Definition.—Strangles is an infectious disease of the horse, mule, and ass, seen most frequently in young animals, and usually leaving them immune from future trouble of the same kind.

It appears as a fever lasting for a few days, and is usually associated with an abscess formation of lymph glands, especially those under the jaw, which have a tendency to break on the outside. It usually leaves the animal after convalescence perfectly healthy and as good as it was before, but sometimes leaves it a roarer or is followed by the development of deep-seated abscesses which may prove fatal.

Causes.—The cause of strangles is infection by direct contact with an animal suffering from the disease, or indirectly through contact with the discharges from an infected animal, or by means of the atmosphere in which an infected animal has been. There are many predisposing causes which render some animals much more subject to contract the disease than others. Early age, which has given it the popular name of colt-ill, offers many more subjects than the later periods of life do, for the animal can contract the disease but once, and the large majority of adult and old animals have derived an immunity from previous attacks. At 3, 4, or 5 years of age the colt, which has been at home, safe on a meadow or in a cozy barnyard, far from all intercourse with other animals or sources of contagion, is first put to work and driven to the market town or county fairs to be exposed to an atmosphere or to stables contaminated by other horses suffering from disease and serving as infecting agents. If it fails to contract it there, it is sold and shipped in foul, undisinfected railway cars to dealers' stables, equally unclean, where it meets many opportunities of infection. If it escapes so far, it reaches the time for heavier work and daily contact on the streets of towns or large cities, with numerous other horses and mules, some of which are sure to be the bearers of the germs of this or some other infectious disease, and at last it succumbs.

The period of the eruption of the last permanent teeth, or the end of the period of development from the colt to an adult horse, at which time the animals usually have a tendency to fatten and be excessively full-blooded, also seems to be a predisposing period for the contraction of this as well as of the other infectious diseases. Thoroughbred colts are very susceptible, and frequently contract strangles at a somewhat earlier age than those of more humble origin. Mules and asses are much less susceptible and are but rarely affected. Other animals are not subject to this disease, but there is a certain analogy between it and distemper in dogs. After exposure to infection there is a period of incubation of the disease, lasting from two to four days, during which the animal enjoys its ordinary health.

Symptoms.—The horse at first is a little sluggish if used, or when placed in its stable is somewhat dejected, paying but moderate attention to the various disturbing surroundings. Its appetite is somewhat diminished in many cases, while in some cases the animal eats well throughout. Thirst is increased, but not a great deal of water is taken at one time. If a bucket of water is placed in the manger the patient will dip its nose into it and swallow a few mouthfuls, allowing some of it to drip back and then stop, to return to it in a short time. The coat becomes dry and the hairs stand on end. At times the horse will have chills of one or the other leg, the fore quarters, or hind quarters, or in severe cases of the whole body, with trembling of the muscles and dryness of the skin.

If the eyes and mouth are examined the membranes are found reddened to a bright rosy color. The pulse is quickened and the breathing may be slightly accelerated. At the end of two days a cough is heard and a discharge begins to come from the nostrils. This discharge is at first watery; it then becomes thicker, somewhat bluish in color, and sticky, and finally it assumes the yellowish color of matter and increases greatly in quantity.

At the outset the colt may sneeze occasionally and a cough is heard. The cough is at first repeated and harsh, but soon becomes softer and moist as the discharge increases. Again, the cough varies according to the source of the discharge, for in light cases this may be only a catarrh of the nasal canals, or it may be from the throat, the windpipe, or the air tubes of the lungs, or even from the lungs themselves. According to the organ affected the symptoms and character of cough are similar to those of a laryngitis, bronchitis, or lung fever caused by ordinary cold.

Shortly after the discharge is seen a swelling takes place under the jaw, or in the intermaxillary space. This is at first puffy, somewhat hot and tender, and finally becomes distinctly so, and an abscess is felt, or having broken itself the discharge is seen dripping from a small opening. When the discharge from the nostrils has fully developed the fever usually disappears and the animal regains its appetite, unless the swelling is sufficient to interfere with the function of the throat, causing pain on any attempt to swallow. At the end of four or six days the discharge lessens, the soreness around the throat diminishes, the horse regains its appetite, and in two weeks has regained its usual condition. Old and strong horses may have the disease in so light a form that the fever is not noticeable; they may continue to eat and perform their ordinary work as usual and no symptom may be seen beyond a slight discharge from the nose and a rare cough, which is not sufficient to worry any but the most particular owner. But, on the other hand, the disease may assume a malignant form or become complicated so as to become a most serious disease, and even prove fatal in many cases. Inflammation of the larynx and bronchi, if excessive, produce violent, harsh coughing, which may almost asphyxiate the animal. The large amount of discharge may be mixed with air by the difficult breathing, and the nostrils, the front of the animal, manger, and surrounding objects become covered with a white foam. The inflammation may be in the lung itself (lobular pneumonia) and cause the animal to breathe heavily, heave at the flanks, and show great distress. In this condition marked symptoms of fever are seen, the appetite is lost, the coat is dry, the horse stands back in its stall at the end of the halter strap with its neck extended and its legs propped apart to favor breathing. This condition may end by resolution, leaving the horse for some time with a severe cough, or the animal may die from choking up of the lungs (asphyxia).

The swelling under the jaw may be excessive, and if the abscess is not opened it burrows toward the throat or to the side and causes inflammation of the parotid glands and breaks in annoying fistulas at the sides of the throat and even up as high as the ears. Roaring may occur either during a moderately severe attack from inflammation of the throat (larynx), or at a later period as the result of continued lung trouble. Abscesses may develop in other parts of the body, in the poll, in the withers, or in the spaces of loose tissue under the arms, in the fold of the thigh, and, in entire horses, in the testicles.

During the course of the disease, or later, when the animal seems to be on the road to perfect recovery, abscesses may form in the internal organs and produce symptoms characteristic of disease of those parts.

Roaring, plunging, wandering in a circle, or standing with the head wedged in a corner of the stall indicate the collection of matter in the brain. Sudden and severe lung symptoms, without previous discharge, point to an abscess between the lungs, in the mediastinum; colic, which is often continuous for days, is the result of the formation of an abscess in some part of the abdominal cavity, usually in the mesentery.

Pathology.—The lesions of strangles are found on the surface of the mucous membranes, essentially of the respiratory system, and in the loose connective tissue fibers of the internal organs and glands, and consist of acute inflammatory changes, tending to the formation of matter. The blood is unaltered, though it is rich in fibrin, and if the animal has died of asphyxia it is found dark colored and uncoagulated when the body is first opened. If the animal has died while suffering from high fever the ordinary alterations throughout the body, which are produced by any fever not attended by alteration of blood, are found.

Prevention.—Healthy horses should be separated from the infected animals, and the stables in which the disease has occurred should be thoroughly disinfected. Since the disease frequently occurs annually on infected premises, systematic disinfection should be practiced after an outbreak. The stables, as well as all utensils which might have come in contact with the infection, should be thoroughly disinfected. By such practices recurrences of the disease may be prevented.

Treatment.—Ordinary light cases require but little treatment beyond diet, warm washes, moistened hay, warm coverings, and protection from exposure to cold. The latter is urgently called for, as lung complications, severe bronchitis, and laryngitis are often the results of neglect of this precaution. If the fever is excessive, the horse may receive small quantities of Glauber's salt (handful three times a day) as a laxative, bicarbonate of soda or niter in one-dram doses every few hours, and small doses of antimony, iodid of potash, aconite, or quinin. Steaming the head with the vapor of warm water poured over a bucket of bran and hay, in which belladonna leaves or tar have been placed, will allay the inflammation of the mucous membranes and greatly ease the cough.

The swelling of the glands should be promptly treated by flaxseed poultices and bathing with warm water, and as soon as there is any evidence of the formation of matter it should be opened. Prompt action in this will often save serious complications. Blisters and irritating liniments should not be applied to the throat. When lung complications show themselves the horse should have mustard applied to the belly and to the sides of the chest. When convalescence begins great care must be taken not to expose the animal to cold, which may bring on relapses, and while exercise is of great advantage it must not be turned into work until the animal has entirely regained its strength.

Bacterial vaccines are now being extensively used for the prevention and treatment of this disease. They are prepared from the specific germ of the disease and frequently exert a very beneficial influence. A serum is also being prepared from horses, which is injected with gradually increasing doses of this germ. This serum possesses considerable curative value and may prove especially valuable in cases in which the animals have failed to respond to other forms of treatment, or when valuable animals are affected with the disease.

PURPURA HEMORRHAGICA.

Definition.—This disease is a septic bacterial intoxication, acute and infectious in character, and is manifested by edematous swellings of the subcutaneous connective tissue, and hemorrhages on the mucous membrane and in the internal organs.

A previous attack of influenza is a common predisposing cause of this disease, which appears most frequently a few weeks after convalescence is established. It occurs more frequently in those animals which have made a rapid convalescence and are apparently perfectly well than it does in those which have made a slower recovery.

Anasarca commences by symptoms which are excessively variable. The local lesions may be confined to a small portion of the animal's body and the constitutional phenomena be nil. The appearance and gravity of the local lesions may be so unlike, from difference of location, that they seem to belong to a separate disease, and complications may completely mask the original trouble.

In the simplest form the first symptom noticed is a swelling, or several swellings, occurring on the surface of the body—on the forearm, the leg, the under surface of the belly, or the side of the head. The tumefaction is at first the size of a hen's egg; not hot, little sensitive, and distinctly circumscribed by a marked line from the surrounding healthy tissue. These tumors gradually extend until they coalesce, and in a few hours we have swelling of the legs, legs and belly, or the head, to an enormous size; they have always the characteristic constricted border, which looks as if it had been tied with a cord. In the nostrils are found small reddish spots, or petechiæ, which gradually assume a brownish and frequently a black color. Examination of the mouth will frequently reveal similar lesions on the surface of the tongue, along the lingual gutter, and on the frænum. If the external swelling has been on the head, the petechiæ of the mucous membranes are liable to be more numerous and to coalesce into patches of larger size than when the dropsy is confined to the legs. The animal may be rendered stiff by the swelling of the legs, or be annoyed by an awkward swollen head, which at times may be so enormous as to resemble that of a hippopotamus rather than that of a horse. During this period the temperature remains normal; the pulse, if altered at all, is only a little weaker; the respiration is only hurried if the swelling of the head infringes on the caliber of the nostrils. The appetite remains normal. The animal is attentive to all that is going on, and, except for the swelling, apparently in perfect health.

In from two to four days, in severe cases, the tissues can no longer resist the pressure of the exuded fluid. Over the surface of the skin which covers the dropsy we find a slight serous sweating, which loosens the epidermis and dries so as to simulate the eruption of some cutaneous disease. If this is excessive we may see irritated spots which are suppurating. In the nasal fossæ the hemorrhagic spots have acted as irritants, and, inviting an increased amount of blood to the Schneiderian membrane, produce a coryza or even a catarrh. We may now find some enlargement and peripheral edema of the lymphatic glands, which are fed from the affected part. The thermometer indicates a slight rise in the body temperature, while the pulse and respiration are somewhat accelerated. The appetite usually remains good. In the course of a few days the temperature may have reached 102°, 103°, or 104° F.

Fever is established, not an essential or specific fever in any way, but a simple secondary fever produced by the dead material from the surface or superficial suppuration, and by the oxidization and absorption of the colloid mass contained in the tissues. The skin may suppurate or slough more or less over the areas of greatest tension or where it is irritated by blows or pressure. The great swelling about the head may by closure of the nostrils interfere seriously with breathing. Internal edema may occur in the throat, lungs, or intestines. Septicemia, or blood poisoning, may result from anasarca.

Terminations.—The simple form of the disease most frequently terminates favorably on the eighth or tenth day by resolution or absorption of the effusion, with usually a profuse diuresis, and with or without diarrhea. The appetite remains good or is at times capricious.

Death may occur from mechanical asphyxia, produced by closure of the nostrils or closure of the glottis. Metastasis to the lungs is almost invariably fatal, causing death by asphyxia, Metastasis to the intestines may cause death from pain, enteritis, or hemorrhage.

Excessive suppuration, lymphangitis, and gangrene are causes of a fatal termination by exhaustion. Mortal exhaustion is again produced by inability to swallow in cases of excessive swelling of the head.

Peritonitis may arise secondary to the enteric edema, or by perforation of the stomach or intestines by a gangrenous spot. Septicemia terminates fatally with its usual train of symptoms.

Alterations.—The essential alterations of anasarca are exceedingly simple; the capillaries are dilated, the lymphatic spaces between the fibers of the connective tissue are filled with serum, and the coagulable portion of the blood presents a yellowish or citrine mass, jellylike in consistency, which has stretched out the tissue like the meshes of a sponge. Where the effusion has occurred between the muscles, as in the head, these are found dissected and separated from each other like those of a hog's head by the masses of fat. The surface of the skin is desquamated and frequently denuded of the hair. Frequently there are traces of suppuration and of ulceration. The mucous membrane of the nose is found studded with small, hemorrhagic spots, sometimes red, more frequently brown or black, often coalesced with each other in irregular-sized patches and surrounded by a reddish zone, the product of irritation. If edema of the intestines has occurred, the membrane is found four or five times its normal thickness, reddish in color, with hemorrhages on the free surface. Edema of the lungs leaves these organs distended. The secondary alterations vary according to the complications. There are frequently the lesions of asphyxia; externally we find ulcers, abscesses, and gangrenous spots and the deep ulcers resulting from the latter. The lymphatic cords and glands are found with all the lesions of lymphangitis. Again are found the traces of excessive emaciation, or the lesions of septicemia. Except from the complications the blood is not altered in anasarca.

Diagnosis.—The diagnosis of anasarca must principally be made from farcy or glanders. In anasarca the swelling is nonsensitive, while sensitive in the acute swelling of farcy. The nodes of farcy are distinct and hard and never circumscribed, as in the other disease. The eruption of glanders on the mucous membranes is nodular, hard, and pelletlike. The redness disappears on pressure. In case of excessive swelling of the head in anasarca, there may occur an extensive sero-fibrinous exudation from the mucous membranes of the nose, poured out as a semifluid mass or as a cast of the nasal fossæ, never having the appearance or typical oily character which it has in glanders. The inflammation of the lymphatic cords and glands in anasarca does not produce the indurated character which is found in farcy.

Prognosis.—While anasarca is not an excessively fatal disease, the prognosis must always be guarded. The majority of cases run a simple course and terminate favorably at the end of 8 or 10 days, or possibly, after one to two relapses, requiring several weeks for complete recovery. Effusion into the head renders the prognosis much more grave from the possible danger of mechanical asphyxia. Threatened mechanical asphyxia is especially dangerous on account of the risk of blood poisoning after an operation of tracheotomy. Edema of the viscera is a most serious complication. The prognosis is based on the complications, their extent, and their individual gravity, existing, as they do here, in an already debilitated subject.

Treatment.—The treatment of anasarca may be as variable as are the lesions. The indications are at once shown by the alterations and mechanism of the disease, which we have just studied.

Hygiene comes into play as the most important factor. Oats, oat-and-hay tea, milk, eggs—anything which the stomach or rectum can be coaxed to take care of—must be employed to give the nutriment, which is the only thing that will permanently strengthen the tissues; they must be strengthened in order to keep the capillaries at their proper caliber.

Laxatives, diaphoretics, and diuretics must be used to stimulate the emunctories so that they may carry off the large amount of the products of decomposition which result from the stagnated effusions of anasarca. Of these the sulphate of soda in small, repeated doses, the nitrate of potash and bicarbonate of soda in small quantity, or the chlorate of potash in single large doses will be found useful. Williams cites the chlorate of potash as an antiputrid. Stimulants and astringents are directly indicated. Spirits of turpentine serves the double purpose of a cardiac stimulant and a powerful, warm diuretic, for the kidneys in this disease will stand a wonderful amount of work. Camphor can be used with advantage. Coffee and tea are two of the diffusible stimulants which are too much neglected in veterinary medicine; both are valuable adjuncts in treatment of anasarca, as they are during convalescence at the end of any grave disease which has tended to render the patient anemic. Dilute sulphuric and hydrochloric acids are, perhaps, the best examples of a combination of stimulant, astringent, and tonic which can be employed. The simple astringents of mineral origin, sulphates of iron, copper, etc., are useful as digestive tonics; I doubt whether they have any constitutional effect. The vegetable astringents, tannic acid, etc., have not proved efficacious in my hands. Iodid of potash in small doses serves the triple purpose of digestive tonic, denutritive for inflammation, and diuretic. Among the newer forms of treatment are diluted Lugol's solution injected into the trachea, anti-streptococcus serum and colloidal silver solution injected into the circulation. No one but a qualified veterinarian would be competent to apply these remedies.

Externally.—Sponging the swollen parts, especially the head, when the swelling occurs there, is most useful. The bath should be at an extreme of temperature—either ice cold to constrict the tissues or hot water to act as an emollient and to favor circulation. Vinegar may be added as an astringent. When we have excessively denuded surfaces, suppuration, or open wounds, disinfectants should be added to the wash.

In cases of excessive swelling, especially of the head, mechanical relief may be required. Even in country practice, punctures of the part should be made with the hot iron, as no other disease so predisposes to septic contamination. When mechanical asphyxia is threatened tracheotomy may be demanded. With the first evidence of dyspnea, not due to closing of the nostrils or glottis, or with the first pawing which gives rise to a suspicion of colic, a mustard plaster should be applied over the whole belly and chest. The sinapism will draw the current of the circulation to the exterior, the metastasis to the lungs or intestines is prevented, and the enfeebled nervous system is stimulated to renewed vigor by the peripheral irritation. The organs are encouraged by it to renewed functional activity; the local inflammation produced by it favors absorption of the exudation. The objection to the use of blisters is their more severe action and the danger of mortification. Septicemia, when occurring as a complication, requires the ordinary treatment for the putrid diseases, with little hope of a good result.

After recovery the animal regains its ordinary health, and there is no predisposition to a return of the disease.

HORSEPOX, OR EQUINE VARIOLA.

Definition.—Horsepox is a specific, infectious fever of the horse, attended by an eruption of pustules, or pocks, over any part of the skin or on the mucous membranes lining the various cavities in the body, but chiefly, and often exclusively, upon the pasterns and fetlocks. The eruption may commence upon the lips, or about the nostrils or eyes.

This disease was described by the early Roman agricultural writers and by the veterinarians of the eighteenth century. It received its first important notice from the great Jenner, who confounded it with grease in horses, since animals with this disease are very liable to have the eruption of variola appear on the fetlocks. He saw these cases transmit the disease to cattle in the byres and to the stablemen and milkmaids who attended them, and furnish the latter with immunity from smallpox, which led to the discovery of vaccination. Horsepox is also frequently mistaken for the exanthemata attending some forms of venereal disease in horses.

Variola in the horse, while it is identical in principle, general course, complications, and lesions with variola in other animals, is a disease of the horse itself, and is not transmissible in the form of variola to any other animal; nor is the variola of any other animal transmissible to the horse. Cattle and men, if inoculated from a case of horsepox, develop vaccinia, but vaccinia from the latter animals is not so readily reinoculated into the horse with success. If it does develop, it produces the original disease.

Causes.—The direct cause of horsepox is infection. A large number of predisposing causes favor the development of the disease, as in the case of strangles, and this trouble, like almost all contagious diseases, renders the animal which has had one attack immune. The chief predisposing cause is youthfulness. Old horses which have not been affected are less liable to become infected when exposed than younger ones. The exposure incident to shipment, through public stables, cars, etc., acts as a predisposing cause, as in the other infectious diseases. The period of final dentition is a time which renders it peculiarly susceptible.

Dupaul states that the infection is transmissible through the atmosphere for several hundred yards. The more common means of contagion is by direct contact or by means of fomites. Feed boxes and bridles previously used by horses affected with variola are probably the most frequent carriers of the virus, and we find the lesions in the majority of cases developed in the neighborhood of the lips and nostrils. Coition is a frequent cause. A stallion suffering from this disease may be the cause of a considerable epizootic, as he transmits it to a number of brood mares and they in turn return to the farms where they are surrounded by young animals to which they convey the contagion. The saddle and croup straps are frequent agents of infection. The presence of a wound greatly favors the inoculation of the disease, which is also sometimes carried by surgical instruments or sponges. Trasbot recites a case in which a set of hobbles, which had been used on an animal suffering from variola, were used on a horse for a quittor operation and transmitted the disease, which developed on the edges of the wound.

Symptoms.—There is a period of incubation, after an animal has been exposed, of from five to eight days, during which there is no appreciable alteration in the health. This period is shorter in summer than in winter. At the end of this time small nodes develop at the point of inoculation and the animal becomes feverish. The horse is dull and dejected, loses its appetite, and has a rough, dry coat with the hairs on end. There is moderate thirst. The respirations are somewhat quickened and the pulse becomes rapid and full. The body temperature is elevated, frequently reaching 104° or 105° F. within 36 or 48 hours from the appearance of the first symptoms.

The visible mucous membranes, especially the conjunctivæ, are of a bright rosy red. In the lymphatic, cold-blooded, and more common horses these symptoms of fever are less marked; even with a comparatively high temperature the animal may retain its appetite and work comparatively well, but these cases, if worked and overheated, are liable to develop serious complications.

At the end of from three and a half to four days the eruption breaks out, the fever abates, and the general symptoms improve. The eruption in severe cases may be generalized; it may be confined to the softer skin of the nose and lips, the genital organs, and the inside of the thighs, or it may be localized in the neighborhood of a wound or in the irritated skin of a pair of greasy heels. It consists of a varying number of little nodes which, on a mucous membrane, as in the nostrils or vagina, or on soft, unpigmented skin, appear red and feel at first like shot under the epidermis. These nodes soften and show a yellowish spot in the center when they become pustules. The epidermis is dissolved and the matter escapes as a viscid fluid at first citrine and later cloudy and purulent, which dries rapidly, forming scabs; if these fall off or are removed they leave a little shallow, concave ulcer which heals in the course of five or six days. In the softer skin if pigmented the cicatrices are white and frequently remain so for about a year, when the pigment returns. The lips or genital organs of a colored horse, if covered with a number of small white spots about the size of a pea, will usually indicate that the animal has been affected with the horsepox.

At times the pustules may become confluent and produce large, superficial, serpentine ulcers on the membrane of the nostrils, around the lips or eyelids, or on the borders of wounds and in greasy heels; in this case the part becomes swollen, hot, painful, and is covered with a profuse discharge of matter. In this form there is frequently a secondary fever lasting for a day or two.

In severe cases there may be a suppurative adenitis, or inflammation of the lymphatic glands which are fed from the affected part. If the eruption is around the nostrils and lips, the glands between the jaws (submaxillary) form abscesses as in a case of strangles; if the eruption is in a pair of greasy heels abscesses may form in the fold of the groin (inguinal). There may be so much tumefaction of the nostrils as to produce difficulty in breathing.

Complications.—A case of horsepox may be attended with various complications of varying degrees of importance. Adenitis, or suppuration of the glands, has just been mentioned. Confluent eruptions irritate the part and induce the animal to rub the inflamed part against the manger or scratch it in other ways and thus produce troublesome ulcers, which may leave ugly scars. Irritation of the mucous membrane of the nose causes severe coryza with purulent discharge.

The eruption may occur in the throat or in the air tubes to the lungs, developing an acute laryngitis or bronchitis. If the animal is exposed to cold, or worked so as to engorge the lungs with blood at the termination of the specific fever, just when the eruption is about to localize, it may be determined to the lungs. In this case we have a short, dry cough, labored breathing, the development of a secondary fever of some gravity, and all the external symptoms of a pneumonia. This pneumonia differs, however, from an ordinary pneumonia in the symptoms furnished by the examination of the lungs themselves. In place of a large mass of the lung tissue being affected the inflammation is disseminated in smaller spots over the entire lung.

Diagnosis.—The diagnosis of horsepox is to be based on the presence of a continuous fever, with rosy mucous membranes, for several days and the appearance of the characteristic eruption. If the eruption is in the nasal cavities, marked by a considerable discharge and attended with submaxillary abscesses, it may be confounded with strangles. If the throat is affected, it may be confounded with an angina (laryngitis or pharyngitis), but in the latter the local trouble precedes or is concomitant with the fever, while in the former the fever precedes the local trouble by several days. Variola may be confounded with bronchitis or pneumonia if complicated with these troubles and the eruption is absent from the exterior, but it is of little moment, as the treatment for both is much the same. When the eruption is in the neighborhood of the genital organs the disease has been mistaken for dourine. In variola the eruption is a temporary one; the nodes and pustules are followed by shallow ulcers and rapid cicatrization unless continued in the vagina or on the penis by the rubbing of the walls and filth which accumulates; there are apt to be pustules at other parts of the body. In the venereal disease the local trouble commences as a papule and breaks into an ulcer without having formed a pustule. The ulcer has not the convex rosy appearance of that of the less serious discharge; the symptoms last for a longer period, by which time others aid in differentiating the two. In glanders the tubercle is hard and, after breaking into an ulcer, the indurated bottom remains, grayish or dirty white in color, ragged, and exuding a viscous, oily discharge. There is no disposition to suppuration of the neighboring glands. In variola the rosy shallow ulcer and healthy pus, with the acutely tumefied glands, should not be mistaken, at least after a day. I have seen in mules acute glanders which required a day's delay to differentiate from strangles; at that time the farcy buds appeared.

Prognosis.—The average case of horsepox runs a course of dejection, loss of appetite, and more or less fever for about four days, followed by a rapid convalescence, and leaves the animal as well and as sound as before. If the eruption has been excessive or confluent, the ulcerations may act as irritants and render the animal unfit for use for several weeks. Laryngitis, pharyngitis, bronchitis, and pneumonia in this disease are not of greater gravity than they are when occurring from other causes. The spots denuded of pigment left by the pustules on the lips and genitals may temporarily depreciate the value of the animal to a slight degree.

Treatment.—As this is a disease unattended by alterations of the blood itself, although a specific fever, and is of a sthenic type, active remedies are admissible and indicated. The horse should be placed on a low diet (little or no oats)—bran mashes, a moderate quantity of good, sound hay, a few carrots or apples, which will act as laxatives; also slop feed. Barley flour is more cooling for mashes than bran or oatmeal. Water may be given as the animal desires it, but it should not be cold; if a half bucketful of water is kept in the manger, the horse will take but a few swallows at a time. One-dram doses of nitrate of potash or 1-ounce doses of sweet spirits of niter are useful in the drinking water. If the fever is high, the antipyretics are indicated: Sulphate of quinin in 1-dram doses; iodid of potash in 1-dram doses; infusion of pine tops, of juniper leaves, of the aromatic herbs, or of English breakfast tea are useful in the later stages. If complications of the air passages or lungs are threatened, a large mustard poultice should be applied to the belly and sides of the chest. Oxid of zinc ointment should be used on confluent eruptions, and if the ulceration is excessive it may have to be touched with caustic.

Great care must be taken to keep the animal protected from cold drafts of air or other exposure. Blankets or sheets should be used on the body and bandages on the legs. After convalescence is established, nutritious feed of easy digestion and walking exercise are all that is needed, except perhaps a little Glauber's salt to prevent constipation.

Prophylactic treatment.—When horsepox breaks out among a large number of horses, especially on a farm where there are a number of colts, it may be assumed that the greater majority will contract the disease, and it is more economical that they should have it and be through with it at once. If the weather is moderate, all the animals which have not been affected can be inoculated, which will produce the disease in a mild form, with the eruption at a point of election, and render the danger of complication a minimum one. For inoculation the discharge from the pustules of a mild case should be selected and inoculated by scarification on the belly or the under surface of the neck.

ANTHRAX.

Definition.—Anthrax is a severe and usually fatal contagious disease, characterized by chills, great depression and stupor of the animal, and a profound alteration of the blood. It is caused by the entrance into the animal's body of a bacterium, known as the Bacillus anthracis, or its spores.

Practically all animals are susceptible to anthrax. The herbivora are especially susceptible, in the following order: The sheep, the ox, and the horse. The guinea pig, the hog, the rabbit, mice, and other animals die quickly from its effects. Man, the dog, and other omnivora and carnivora may be attacked by it in a constitutional form as fatal as in the herbivora, but fortunately in many cases develop from it only local trouble, followed by recovery.

Anthrax has been a scourge of the animals of the civilized world since the first written history we have of any of their diseases. In 1709-1712 extensive outbreaks of anthrax occurred in Germany, Hungary, and Poland. In the first half of the nineteenth century it had become an extensively spread disease in Russia, Holland, and England, and for the last century has been gradually spreading in the Americas, more so in South America than here. In 1864, in the five governments of Petersburg, Novgorod, Olonetz, Twer, and Jaroslaw, in Russia, more than 10,000 horses and nearly 1,000 persons perished from the disease.

Causes.—The causes of anthrax were for a long time attributed entirely to climatic influence, soil, and atmospheric temperature, and they are still recognized as predisposing factors in the development of the disease, for it is usually found, especially when outbreaks in a great number of animals occur, in low, damp, marshy countries during the warm seasons. It is more frequent in districts where marshy lands dry out during the heat of summer and are then covered with light rains. Decaying vegetable matter seems most favorable for nourishing and preserving the virus.

The direct cause of anthrax is always infection of a previously sound animal, either directly from a diseased animal or through various media which contain excretions or the débris from the body of one previously infected.

The specific virus of anthrax was first discovered by Davaine in 1851. He recognized microscopic bodies in the form of little rods in the blood of animals suffering from anthrax. It was not, however, till a quarter of a century later that Pasteur defined the exact nature of the bacillus, the mode of its propagation, and its exact relationship to anthrax as the sole cause of the disease. In the animal body the bacilli have a tendency to accumulate in the spleen, liver, and elsewhere, so that these organs are much more virulent than the muscles or less vascular tissues. When eliminated from the animal in the excretions, or when exposed to outside influences by the death of the animal and the disintegration of the tissues, the body of the rod is destroyed and the spores only remain. These spores, which may be called the seeds of the bacilli, retain their vitality for a long period; they resist ordinary putrefaction; they are unchanged by moisture; and they are not affected by moderate heat. If scattered with the débris of a dead animal on the surface of the ground, they may remain around the roots of the grass in a pasture or may be washed to the nearest low-lying ground or marsh. If buried in the body of an animal dead from anthrax, they may be washed deep into the ground, and in later years (in one proved case 17 years) be brought to the surface and infect other animals. They are frequently brought to the surface of the earth, having been swallowed by earthworms, in the bodies of which they have been found.

This accounts for the outbreaks at the time of the first rains after a dry season. During the latter the earthworm goes deep in the ground in search of moisture; it finds the spore which has been washed there in past years, swallows it, and afterwards brings it to the surface. The virus is carried with the wool from infected sheep and remains in it through the process of manufacture into cloth. The spores remain in the hides of animals which have died of anthrax and retain their vitality throughout months of soaking in the tanners' pits, the working of the harness maker or the cobbler, and after the oiling of the completed leather. The dried spores in the dust from any of these products may be carried by the atmosphere.

Infection of an animal takes place through inoculation or contact of the bacillus or its spores with an abraded surface or mucous membrane, on a sound animal. In an infected district horses may eat with impunity the rich pasturage of spring and early summer, but when grass gets low they crop it close to the ground, pull up the roots around which the virus may be lodged, and under these conditions the animals are more apt to have abrasions of the lips or tongue by contact with dried stubble and the dirt on the roots; this favors the introduction of the germs into the system. The virus may be introduced with feed and enter the blood-vessel system from the stomach and intestines. If in the dust, dried hay, or on the parched pasture of late summer, the virus may be inhaled and be absorbed from the lining of the lungs. If in harness leather, it needs but an abrasion of the skin, as the harness rubs it, to transfer the spore from the leather to the circulation of the animal.

The writer saw a case of anthrax occur in a groom from the use of a new horse brush. The strap which passes over the back of the hand inoculated an abrasion on the knuckle of the first finger, and in 12 hours a "pustule" had formed and the arm had become infected.

Symptoms.—The symptoms of anthrax usually develop with extreme rapidity. The horse is dejected and falls into a state of profound stupor, attended with great muscular weakness. The feeble, indolent animal, if forced to move, drags its legs. There are severe chills, agitation of the muscles, symptoms of vertigo, and at times colicky pains. The mucous membranes turn a deep ocher or bluish-red color. The body temperature is rapidly elevated to 104° or 105° F. The breathing is increased to 30 or 40 respirations in the minute and the pulse is greatly accelerated, but while the arteries are soft and almost imperceptible, the heart beats can be felt and heard, violent and tumultuous. In some cases, when inoculation is through the skin, large subcutaneous swellings appear; these may involve a leg, a shoulder, one side of the body, or the neck or head. The swelling is at first hot and painful, but afterwards it becomes necrotic and sensation is lost. The symptoms last but two, three, or four days at most, when the case usually terminates fatally. An examination of the blood shows a dark fluid which will not clot, and which remains black after exposure to the air. After death the bodies putrefy rapidly and bloat up; the tissues are filled with gases, and a bloody foam exudes from the mouth, nostrils, and anus, and frequently the mucous membranes of the rectum protrude from the latter. The hairs detach from the skin. Congestion of all the organs and tissues is found, with interstitial hemorrhages. The muscles are friable and are covered with ecchymotic spots. This is especially marked in the heart.

The black, uncoagulated, and incoagulable blood shows an iridescent scum on its surface, which is due to the fat of the animal dissolved by the ammonia produced by the decomposed tissues. The serum oozes out of every tissue and contains broken-down blood, which, when examined microscopically, is found to have the red globules crenated and the leucocytes granular. A high power of the microscope also reveals the bacteria in the shape of little rodlike bodies of homogeneous texture with their brilliant spores.

The lymphatic ganglia are increased four, five, six, or ten times their natural size, enlarged by the engorgement of blood. The spleen shows nodulated black spots containing a muddy blood, which is found teeming with the virus. This organ is much enlarged and is quite friable. The mucous membranes of the intestines are congested and reddish brown; the surface of the intestines is in many places denuded of its lining membrane, showing fissures and hemorrhagic spots. The liver has a cooked appearance; the kidneys are congested and friable; the urine is red; the pleura, lungs, and the meninges are congested, and the bronchi of the lungs contain a bloody foam.

Treatment.—Treatment of anthrax in animals by medicinal means has not proved satisfactory. In cases of local anthrax an incision of the swelling followed by the application of disinfectants sometimes causes good results. In such cases, however, the danger of disseminating the infection from the wounds tends to make this procedure inadvisable unless great care is taken.

Good results are obtained from the use of serum in the treatment of the disease. For this purpose 30 to 100 cubic centimeters should be administered subcutaneously or intravenously. If no improvement is noticed within 24 hours the injection should be repeated. In a number of instances afforded to test the curative value of the serum in cases of anthrax in man and animals splendid results were obtained.

The prophylactic treatment formerly consisted in the avoidance of certain fields and marshes which were recognized as contaminated during the months of August and September and had been occupied the years in which the outbreaks usually occurred. It underwent, however, a revolution after the discovery by Pasteur of the possibility of a prophylactic inoculation or vaccination which granted immunity from future attacks of the disease similar to that granted by the recovery of an animal from an ordinary attack of the disease.

This treatment consists in the use of a vaccine which is made by the artificial cultivation of the virus of anthrax in broth and in the treatment of it by means of continued exposure to a high temperature for a certain time, which weakens the virus to such extent that it is capable of producing only a very mild and not dangerous attack of anthrax in the animal in which it is inoculated, and thus protects it from inoculation of a stronger virus. The production of this virus, which is carried on in some countries at the expense of the governments and is furnished at a small cost to the farmers in regions where the disease prevails, in this country is made in private laboratories only.

At the present time very good results are being obtained with vaccination consisting of an injection of highly potent anthrax serum on one side of the animal and a vaccine on the other side. This method of treatment requires only a single handling of the animals and further possesses advantages over the Pasteur treatment in that it immediately makes animals immune. In the numerous applications of this form of treatment very good results have been obtained and the immunity produced thereby visually lasts at least one year. The vaccinated animals should be kept for a period of ten days to two weeks from exposure, since during that period they are at times even more susceptible to the disease, and therefore care should be taken not to reduce their vitality.

Prevention.—In attempts to control the disease it is essential, aside from protective vaccination, to prevent the reinfection of localities. For this purpose it is essential, if possible, to drain thoroughly and keep under cultivation the infected areas before animals are permitted to pasture on them. The complete destruction of all anthrax carcasses is also very important. This is best accomplished by burning, but as this method of disposal is impracticable in many localities, deep burial may be found to be better. Covering the carcasses within their graves with quicklime adds another valuable precaution against further dissemination of the infection. No animal dying from anthrax should ever be skinned or cut open, as the blood from these sources is one of the most dangerous means of spreading the infection, being charged, while in the animal, with great numbers of bacilli, which quickly turn into spores as soon as spread about upon the face of the ground. All discharges from the body openings should also be burned or buried deeply, as they are frequently of a virulent character.

GLANDERS AND FARCY.

(Pls. XL-XLII.)

Definition.—Let it be understood at the outset that glanders and farcy are one and the same disease, differing only in that the first term is applied to the disease when the local lesions predominate in the internal organs, especially in the nostrils, lungs, and air tubes, and that the second term is applied to it when the principal manifestation is an outbreak of the lesions on the exterior or skin of the animal. The term glanders applies to the disease in both forms, while the term farcy is limited to the visible appearance of external trouble only; but in the latter case internal lesions always exist, although they may not be evident.

Glanders is a contagious constitutional disease of the genus Equus (the horse, ass, and mule), readily communicable to man, the dog, the cat, the rabbit, and the guinea pig. It is transmitted with difficulty to sheep and goats, and cattle seem to be entirely immune. It runs a variable course and usually produces the death of the animal affected with it. It is characterized by the formation of neoplasms, or nodules, of connective tissue, which degenerate into ulcers, from which exude a peculiar discharge. It is accompanied with a variable degree of fever, according to the rapidity of its course. It is subject to various complications of the lymphatic glands, of the lungs, of the testicles, of the internal organs, and of the subcutaneous connective tissue.