
under the halter, collar, saddle, crupper, in the hollow of the heel,
under the tail, on the perineum, in the groin and axilla. They may
extend more or less up the limbs, or around the point of primary attack
attended by more or less engorgement. When this engorgement has reached
extensive dimensions and is mixed with sanguineous extravasation it is
considered as having merged into petechial fever.
_Symptoms of Coital Infection._ From four to seven days after copulation
there appear fever, dullness, stiffness, anorexia, swelling and heat of
the lips of the vulva, a yellowish opaque discharge from its lower
commissure, a deep dark red blush of the mucosa, with points of distinct
infiltration and thickening, developing into vesicles and pustules. The
perineum, the groin and mammæ often show an extension of the congestion
and eruption. In exceptional cases deep abscesses form and Letard
records a fatal case with extensive suppuration among the muscles of the
hind limbs and the haunch, inside the pelvis and along the line of the
aorta.
_Symptoms of Nervous Lesions._ The lesions of the brain and spinal cord
are usually secondary and often appear when the less dangerous
superficial manifestations, are tardy and indolent, when the exudates
are indurated and indisposed to soften. There may be violent delirium,
pushing of the head against the wall, movements of the limbs as if
walking or trotting, roaring, plunging, striking with fore or hind feet,
trismus or other muscular spasms. More frequently there is great
dulness, prostration, debility, vertigo, drowsiness, amaurosis,
paraplegia, general paralysis, coma. If the lesion is in the spinal cord
the spastic or paralytic symptoms are likely to be confined to the hind
parts.
_Fulminant or Septicæmic Form._ Bigoteau describes a rapidly fatal,
septicæmic form, with sudden onset, anorexia, extreme prostration,
uncertain stumbling gait, a deep blue color and ecchymosis of the
visible mucosæ, violent heart action, pulse weak and small, hurried
breathing (45 per minute) temperature 102° to 106° F., often inability
to rise and death from asphyxia in from two to five days.
_Diagnosis._ In mild and regular cases this is easy. The attack in rapid
succession of all the young, and still susceptible horses in a stable or
locality, and the uniform coincidence of a profuse nasal catarrh, and
the formation between the branches of the lower jaw, of a diffuse, hot,
painful swelling rapidly advancing to suppuration and discharge are
virtually conclusive. Simple catarrhs even if infective and attacking
all young horses do not cause phlegmon of the submaxillary lymph glands
as occurs in the great majority of cases of strangles. Glanders which is
attended by both nasal discharge and submaxillary swelling, is slower in
its onset, usually with little or no fever, has usually a more adhesive
discharge, ragged, unhealthy ulcers on the nasal mucosa with a
disposition to extend, often it shows cord-like thickening of the
lymphatics on the side of the face, and the submaxillary swelling is
smaller, made up of a number of small, hard, insensible rounded nodules
which show virtually no tendency to suppurate. (See diagnosis of
glanders). In cases of doubt it may be advisable to inoculate a
Guinea-pig and a white mouse. The Guinea-pig resists a small dose, while
the mouse forms abscess in the seat of inoculation in the dependent
lymph glands. The Guinea-pig is very susceptible to glanders, and the
white mouse immune. Or mallein may be used.
_Prognosis._ The mild type of strangles almost invariably terminates
favorably. In the irregular types with internal abscess the prospect is
grave in ratio with the size and multiplicity of the foci and the vital
importance of the organ invaded. In 15,421 cases collected by
Friedberger and Fröhner, and representing the total in a series of
outbreaks, but 3 per cent proved fatal. Much, however, depends on the
special potency of the germ. Horses contracting this in a particular
year or from a given stable in the same year convey the disease to
others in a malignant form, while others that contracted it in another
year or a different stable infect with the mild form only.
_Prevention._ In the older countries horsemen too often accept strangles
as inevitable. They expect that all horses will have it sooner or later,
and it is not worth while to guard against it. The too absolute doctrine
of the identity of the germ with the microbe of erysipelas, puerperal
fever, contagious pneumonia, influenza, of the suppurations of the limbs
and feet in sheep and cattle, and other streptococcic infections seems
to corroborate this view. But on the other hand the absence of strangles
from given countries like Iceland where erysipelas and its coadjutors
are common, its absence from secluded breeding farms and districts in
America, though prevailing all around them, the rapidity of its spread
when introduced in a sick colt, and the entire failure to extend in the
same way from an erysipelatous man to susceptible young horses with
which he comes in contact show that preventive measures may be
successfully applied for its restriction and extinction. The conceded
family resemblance of the microbes and the experimental production, by
their inoculation, of lesions showing many points of similitude leave
them still sufficiently distinct in their pathogenesis to warrant
measures for the suppression of the variety which produces strangles.
_Precautions for the private owner._ During the existence of strangles
in the district, _exclude strange horses, asses or mules_ from the farm
or stable. Keep young susceptible horses from _public stables or yards_
(livery, feeding, training, fair, market, and above all, dealers’ and
sale stables) and even from _public drinking troughs_ and _buckets_ used
in common. Provide against their contact with _manure_ from strange or
infected stables, or with _pastures_, _fields_ and _wagons_ on which
this has been put, also against the use around the stable or on fodder
of _forks_ or _other implements_ that have been used for such manure.
Avoid _hay_ or other _fodder_ or _litter_ from a strange barn or one
that is open to any suspicion of infection. Avoid _running water_ that
has drained land, stables, or yards where strange horses have been, or
those open to suspicion. In shipping by car or other _public conveyance_
disinfect the latter before the animal is loaded. If a _second hand
wagon, shafts, pole, harness, blanket_ or other object is brought on the
place or used, disinfect the same before using.
_Measures for Sanitary Police._ Make it _compulsory to report_, under
penalty for failure, all cases of strangles, or of horses with nasal
discharge, or submaxillary swelling. Forbid removal from the stable, or
secluded enclosure, of all horses, etc., suffering in this way or which
have been pronounced by the official veterinarian to have strangles.
Provide for _exclusion of all other solipeds_ from such _stables_, or
from _contact_ or _dangerous proximity_ to animals held in them, also
from _infected yards, parks, cars, boats, etc. Close public drinking
troughs_ during an epizoötic; let each owner use his own bucket.
Circumstances may demand closure of public feeding stables as well.
_Forbid_, under penalty, _sale_, _exposure_ or _movement_ on any _public
highway_ or _unfenced place_ of any infected (diseased or exposed)
soliped. Enjoin _certificate of sanitary conditions of stable and stud_
with each animal sold. _Close dealers’ stables_, or forbid any sale from
them until all infection has ceased and the buildings have been
thoroughly disinfected. Compel thorough _disinfection of stables, yards,
cars, boats and other public conveyances_ that may be open to reasonable
suspicion of infection.
_Immunization._ An attack renders the subject immune, but this may be
early overcome by marked change of location, and exposure to a virus of
greater intensity or modified quality. Besides the crude and reckless
Russian method already referred to, direct inoculation of the virulent
products has been often resorted to from the time of Gohier onward, in
the different countries of Europe. By selecting the matter from the
abscesses or nasal discharge of a mild epizoötic, and preserving the
inoculated subjects in clean, dry, pure aired stables, on nourishing
diet, and under the best conditions of hygiene, a fair measure of
immunity was conferred with absolutely no loss. The same as after casual
cases, second attacks will sometimes be shown, but even in severe
outbreaks, of a less violent type. The pus from the abscess, or the
preceding exudate in the swelling may be simply rubbed on the nasal
mucosa, or injected subcutem in another part of the body. In many cases
there follows merely a local cellulitis, while in others the general
infection leads to the nasal discharge, with or without the submaxillary
abscess.
This method is open to the individual owner where no concerted effort is
made to _stamp out_ the infection. When, however, police measures for
suppression are in force, it must be strictly prohibited, or adopted
only under official control, and with absolute seclusion and thorough
disinfection.
_Treatment._ In mild regular cases hygienic measures only are demanded.
Cleanliness, dry stalls, pure air, warmth (a sunny exposure if
available), nourishing, easily digested food, (grass, green corn stalks,
bran mashes, roots, carrots, turnips, apples, potatoes, ensilage,
scalded oats or hay) and pure water, or linseed tea, grooming and, in
cold weather, blanketing may suffice. Rest is indispensable, though
exercise may be allowed in a sheltered or sunny field or yard in fine
weather.
Castrations and all other surgical operations are forbidden.
For costiveness or tardy action of the bowels 1, 2 or 3 ozs. of sulphate
of soda may be allowed daily in the drinking water.
To soothe the inflamed air-passages it is well to steam them with the
vapor of hot water to which has been added an antiseptic such as oil of
tar, tar, phenic acid, or creolin. This may be placed in a bucket, and a
bag with its bottom cut so as to form a tube drawn over the bucket and
nose of the horse. It may be continued an hour or more at a time, or a
nasal douche of creolin (1:100) may be employed. In case of tardy
softening of the submaxillary swelling it may be assiduously fomented,
or covered with a linseed meal or other poultice to which a little
antiseptic (carbolic acid, creolin) has been added. It may be applied on
a cotton hood having holes for eyes and ears and furnished with ends to
tie back of the ears and down the middle of the face. If still indolent
the swelling may be rubbed with soap liniment or smeared with soft soap,
or finally a cantharides blister may be applied.
As soon as any indication of softening or fluctuation is detected a free
incision should be made to allow the exit of the pus. This further tends
to hasten the liquefaction and removal of the adjacent exudate. If the
pus lies near to the surface, with little more than skin to penetrate,
it may be freely incised with one thrust of the knife, but if there is
intervening glandular or other tissue, the skin only should be first
incised, and the connective tissue bored through with the finger nail,
or the point of a sterilized director, or of closed scissors. In this
way the important vessels, nerves and salivary ducts are pushed aside
and troublesome bleeding and saliva fistula alike avoided.
Fever usually subsides on the opening of the abscess, but if it fails to
do so, or if it reappears from slight absorption of septic matters it
may be desirable to favor elimination by small doses of sodium
bicarbonate, ammonium chloride, or potassium nitrate. In extreme cases a
few doses of acetanilid may be given, or full doses of quinia.
When the discharge from nose or abscess threatens to persist, such
agents as sulphur, yellow or black sulphide of antimony, are given with
bitters, but a more prompt effect can usually be had from injections of
weak solutions of creolin, cresyl, lysol, etc. When the cough is
troublesome it may be quieted by belladonna, or, in case of weakness of
the heart, by digitalis.
The various complications require treatment appropriate to their nature.
Collections of pus in the nasal sinuses may demand trephining and
antiseptic injections. Swellings about the throat threatening asphyxia
and which cannot be relieved by evacuation of pus may necessitate
tracheotomy until suppuration occurs. The cutaneous pustules and
abscesses are dealt with by pricking the collections and washing daily
or oftener with astringent antiseptics (phenic acid and alum).
Bronchitis and broncho-pneumonia may be benefited by sinapisms applied
to the sides of the chest, the internal administration of potassium
iodide, ammonium chloride, sodium hyposulphite, terpene or terpinol; or
by inhalation of weak sulphur fumes, or tar vapor.
For abscesses in the bronchial or mesenteric glands, the brain, spinal
cord, or other internal organ, little can usually be done but to sustain
the patient and await the course of events. If the abscess can be
accurately located it may be aspirated and then injected with an
antiseptic; if in the encephalon, trephining may be resorted to; death
is certain in such a case in the absence of treatment.
During convalescence it is very important to avoid overexertion and
chill, which are very liable to bring on petechial fever. Also, to feed
nourishing food, give pure air and water, and to see that no suspension
of action of bowels, or kidneys threatens to shut up toxins and waste
products in the system. _Apropos_ of impure water Williams quotes the
case of a foul stream near Bradford, England, on the banks of which
every case of strangles did badly.