Chapter IV: Front Matter (4)

_Symptoms._ 1. _Acute Form._ There is a sudden marked rise of temperature, often to 107° F., with acceleration of pulse and respiration. Sometimes death follows so early as to prevent the observation of other symptoms. If otherwise there supervene marked dulness, prostration, somnolence, anorexia, suspension of rumination, and more or less tympany of the rumen. The patient is found lying down, apart from the flock, indisposed to rise, with deep red, congested, arborescent conjunctiva and other mucous membranes, and petechial spots on these and on the white portions of the skin. The fæces, at first moderately firm and moulded in pellets, marked here and there with lines of mucus, or even blood, become on the second or third day soft, pultaceous, or watery and highly offensive. Parallel with this, emaciation advances with rapid strides. Breathing becomes more hurried, wheezing or snuffling, with a muco-serous, often bloody discharge from the nose, and an infrequent cough. Careful auscultation and percussion will often reveal the blowing or mucous râles, the crepitation or flatness on percussion of broncho-pneumonia. As the disease advances the petechiæ on skin and mucosæ extend, and extensive deep violet areas show especially on the inner sides of the arms and thighs, on the under surface of the tail, on the perineum and under the belly. Abortion is a common result, the lambs coming dead.

Death may occur in six hours, more commonly in two or three days, or even longer, the temperature going down to below normal in the last stages. In case of recovery, convalescence is slow, the animal remaining emaciated and weak, with lung lesions and persistent cough for a length of time. These poor imperfectly recovered animals continue to harbor the microbe and transmit it. Lesions of the liver and other organs, the result of this disease, are found in sheep that have survived the affection and are afterward killed for mutton.

_Symptoms: 2. Subacute and Chronic Form._ This is seen in mature sheep of two or three years, that have been infected when in the full vigor of life and health, during an open air life and by a limited dose of the virus. The temperature is less elevated, the circulatory and respiratory functions less disturbed, the dulness and prostration only moderate, the interruption of feeding and rumination transient and tympany slight. Cough and nasal discharge are however present and rather persistent, diarrhœa may be manifested, and marked emaciation occurs. There may be congestion of the mucosæ, but petechiæ and extensive bloody discoloration of the mucous membranes or skin are rarely seen. Abortion is not uncommon.

Recoveries are the rule in this type of the disease, though in some cases it will be delayed for weeks and may even then be imperfect.

_Lesions._ In the acute types of the disease decomposition advances rapidly after death, and the carcass from the first exhales a peculiarly heavy odor. The skin is discolored, the nasal mucosa is the seat of a muco-purulent or sanguinolent discharge, the anus is soiled with liquid fæces, the subcutaneous connective tissue marked by red arborescence and blood-stained areas, or by a gelatinoid exudation, the muscles at times deeply colored and petechiated, the lymph glands, especially the bronchial and mesenteric, are enlarged and congested of a deep red—the color being highest in the cortical zone. In some old standing cases these may have softened and acquired a grayish hue. They are rich in the specific bacterium.

The peritoneum is congested, petechiated, thickened, and more or less covered with thin false membranes, and it contains from a pint to three quarts of a sero-sanguinolent liquid which coagulates loosely on exposure. The liver is congested, with points of blood extravasation, and zones of degeneration (fibroid, fatty or necrotic), and sometimes abscess. The congestion extends to the spleen and pancreas. The abomasum and intestines are the seat of mucous gastro-enteritis. The mucous folds of the pyloric sac of the stomach are congested, reddened and petechiated, the small intestine has tracts and patches of congestion, thickening and softening, Peyers’ patches and the solitary glands are enlarged, and ulcers may be present on large or small intestines.

Effusion is usually found in the pleura, clear, grayish or bloody, with flocculi and false membranes, and further branching redness of the serosa. The mediastinum may be thickened by exudate especially around the glands, œsophagus and blood vessels. The lung shows lobular, interlobular and peribronchial exudates approaching at times to the appearances shown in lung plague, along with the atelectasis, emphysema and, in prolonged cases, caseation.

Less constant are congestions and petechiæ of the pericardium, heart, kidneys, vesical mucosa, testicles, ovaries or womb. The blood is dark and forms a loose coagulum. In case of abortion the umbilical cord is infiltrated and the placental membranes ecchymotic. The brain and spinal cord and their membranes are sometimes congested and infiltrated and a serous effusion exists in the arachnoid.

The bacterium is found more or less abundantly in each of the morbid lesions.

_Prevention._ Absolute seclusion of the sick and of all their products is the prime essential. The general distribution of the lesions throughout the body and the uniform presence of the bacterium in the lesions indicate that no part of the body and no secretion can be considered as free from infection. All parts of the body, all expectoration, saliva, fæces, urine, milk even must be withheld from all other animals, at least until they have been thoroughly cooked or disinfected. Manure must be burned, or buried deeply in quicklime. Contaminated pens, yards, wallows, streams and fields must be abandoned or thoroughly disinfected.

Galtier found that the virus remained active for six days in putrefying organic matter at 39° to 75° F.; in 25 days in water, at room temperature; the refuse litter, fodder, manure, and drainage matter from the infected place must be carefully guarded against. The virus steadily loses in force in such media, but remains infecting to animals injected with it. The most active disinfectants may be used on the pens and yards (copperas 5%, sulphuric acid 2% solution, or mercuric chloride .2%) while the contaminated fields should be abandoned for the season. All droppings may be treated with sulphuric acid (2%), creolin, lysol, phenic acid or copper sulphate. The susceptibility of practically all the animals of the farm, demands the exclusion of these, while that of rodents, renders necessary the further exclusion of wild mammals; and we may add birds, wild and tame, and if possible flies. The plowing of the contaminated soil will do much to obviate danger, yet the sheep folds and pastures should be separated by a considerable distance from any place where infected animals and objects have been. If drinking troughs for sound animals have been used by the sick or suspected they should be emptied and washed with a disinfectant (sulphuric acid 2:100).

ULCERATIVE (ERYSIPELATOID) INFECTION OF THE LIMBS IN CATTLE AND SHEEP.

New York outbreaks. Causes: wounds by sharp pebbles, streptococci,
pure cultures, inoculations. Symptoms: swelling on lower limbs,
abscesses, implicating tendons, bones, joints, and under hoof.
Prevention: avoid septic or frosted mud, irritants, etc., disinfect
surface, keep dry and clean, open abscesses, use disinfectants,
separate infected.

This affection was seen in several herds in Oneida Co., N. Y., in the Spring of 1897. The geological formation of the region was a calcareous rock with a surface soil thickly impregnated with pebbles and small flat shaly masses. Sheep suffered in Western New York.

_Causes._ In Oneida, the subjects were dairy cows, which in the early spring, when the frost went out of the ground, had to wade through chilly soft mud reaching to the knees or above, and mixed with small stones with sharp edges, and with semiliquid manurial products. The abrasions made by these stones furnished convenient infection atria for septic microbes in the manure. In the pus obtained from the ulcers were found in abundance the bacillus coli commune, and a long streptococcus representing on an average from 20 to 40 cocci in a chain. Dr. Moore made pure cultures of these and produced the same symptoms in a cow by injecting the streptococcus subcutaneously in the back of the pastern, and in another animal by simply abrading the surface and rubbing on the streptococcus culture. As the inflammation, suppuration, and resulting ulcers implicated not only the skin but also the subcutaneous connective tissue, the affection had many of the characters of erysipelas.

_Symptoms._ The affection commenced by swelling in the region of the fetlock, pastern, metacarpus or metatarsus, and exceptionally, the forearm or tibial region, and advanced to a tense swelling, which pitted on pressure, and the formation of centres of suppuration, which burst and discharged. If the exposure to the septic mud were continued the sores ulcerated and extended both in the skin and subcutaneous connective tissue, but when the dry weather came and the mud disappeared, the tendency was to spontaneous recovery. In some instances ulceration extended beneath the hoof threatening its evulsion, and in other cases it extended deeply to the tendons and ligaments.

_Treatment._ The main object should be prevention, to be secured by protecting the stock against contact with septic mud, and especially such as is near the freezing point and intermixed with such sharp stones and pebbles as would wound the surface and open channels for infection. When infection has taken place we should seek to limit it by lotions of an antiseptic character. Bandages soaked in a solution of hyposulphite of sodium, 1 dr. to the ounce will often succeed. A more potent application is iodized phenol, prepared as follows: tincture of iodine 2 drs., carbolic acid crystals 4 drs., glycerine 1 oz., alcohol 1 oz., water 8 ozs. When applied on a bandage this may be diluted with water to make 1 pint. For circumscribed application to forming sores the undiluted iodized phenol, made of one part each of iodine and carbolic acid crystals, may be applied twice a day with a glass rod. Other favorite applications are a lotion of lead and laudanum; a saturated solution of boric acid; ninety-five per cent. alcohol; a mixture of creolin 1 part, iodoform 4 parts, and lanolin 10 parts; ichthyol and collodion; ichthyol and vaseline; or iodol, iodoform, salicylic acid or resorcin as dusting powders.

Internally, tincture of muriate of iron 3 drms. every three hours helps to keep the affection in check.

GANGRENOUS INFECTION OF THE CORONET. HORSE. POTCHETCHOUI.

Seen on rich, damp lands. Symptoms: lameness, small areas of
congestion, erection of hairs, vesiculation, pustulation, gangrene as
deep as tendons, depilation, desquamation, fistulæ, slough of hoof,
early fever, impaired appetite, recovery in 14 to 21 days in most
cases. Staphylococcus and streptococcus. Prevention: segregation,
different attendants, avoidance of infecting land while damp, smear
limbs with antiseptics. Treatment: antiseptic bandages.

Under this name Sotsevich describes an infectious disease of the horse, which prevails in the Don province, and especially on rich, low, damp lands. Before the appearance of any local lesion, the horse goes very lame on one limb. Afterward there appears, usually on the coronet or pastern, an area on which the hairs stand erect, with elevation of the epidermis and the formation of vesicles as large as barley corns, filled with a yellowish white liquid and later with pus. Gangrene follows, extending from the skin to the subcutaneous connective tissue, aponeurosis and tendons, and forming large sores, one to two inches in diameter and discharging an abundant yellow, fœtid pus. The adjacent skin takes on a yellow tint and sheds its hair and epidermis. The disease may extend into the interphalangean joints or under the hoof, leading to offensive fistulæ or evulsion of the hoof. If it extends to the higher parts of the limb it becomes less destructive.

At the onset there is some fever (101° F.), dulness and inappetence, but these gradually subside, and in favorable cases complete recovery has taken place in two or three weeks.

Bacteriological investigation has detected in the contents of the vesicles, staphylococcus pyogenes aureus, and streptococcus pyogenes.

_Prevention_ is largely secured by a rigid separation of the diseased from the healthy. Other obvious precautions would be to exclude those dressing the sores from handling other horses until after thorough disinfection of the hands, and to keep the sound animals, during wet seasons, from the damp infecting soils, or when they must work on these, to smear the lower parts of the limbs with antiseptic ointments (tar, carbolic, iodine, mercuric, etc., etc.)

_Treatment_ with sublimate bandages proves very satisfactory, yet any comparatively non-irritating antiseptic lotion may be used.

STRANGLES, INFECTIOUS RHINO-ADENITIS.

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.

CONTAGIOUS PNEUMONIA IN THE HORSE.