WARTS.

These are essentially a morbid overgrowth of the superficial papillary layer of the skin and of the investing cuticular layer. They are mostly seen in young horses, about the lips, eyelids, cheeks, ears, beneath the belly, and on the sheath, but may develop anywhere. The smaller ones may be clipped off with scissors and the raw surface cauterized with bluestone. The larger may be sliced off with a sharp knife, or if with a narrow neck they may be twisted off and then cauterized. If very vascular they may be strangled by a wax thread or cord tied around their necks, at least three turns being made around and the ends being fixed by passing them beneath the last preceding turn of the cord, so that they can be tightened day by day as they slacken by shrinkage of the tissues. If the neck is too broad it may be transfixed several times with a double-threaded needle and then be tied in sections. Very broad warts that can not be treated in this way may be burned down with a soldering bolt at a red heat to beneath the surface of the skin, and any subsequent tendency to overgrowth kept down by bluestone.

BLACK PIGMENT TUMORS, OR MELANOSIS.

These are common in gray and in white horses on the naturally black parts of the skin at the roots of the tail, around the anus, vulva, udder, sheath, eyelids, and lips. They are readily recognized by their inky-black color, which extends throughout the whole mass. They may appear as simple, pealike masses, or as multiple tumors aggregating many pounds, especially around the tail. In the horse these are usually simple tumors, and may be removed with the knife. In exceptional cases they prove cancerous, as they usually are in man.

EPITHELIAL CANCER, OR EPITHELIOMA.

This sometimes occurs on the lips at the angle of the mouth and elsewhere in the horse. It begins as a small, wartlike tumor, which grows slowly at first, but finally bursts open, ulcerates, and extends laterally and deeply in the skin and other tissues, destroying them as it advances (rodent ulcer). It is made up of a fibrous framework and numerous round, ovoid, or cylindrical cavities, lined with masses of epithelial cells, which may be squeezed out as a fetid, caseous material. Early and thorough removal with the knife is the most successful treatment.

VEGETABLE PARASITES OF THE SKIN.

(Pl. XXXVIII, figs. 2, 3, 4.)

PARASITE: Trichophyton tonsurans. MALADY: Tinea tonsurans, or circinate ringworm.—This is especially common in young horses coming into training and work, in low-conditioned colts in winter and spring after confinement indoors, during molting, in lymphatic rather than nervous subjects, and at the same time in several animals that have herded together. The disease is common to man, and among the domestic animals to horse, ox, goat, dog, cat, and in rare instances to sheep and swine. Hence it is common to find animals of different species and their attendants suffering at once, the diseases having been propagated from one to the other.

Symptoms.—In the horse the symptoms are the formation of a circular, scurfy patch where the fungus has established itself, the hairs of the affected spot being erect, bristly, twisted, broken, or split up and dropping off. Later the spot first affected has become entirely bald, and a circular row of hairs around this are erect, bristly, broken, and split. These in turn are shed and a new row outside passes through the same process, so that the extension is made in more or less circular outline. The central bald spot, covered with a grayish scurf and surrounded by a circle of broken and split hairs, is characteristic. If the scurf and diseased hairs are treated with caustic-potash solution and put under the microscope, the natural cells of the cuticle and hair will be seen to have become transparent, while the groups of spherical cells and branching filaments of the fungus stand out prominently in the substance of both, dark and unchanged. The eruption usually appears on the back, loins, croup, chest, and head. It tends to spontaneous recovery in a month or two, leaving for a time a dappled coat from the spots of short, light-colored hair of the new growth.

The most effective way of reaching the parasite in the hair follicles is to extract the hairs individually, but in the horse the mere shaving of the affected part is usually enough. It may then be painted with tincture of iodin twice a day for two weeks. Germs about the stable may be covered up or destroyed by a whitewash of freshly burned quicklime, the harness, brushes, etc., may be washed with caustic soda, and then smeared with a solution of corrosive sublimate one-half dram and water 1 pint. The clothing may be boiled and dried.

PARASITE: Achorion schoenleini. MALADY: Favus, or honeycomb ringworm.—Megnin and Goyau, who describe this in the horse, say that it loses its characteristic honeycomb or cup-shaped appearance, and forms only a series of closely aggregated, dry, yellowish crusts the size of hemp seed on the trunk, shoulders, flanks, or thighs. They are accompanied by severe itching, especially at night. The cryptogam, formed of spherical cells with a few filaments only, grows in the hair follicles and on the cuticle, and thus a crust often forms around the root of a hair. Like the other cryptogams, their color, as seen under the microscope, is unaffected by acetic acid, alcohol, ether, or oil of turpentine, while the cells are turned bluish by iodin. For treatment, remove the hair and apply tincture of iodin or corrosive sublimate lotion, as advised under the last paragraph.

PARASITE: Microsporon furfur. MALADY: Parasitic pityriasis.—This attacks the horse's head where the harness presses, and leads to dropping of the hair, leaving bald patches covered with a branlike scurf, without any eruption, heat, tenderness, swelling, or rigidity of the skin. A lotion of carbolic acid 1 dram and water 2-1/2 ounces is usually applied to effect a cure.

ANIMAL PARASITES OF THE SKIN.[6]

ACARIASIS, OR MANGE.

This affection is due to the irritation of the skin caused by the presence of nearly microscopic acari, or mites. The disease varies, however, according to the species of acarus which infests the skin, so that we must treat of several different kinds of acariasis.

PARASITE: Sarcoptes scabiei equi. MALADY: Sarcoptic acariasis.—This is the special Sarcoptes of the horse, but under favorable conditions it can be transmitted to ass and mule, and even to man, and may live indefinitely on the human skin. The mite (Pl. XXXIX, fig. 1) is nearly microscopical, but may be detected with a magnifying lens among moving scurf taken from the infected skin. Like all Sarcoptes, it burrows little galleries in and beneath the scurf skin, where it hides and lays its eggs and where its young are hatched. It is therefore often difficult to find the parasite on the surface, unless the skin has been heated by a temporary exposure to the sun or in a warm room. The mite may be detected more readily by placing scrapings on black cardboard and warming, or better by macerating scabs or scrapings in a solution of caustic soda or potash and then examining them microscopically. Like other acari, this is wonderfully prolific, a new generation of fifteen individuals being possible every fifteen days, so that in three months the offspring of a single pair may produce generations aggregating 1,500,000 young. The Sarcoptes have less vitality than the nonburrowing acari, as they die in an hour when kept apart from the skin in dry air at a heat of 145 deg. F. They live 12 to 14 days apart from the skin in the damp air of a stable. On a piece of damp hide they lived till the twenty-fourth day, when they began to die, and all were dead on the twenty-eighth.

Symptoms.—The symptoms are an incessant, intolerable, and increasing itching of some part of the skin (head, mane, tail, back, etc.), the horse inclining himself toward the hand that scratches him, and moving his lips as if himself scratching. The hairs may be broken and rubbed off, but the part is never entirely bald, as in ringworm, and there may be papules or any kind of eruption or open sores from the energy of the scratching. Scabs of any thickness may form, but the special features are the intense itching and the presence of the acarus.

Treatment consists in the removal of the scabs by soapsuds, and, if necessary, a brush and the thorough application of tobacco 1-1/2 ounces and water 2 pints, prepared by boiling. This may be applied more than once, and should always be repeated after 15 days, to destroy the new brood that may have been hatched in the interval. All harness and stable utensils should be similarly treated; blankets and rubbers may be boiled, and the stalls should be covered with a whitewash of quicklime, containing one-fourth pound of chlorid of lime to the gallon.

When there are too many animals to treat by means of hand dressings, the lime-and-sulphur dip or the tobacco dip may be used and are very effective, though the cresol dips are fairly effective. These dips may be purchased and made up in the dilution called for on the container. The affected animals may be dipped when the number warrants it and facilities are available; otherwise the dips may be applied with a swab or a spray pump. Directions for constructing a dipping vat may be obtained from the United States Department of Agriculture on application. Any treatment used should be repeated in the course of 10 to 14 days. If the stables are not disinfected, animals should be removed after treatment and put in clean stables or on clean pasture for at least a month to allow the mites in the infested stables to die. Otherwise the disease may recur.

PARASITE: Psoroptes equi (Dermatocoptes equi, Dermatodectes equi). MALADY: Psoroptic acariasis.—Psoroptic mange is less common than sarcoptic mange in horses, and as the parasite (Pl. XXXIX, fig. 3) only bites the surface and lives among the crusts under the shelter of the hair, it is very easily discovered. It reproduces itself with equal rapidity and causes similar symptoms to those produced by the Sarcoptes. The same treatment will suffice and is more promptly effectual. The purifying of the stable must be more thorough, as the Psoroptes will survive twenty to thirty days in the moist atmosphere of a stable, and may even revive after six or eight weeks when subjected to moist warmth. Infested pastures will therefore prove dangerous to horses for that length of time, and, with rubbing posts, etc, should not be used.

PARASITE: Chorioptes equi (Symbiotes equi, Dermatophagus equi, Chorioptes spathiferus). MALADY: Foot mange.—The acarus (Pl. XXXIX, fig. 2) attacks the heels and lower parts of the legs, especially the hind ones, and may be present for years without extending upon the body. Like the Psoroptes; it lives on the surface, on the hairs, and among the scabs. It gives rise to great itching, stamping, rubbing of the one leg with the other, and the formation of papules, wounds, ulcerous sores, and scabs. The intense itching will always suggest this parasite, and the discovery of the acarus will identify the disease. The treatment is the same as for the Sarcoptes, but may be confined to the legs and the parts with which they come in contact.

PARASITE: Dermanyssus gallinae, or chicken acari. MALADY: Poultry acariasis.—This is a large-sized acarus, though usually miscalled "hen louse," and the disease "poultry lousiness." The mite (Pl. XXXIX, fig. 4) lives in droppings and in crevices of chicken houses, but temporarily passes on to the skin of man and of the horse and other quadrupeds, when occasion serves. It causes much irritation, with the eruption of papules or vesicles and the formation of sores and scabs. The examination of the skin is usually fruitless, as the attacks are mostly made at night and the effects only may be seen during the day. The proximity of hen manure swarming with the acari explains the trouble, and the removal of this and a white-washing with quicklime, with or without chlorid of lime, will prevent future attacks. The skin may still require bland ointments or lotions, as for congestion.

PARASITE: Larva of a Trombidium, Leptus americanus, or harvest bug, misnamed jigger (chigoe). MALADY: Autumn mange.—This parasite is a brick-red acarus, visible to the naked eye on a dark ground, and living on green vegetation in many localities. It attacks man, and the horse, ox, dog, etc., burrowing under the skin and giving rise to small papules and intolerable irritation. This continues for two or three days only from a single invasion, but will last until cold weather sets in if there is a fresh invasion daily. Horses at pasture suffer mainly on the lower part of the face. If kept indoors the disease will disappear, or if left at pasture a weak tar water or solution of tobacco may be applied to the face.



TICKS.

The wood ticks are familiar to inhabitants of uncultivated lands, and prove troublesome parasites to man and beast alike. The tick lives on bushes, and attaches itself to the mammal only to secure a feast of blood, for when gorged it drops off to sleep off its debauch on the soil. The tick produces great irritation by boring into the skin with its armed proboscis. If pulled out, the head and thorax are often left in the skin. They may be covered with oil to shut out the air from their breathing pores, or by touching them with a hot penknife they will be impelled to let go their hold.

GRUBS IN SKIN.

PARASITE: Hypoderma lineata. MALADY: Larvae (grubs) under the skin.—The larvae of a fly (probably Hypoderma lineata, whose larvae in the skin of cattle are commonly known as "warbles") are occasionally found in little sacs beneath the skin of horses. The mature larva escapes in early summer and develops into a fly. In districts where they exist the grubs should be pressed out of the skin in the course of the winter and destroyed.

LARVAE (GRUBS) ON THE SKIN, OR FLYBLOW.

The following flies, among others, deposit their eggs on open sores or on wet, filthy parts of the skin, where their larvae or grubs give rise to serious trouble: Lucilia caesar (bluebottle), Cochliomyia macellaria (screwworm fly), Musca vomitoria (meat fly), and Sarcophaga carnaria (flesh fly). To prevent their attacks, wet, filthy hair should be removed and wounds kept clean and rendered antiseptic by a lotion of carbolic acid 1 part, water 50 parts, or by a mixture of 1 ounce oil of tar in 20 ounces sweet oil, or by some other antiseptic. If the grubs are already present they should be picked off and one of these dressings freely applied.

FLIES.

A number of flies attack horses and suck their blood, producing great annoyance and in some instances death. These insects not only suck the blood, but also often instill an acid poison into the skin, and in exceptional cases transfer infectious germs from animal to animal by inoculation.

Various devices are resorted to to prevent the attacks, as to sponge the skin with a decoction of walnut or elder leaves, of tobacco, to dust with Persian insect powder, to keep a light blanket or fly net on the horse, to close doors and windows with fine screens and destroy by pyrethrum any flies that have gained admission, to remove all manure heaps that would prove breeding places for flies, to keep the stalls clean, deodorize by gypsum, and to spread in them trays of dry chlorid of lime. For the poisoned bites apply ammonia, or a solution of 1 part of carbolic acid in 20 parts of sweet oil or glycerin, or one-fourth ounce bicarbonate of soda and 1 dram of carbolic acid in a quart of water may be used.

A large number of fly repellents have been recommended, but most of them must be applied daily in order to maintain the protective effect. Among the things used are carbolic solutions, pine tar, oil of tar, fish oil, laurel oil, oil of citronella, oil of sassafras, oil of camphor, and cod-liver oil. These things must be used judiciously or they will result in poisoning or removal of the hair from the animal in some instances. Ten per cent oil of tar in Beaumont oil or in cottonseed oil was found to be safe and efficacious by Graybill.

The use of the fly-maggot trap noted under stomach worms of the horse, and of the various forms of the Hodge flytrap, is recommended.

FLEAS.

The flea of man and those of poultry, when numerous, will bite the horse and give rise to rounded swellings on the skin. To dispose of them it is needful to clear the surroundings of the grublike larvae as well as to treat the victim. The soil may be sprinkled with quicklime, carbolic acid, coal tar, or petroleum; the stalls may be deluged with boiling water and afterwards painted with oil of turpentine and littered with fresh pine sawdust, and all blankets should be boiled. The skin may be sponged with a solution of 1 part carbolic acid in 50 parts of water. Other animals should be kept free from fleas or kept away from the vicinity of the stable.

The chigoe (Pulex penetrans) of the Gulf coast is still more injurious, because it burrows under the surface and deposits its eggs to be hatched out slowly with much irritation. The tumor formed by it should be laid-open and the parasite extracted. If it bursts so that its eggs escape into the wound, they may be destroyed by introducing chloroform into the wound.

LICE, OR PEDICULI.

Two kinds of lice attack the horse, one of which is furnished with narrow head and a proboscis for perforating the skin and sucking the blood, and the other—the broad-headed kind—with strong mandibles, by which it bites the skin only. The poor condition, itching, and loss of hair should lead to suspicion, and a close examination will detect the lice. They may be destroyed by rubbing the victim with sulphur ointment, or with sulphuret of potassium 4 ounces, water 1 gallon, or with tar water, or the skin may be sponged with benzine. The application should be repeated a week later to destroy all lice hatched from the nits in the interval. Buildings, clothes, etc., should be treated as for fleas.

STINGS OF BEES, WASPS, AND HORNETS.

These are much more irritating than the bites of flies, partly because the barbed sting is left in the wound and partly because of the quantity and quality of the venom. When a swarm attacks an animal the result may prove fatal.

Treatment consists in the application of wet clay, or of a lotion of soda or ammonia, or of carbolic acid, or permanganate of potash, 2 grains to the ounce; or of sugar of lead 2 drams, laudanum 1 ounce, and water 1 pint. The embedded stings should be extracted with fine forceps or even with the finger nails.

TARANTULA AND SCORPION.

The bite of the first and the sting of the second are poisonous, and may be treated like other insect venom, by carbolated glycerin, or a strong solution of ammonia, or permanganate of potash.

SNAKE BITES.

These are marked by the double incision caused by the two fangs, by the excessive doughy (dark red) swelling around the wounds, and in bad cases by the general symptoms of giddiness, weakness, and prostration. They are best treated by enormous doses of alcohol, whisky, or brandy, or by aqua ammonia very largely diluted in water, the object being to sustain life until the poison shall have spent its power. As local treatment, if the wound is in a limb, the latter may have a handkerchief or cord tied around it above the injury and drawn tight by a stick twisted into it. In this way absorption may be checked until the poison can be destroyed by the application, of a hot iron or a piece of nitrate of silver or other caustic. A poultice of tobacco leaves is a favorite remedy, and may be used to soothe the sore after cauterization.

A treatment which has been highly recommended consists in prompt and vigorous scarification at the site of puncture and rubbing crystals of potassium permanganate into the wound.

BURNS AND SCALDS.

These subjects are discussed in the following chapter.

WOUNDS OF THE SKIN.

Wounds of the skin are fully discussed in the next chapter.

FOOTNOTES:

[3] An outbreak of quittor near Cheyenne, Wyo., which came under the author's observation, was caused by the mud through which the horses had to wade to reach the watering troughs. These troughs were furnished with water by windmills, and the mudholes were caused by the waste water. More than 50 cases developed inside of two months, or during September and October. In these 50 cases all forms of the disease and all possible complications were presented. During the rainy season at Leadville, Colo., outbreaks of quittor are common, and the disease is so virulent that it has long been known as the "Leadville foot rot." The soil being rich in mineral matters is no doubt the cause of the outbreaks. In the city of Montreal quittor is said to be very common in the early springtime, when the streets are muddy from the melting snow and ice.

[4] Descazeaux has shown that the worms found in these summer sores are probably larval forms of the stomach worms of the horse, Habronema megastoma, H. microstoma, and H. muscae. Ransom has shown that the larval stage of H. muscae develops in the common housefly, the fly becoming infested as a maggot in horse manure. Infestation with the adult worms in the stomach of the horse (Pl. V, fig. 4) may take place through the ingestion of such infested flies, or by the escape of the larva from the proboscis of the fly as it feeds on the moist lips of the horse. In view of this it may be surmised that summer sores may arise as the result of flies so infested feeding on the moisture on the skin of the horse. In some forms of summer sores along the abdomen there are found immature stages of Habronema which apparently have just escaped from the egg and which are younger than some of the stages found in the fly. In this case it is surmised that these embryos from the manure enter the soiled skin of the horse, as it lies down on dirty bedding and manure, and develop in the skin as they would ordinarily in the fly. Descazeaux calls these summer sores cutaneous habronemiasis.

Preventive measures consist in the removal of the adult worms from the stomach of the horse by the use of anthelmintics, the destruction of the embryos in the manure, fly-control measures, and the use of clean bedding.—M. C. HALL.

[5] Descazeaux recommends the application and injection of 2 to 3 per cent trypanblue, though he states that the only truly efficacious treatment is the early and complete ablation of the invaded tissue.—M. C. H.

[6] Revised by M. C. Hall.



WOUNDS AND THEIR TREATMENT.

By CH. B. MICHENER, V. S.

[Revised by John R. Mohler, V. M. D., A. M.]

DESCRIPTION OF WOUNDS.

A wound is an injury to any part of the body involving a solution of continuity or disruption of the affected parts and is caused by violence, with or without laceration of the skin. In accordance with this definition we have the following varieties of wounds: Incised, punctured, contused, lacerated, gunshot, and poisoned. They may further be classified as superficial, deep, or penetrating, and also as unclean, if hair, dirt, or splinters of wood are present; as infected when contaminated with germs, and as aseptic if the wound does not contain germs.

An incised wound is a simple cut made with a sharp body, like a knife, producing merely a division of the tissues. The duller the body the more force is required, the more tissues destroyed, and a greater time will be required for healing. In a cut wound the edges are even and definite, while those of a lacerated wound are irregular and torn. Three conditions are present as a result of an incised wound: (1) Pain, (2) hemorrhage, (3) gaping of the wound. The first pain is due to the crushing and tearing of the nerve fibers. In using a sharp knife and by cutting quickly, the animal suffers less pain and healing occurs more rapidly. The secondary pain is usually due to the action of the air and inflammatory processes. When air is kept from the wound pain ceases soon after the lesion is produced. Hemorrhage is absent only in wounds of nonvascular tissues, as the cornea of the eye, the cartilage of joints, and other similar structures. Bleeding may be from the arteries, veins, or capillaries. In the last form of bleeding the blood oozes from the part in drops. Hemorrhage from the veins is dark red and issues in a steady stream without spurting. In arterial bleeding the blood is bright red and spurts with each heart beat. This latter variety of hemorrhage is the most dangerous, and should be stopped at once before attempting any further treatment. Bleeding from small veins and capillaries ceases in a short time spontaneously, while larger vessels, especially arteries, require some form of treatment to cause complete stoppage of the hemorrhage.

HEMOSTASIA.

By this term is meant the checking of the flow of blood. It may be accomplished by several methods, such as compress bandages, torsion, hot iron, and ligatures. The heat from a hot iron will cause the immediate clotting of the blood in the vessels, and this clot is further supported by the production of a scab, or crust, over the portion seared. The iron should be at a red heat. If at a white heat, the tissue is charred, which makes it brittle and the bleeding is liable to be renewed. If the iron is at a black heat, the tissue will stick to the iron and will pull away from the surface of the wound. Cold water and ice bags quickly stop capillary bleeding, while hot water is preferable in more excessive hemorrhages. Some drugs, called styptics, possess the power of contracting the walls of blood vessels and also of clotting the blood. A solution of the chlorid of iron placed on a wound alone or by means of cotton drenched in the liquid produces a rapid and hard clot. Tannic acid, alum, acetic acid, alcohol, and oil of turpentine are all more or less active in this respect. To check bleeding from large vessels compression may be adopted. When it is rapid and dangerous and from an artery, the fingers may be used for pressing between the wound and the heart (digital compression), but if from a vein, the pressure should be exerted on the other side of the wound. Tourniquet may also be used by passing a strap around the part and tightening after placing a pad over the hemorrhage. The rubber ligature has now replaced the tourniquet and is bound tightly around the limb to arrest the bleeding. Tampons, such as cotton, tow, or oakum, may be packed tightly in the wound and then sewed up. After remaining there for twenty-four or forty-eight hours they are removed. Bleeding may sometimes be easily checked by passing a pin under the vessel and by taking a horsehair and forming a figure 8 by running it above and below the pin, thus causing pressure on the vessel. Torsion is the twisting of the blood vessel until the walls come together and form a barrier to the flow of blood. It may be accomplished by the fingers, forceps, or by running a pin through the vessel, turning it several times, and then running the point into the tissue to keep it in a fixed position.

Ligation is the third method for stopping a hemorrhage. The blood vessel should be seized with the artery forceps, a clean thread of silk passed around it, and tied about one-half inch from its end. The silk should be sterilized by placing it in an antiseptic solution so as not to impede the healing process or cause blood poisoning or lockjaw, which often follows the ligation of a vein with unsterilized material. Sometimes it will be impossible to reach the bleeding vessel, so it is necessary to pass the ligature around a mass of tissue which includes the blood vessel. Ligation is the most useful method of arresting hemorrhage, since it disturbs healing least and gives the greatest security against secondary hemorrhage.

SUTURES.

After the bleeding has been controlled and all foreign bodies removed from the wound, the gaping of the wound is noticeable. It is caused by the contraction of the muscles and elastic fibers, and its degree depends on the extent, direction, and nature of the cut. This gaping will hinder the healing process so that it must be overcome by bringing the edges together by some sort of sutures or pins or by a bandage applied from below upward. As suture material, ordinary cotton thread is good, if well sterilized, as are also horsehair, catgut, silk, and various kinds of wire. If the suture is made too tight the subsequent swelling may cause the stitch to tear out. In order to make a firm suture the depth of the stitch should be the same as the distance the stitch is from the edge of the wound. The deeper the suture the more tissue is embraced and the fewer the number of stitches required. In tying a suture the square or reef knot should be used. Closure of wounds by means of adhesive plaster, collodion, and metal clamps is not practiced to any great extent in veterinary practice.

PROCESS OF HEALING.

In those cases where perfect stoppage of bleeding, perfect coaptation of the edges of the wound, and perfect cleanliness are obtained, healing occurs within three days, without the formation of granulations, pus, or proud flesh, by what is termed first intention. If wounds do not heal in this manner they will gap somewhat and become warm and painful. Healing then occurs by granulation or suppuration, which is termed healing by second intention. The sides of the wound become covered with granulation tissue which may fill the wound and sometimes overlap the lips, forming a fungoid growth called proud flesh. Under favorable conditions the edges of the wound appear to grow together by the end of the first week, and the whole surface gradually becomes dry, and finally covered with pigmented skin, when the wound is healed. The cause of pus formation in wounds is usually the presence of germs. For this reason the utmost care should be adopted to keep clean wounds aseptic, or free from germs, and to make unclean wounds antiseptic by using antiseptic fluids to kill the microbes present in the wound. The less the injurious action of this fluid on the wound and the greater its power to kill germs, the more valuable it becomes. All antiseptics are not equally destructive, and some germs are more susceptible to one antiseptic than to another. The most important are (1) bichlorid of mercury, which is to be preferred on horses. It becomes weakened in its action if placed in a wooden pail or on an oily or greasy surface. It is used in the strength of 1 part of bichlorid to 1,000 to 5,000 parts of water, according to the delicacy of the tissue to which it is applied. (2) Carbolic acid in from 2 to 5 per cent solution is used on infected wounds and for cleaning instruments, dressings, and sponges. It unites well with oil and is preferred to the bichlorid on a greasy surface. A 5 per cent solution in oil is often used under the name of carbolized oil. (3) Aluminum acetate is an efficient and cheap antiseptic, and is composed of 1 part alum and 5 parts acetate of lead, mixed in 20 parts of water. (4) Boric acid is good, in a 2 to 4 per cent solution, to cleanse wounds and wash eyes. Compound cresol may be used in a 1 to 3 per cent solution in water. Iodoform is one of the most used of the antiseptics, and it also acts as an anodyne, stimulates granulation, and checks wound secretion. A very efficacious and inexpensive powder is made by taking 5 parts of iodoform and 95 parts of sugar, making what is called iodoform sugar. Tannic acid is a useful drug in the treatment of wounds, as it arrests hemorrhage, checks secretion, and favors the formation of a scab. A mixture of 1 part tannic acid and 3 parts iodoform is good in suppurating wounds. Iodol, white sugar, ground and roasted coffee, and powdered charcoal are all used as protectives and absorbents on suppurating surfaces. More depends on the care and the method of application of the drug than on the drug itself. On aseptic wounds use only those antiseptics that do not irritate the tissue. If care is used in the application of the antiseptic, corrosive sublimate or carbolic acid is to be recommended. In order to keep air from the wound and to absorb all wound secretions rapidly, a dressing should be applied. If the wound is aseptic, the dressing should be likewise, such as cotton gauze, sterile cotton, oakum, or tow. This dressing should be applied with uniform pressure at all times and secured by a bandage. Allow it to remain for a week or ten days if the wound is aseptic or if the dressing does not become loose or misplaced or become drenched with secretions from the wound, or if pain, fever, or loss of appetite does not develop. The dressing should then be removed, the wound treated antiseptically, and a sterilized dressing applied.

HEALING UNDER A SCAB.

This often occurs in small superficial wounds that have been kept aseptic. In order that a scab may form, the wound must not gap, secrete freely, or become infected with germs. The formation of scab is favored by astringents and styptics, such as tannic acid, iodoform, and 5 per cent solution of zinc chlorid. In case of fistulous withers, open joints, or other large, hollow wounds that can not be dressed, antisepsis may be obtained by warm-water irrigation with or without an antiseptic fluid. It should continue day and night, and never be interrupted for more than eight hours, for germs will then have gained headway and will be difficult to remove. Four or five days of irrigation will be sufficient, for granulations will then have formed and pus will remain on the outside if it forms. For permanent irrigation the stream should be very small, or drop by drop, but should play over the entire surface of the wound. It is always better to heal an infected wound under a scab, or treat it as an open wound, than it is to suture it, thus favoring the growth of the inclosed germs and retarding ultimate healing. In the latter case pus may develop in the wound, form pockets by sinking into the tissues, and cause various complications. The pockets should be well drained, either through incisions at the bottom or by drainage tubes or setons. They should then be frequently syringed out or continuously irrigated. In case proud flesh appears it should be kept down either by pressure or by caustics, as powdered bluestone, silver nitrate, chlorid of antimony, or by astringents, such as burnt alum. If they prove resistant to this treatment they may be removed by scissors, the knife, or by searing with the hot iron. The following rules for the treatment of wounds should be followed: (1) See that the wound is clean, removing all foreign bodies. (2) For this purpose use a clean finger rather than a probe. (3) All hemorrhage should be arrested before closing the wound. (4) Antiseptics should only be used if you suspect the wound to be infected. (5) When pus is present treat without closing the wound. (6) This may be accomplished by drainage tubes, absorbent dressings, setons, or continuous irrigations. (7) Protect the wound against infection while healing.

LACERATED AND CONTUSED WOUNDS.

Lacerated and contused wounds may be described together although there is, of course, this difference, that in contused wounds there is no break or laceration of the skin. Lacerated wounds, however, are, as a rule, also contused—the surrounding tissues are bruised to a greater or lesser extent. While at first sight such wounds may not appear to be as serious as incised wounds, they are commonly very much more so. Lacerations and contusions, when extensive, are always to be regarded as dangerous. Many horses die from septic infection or mortification as a result of these injuries. We find in severe contusions an infiltration of blood into the surrounding tissues: disorganization and mortification follow, and involve often the deeper seated structures. Abscesses, single or multiple, may also result and call for special treatment.

In wounds that are lacerated the amount of hemorrhage is mostly inconsiderable; even very large blood vessels may be torn apart without inducing a fatal result. The edges of the wound are ragged and uneven. These wounds are produced by barbed wire or some blunt object, as when a horse runs against fences, board piles, the corners of buildings, or when he is struck by the pole or shafts of another team, falling on rough, irregular stones, etc.

Contused wounds are caused by blunt instruments moving with sufficient velocity to bruise and crush the tissues, as kicks, running against objects, or falling on large, hard masses.

Treatment.—In lacerated wounds great care must at first be exercised in examining or probing to the very bottom of the rent or tear, to see whether any foreign body is present. Very often splinters of wood or bits of stone or dirt are thus lodged, and unless removed prevent the wound from healing; or if it should heal, the wound soon opens again, discharging a thin, gluey matter that is characteristic of the presence of some object in the part. After a thorough exploration these wounds are to be carefully and patiently fomented with warm water, to which has been added carbolic acid in the proportion of 1 part to 100 of water. Rarely, if ever, are stitches to be inserted in lacerated wounds. The surrounding tissues and skin are so weakened in vitality and structure by the contusions that stitches will not hold; they only irritate the parts. It is better to endeavor to obtain coaptation by means of bandages, plasters, or collodion. One essential in the treatment of lacerated wounds is to provide a free exit for the pus. If the orifice of the wound is too high, or if pus is found to be burrowing in the tissues beneath the opening, we must then make a counter opening as low as possible. This will admit of the wound being thoroughly washed out, at first with warm water, and afterwards injected with some mild astringent and antiseptic wash, as chlorid of zinc, 1 dram to a pint of water. A dependent opening must be maintained until the wound ceases to discharge. Repeated hot fomentations over the region of lacerated wounds afford much relief and should be persisted in.

BRUISES.

Bruises are nothing but contused wounds where the skin has not been ruptured. There is often considerable solution of continuity of the parts under the skin, subcutaneous hemorrhage, etc., which may result in local death (mortification) and slough of the bruised parts. If the bruise or contusion is not so severe, many cases are quickly cured by constant fomentation with hot water for from two to four hours. The water should be allowed about this time to become cool gradually and then cold. Cold fomentation must then be kept up for another hour or two. The parts should be thoroughly and quickly dried and bathed freely with camphor 1 ounce, sweet oil 8 ounces, or with equal parts of lead water and laudanum. A dry, light bandage should then be applied, the horse allowed to rest, and if necessary the treatment may be repeated each day for two or three days. If, however, the wound is so severe that sloughing must ensue, we should encourage it by poultices made of linseed meal, wheat bran, turnips, onions, bread and milk, or hops. Charcoal is to be sprinkled over the surface of the poultice when the wound is bad smelling. After the slough has fallen off the wound is to be dressed with warm washes of carbolic acid, chlorid of zinc, permanganate of potash, or other antiseptic. If granulating (filling up) too fast, use burnt alum or air-slaked lime. Besides this local treatment, we find that the constitutional symptoms of fever and inflammation call for measures to prevent or control them. This is best done by placing the injured animal on soft or green feed. A physic of Barbados aloes, 1 ounce, should be given as soon as possible after the accident. Sedatives, such as tincture of aconite root, 15 drops, three times a day, or ounce doses of saltpeter every four hours, may also be administered. When the symptoms of fever are abated, and if the discharges from the wound are abundant, the strength of the patient must be supported by good feed and tonics. One of the best tonics is as follows: Powdered sulphate of iron, powdered gentian, and powdered ginger, of each 4 ounces. Mix thoroughly and give a heaping tablespoonful twice a day, on the feed or as a drench.

PUNCTURED WOUNDS.

Punctured wounds are produced by the penetration of a sharp or blunt-pointed substance, such as a thorn, fork, nail, etc., and the orifice of these wounds is always small in proportion to their depth. In veterinary practice punctured wounds are much more common than the others. They involve the feet most frequently, next the legs, and often the head and face from nails protruding through the stalls and trough. They are not only the most frequent, but they are also the most serious, owing to the difficulty of obtaining thorough disinfection. Another circumstance rendering them so is the lack of attention that they at first receive. The external wound is so small that but little or no importance is attached to it, yet in a short time swelling, pain, and acute inflammation, often of a serious character, are manifested.

Considering the most common of the punctured wounds, we must give precedence to those of the feet. Horses worked in cities, about iron works, around building places, etc., are most likely to receive "nails in the feet." The animal treads upon nails, pieces of iron or screws, forcing them into the soles of the feet. If the nail, or whatever it is that has punctured the foot, is fast in some large or heavy body, and is withdrawn as the horse lifts his foot, lameness may last for only a few steps; but unless properly attended to at once he will be found in a day or two to be very lame in the injured member. If the foreign body remains in the foot, he gradually grows worse from the time of puncture until the cause is discovered and removed. If, when shoeing, a nail is driven into the "quick" (sensitive laminae) and allowed to remain, the horse gradually evinces more pain from day to day; but if the nail has at once been removed by the smith, lameness does not, as a rule, show itself for some days; or, if the nail is simply driven "too close," not actually pricking the horse, he may not show any lameness for a week or even much longer. At this point it is due to the blacksmith to say that, considering how thin the walls of some feet are, the uneasiness of many horses while shoeing, the ease with which a nail is diverted from its course by striking an old piece of nail left in the wall, or from the nail itself splitting, the wonder is not that so many horses are pricked or nails driven "too close," but rather that many more are not so injured. It is not, by any means, always carelessness or ignorance on the part of the smith that is to account for this accident. Bad and careless shoers we do meet with, but let us be honest and say that the rarity of these accidents points rather to the general care and attention given by these much-abused mechanics.

From the construction of the horse's foot (being incased in an impermeable, horny box), and from the elasticity of the horn closing the orifice, punctured wounds of the feet are almost always productive of lameness. Inflammation results, and as there is no relief afforded by swelling and no escape for the product of inflammation, this matter must and does burrow between the sole or wall and the sensitive parts within it until it generally opens "between hair and hoof." We can thus see why pain is so much more severe, why tetanus (lockjaw) more frequently follows wounds of the feet, and why, from the extensive, or at times complete, separation and "casting" of the hoof, these wounds must always be regarded with grave apprehension.

Symptoms and treatment.—A practice which, if never deviated from—that of picking up each foot, cleaning the sole, and thoroughly examining the foot each and every time the horse comes into the stable—will enable us to reduce to the minimum the serious consequences of punctured wounds of the feet. If the wound has resulted from pricking, lameness follows soon after shoeing; if from the nails being driven too close, it usually appears from four to five days or a week afterwards. We should always inquire as to the time of shoeing, examine the shoe carefully, and see whether it has been partially pulled and the horse has stepped back upon some of the nails or the clip. The pain from these wounds is lancinating; the horse is seen to raise and lower the limb or hold it from the ground altogether; often he points the foot, flexes the leg, and knuckles at the fetlock. Swelling of the fetlock and back tendons is also frequently seen and is liable to mislead us. The foot must be carefully examined, and this can not be properly done without removing the shoe. The nails should be drawn separately and carefully examined. If there is no escape of pus from the nail holes, or if the nails themselves are not moist, we must continue our examination of the foot by carefully pinching or tapping it at all parts. With a little practice we can detect the spot where pain is the greatest or discover the delicate line or scar left at the point of entrance of the foreign body. The entire sole is then to be thinned, after which we are carefully to cut down upon the point where pain is greatest upon pressure, and, finally, through the sole at this spot. When the matter has escaped, the sole, so far as it was undermined by pus, is to be removed. The foot must now be poulticed for one or two days and afterwards dressed with a compress of oakum saturated with carbolic-acid solution or other antiseptic dressing.

If we discover a nail or other object in the foot, the principal direction, after having removed the offending body, is to cut away the sole, in a funnel shape, down to the sensitive parts beneath. This is imperative, and if a good free opening has been made and is maintained for a few days, and hot fomentations and antiseptic dressings applied, the cure is mostly easy, simple, quick, and permanent. The horse should be shod with a leather sole under the shoe, first of all applying tar and oakum to prevent any dirt from entering the wound. In some instances nails may puncture the flexor tendons, the coffin bone, or enter the coffin joint. Such injuries are always serious, their recovery slow and tedious, and the treatment so varied and difficult that the services of a veterinarian will be necessary.

PUNCTURED WOUNDS OF JOINTS, OR OPEN JOINTS.

These wounds are more or less frequent. They are always serious, and often result in anchylosis (stiffening) of the joint or the death of the animal. The joints mostly punctured are the hock, fetlock, or knee, though other joints may, of course, suffer this injury. As the symptoms and treatment are much the same for all, only the accident as it occurs in the hock joint will be described. Probably the most common mode of injury is from the stab of a fork, but it may result from the kick of another horse that is newly shod, or in many other ways. At first the horse evinces but slight pain or lameness. The owner discovers a small wound scarcely larger than a pea, and pays but little attention to it. In a few days, however, the pain and lameness become excessive; the horse can no longer bear any weight upon the injured leg; the joint is very much swollen and painful upon pressure; there are well-marked symptoms of constitutional disturbance—quick pulse, hurried breathing, high temperature, 103 deg. to 106 deg. F., the appetite is lost, thirst is present, the horse reeks with sweat, and his anxious countenance shows the pain he suffers. He may lie down, though mostly he persists in standing, and the opposite limb becomes greatly swollen from bearing the entire weight and strain for so long a time. The wound, which at first appeared so insignificant, is now constantly discharging a thin, whitish or yellowish fluid—joint oil or water, which becomes coagulated about the mouth of the wound and adheres to the part in clots like jelly, or resembling somewhat the white of an egg. Not infrequently the joint opens at different places, discharging at first a thin, bloody fluid that soon assumes the character above described.

Treatment of these wounds is most difficult and unsatisfactory. We can do much to prevent this array of symptoms if the case is seen early—within the first 24 or 48 hours after the injury; but when inflammation of the joint is once fairly established the case becomes one of grave tendencies. Whenever a punctured wound of a joint is noticed, even though apparently of but small moment, we should apply without the least delay a strong cantharides blister over the entire joint, being even careful to fill the orifice of the wound with the blistering ointment. This treatment is almost always effectual. It operates to perform a cure in two ways—first, the swelling of the skin and tissues underneath it completely closes the wound and prevents the ingress of air; second, by the superficial inflammation established it acts to check and abate all deep-seated inflammation. In the great majority of instances, if pursued soon after the accident, this treatment performs a cure in about one week; but should the changes described as occurring later in the joint have already taken place, we must then treat by cooling lotions and the application to the wound of chlorid of zinc, 10 grains to the ounce of water, or a paste made of flour and alum. A bandage is to hold these applications in place, which is only to be removed when swelling of the leg or increasing febrile symptoms demand it. In the treatment of open joints our chief aim must be to close the orifice as soon as possible. For this reason repeated probing or even injections are contraindicated. The only probing of an open joint that is to be sanctioned is on our first visit, when we should carefully examine the wound for foreign bodies or dirt, and after removing them the probe must not again be used. The medicines used to coagulate the synovial discharge are best simply applied to the surface of the wound, on pledgets of tow, and held in place by bandages. Internal treatment is also indicated in those cases of open joints in which the suffering is great. At first we should administer a light physic and follow this up with sedatives and anodynes, as directed for contused wounds. Later, however, we should give quinin or salicylic acid in 1-dram doses two or three times a day.

WOUNDS OF THE TENDON SHEATHS.

Wounds of tendon sheaths are similar to open joints in that there is an escape of synovial fluid, "sinew water." Where the tendons are simply punctured by a thorn, nail, or fork, we must, after a thorough exploration of the wound for any remaining foreign substance, treat with the flour-and-alum paste, bandages, etc., as for open joint. Should the skin and tendons be divided the case is even more serious and is often incurable. There is always a large bed of granulations (proud flesh) at the seat of injury, and a thickening more or less pronounced remains. When the back tendons of the leg are severed we should apply at once a high-heel shoe (which is to be gradually lowered as healing advances) and bandage firmly with a compress moistened with a 10-grain chlorid of zinc solution. When proud flesh appears it is best kept under control by repeated applications of a red-hot iron. Mares that are valuable as brood animals and stock horses should always be treated for this injury, as, even though blemished, their value is not seriously impaired. If the subject is old and comparatively valueless, the length of time required and the expense of treatment will cause us to hesitate in attempting a cure.

GUNSHOT WOUNDS.

These wounds vary in size and character, depending on the size and quality of the projectile and also the tissue injured. They are so seldom met with in our animals that an extended reference to them seems unnecessary. If a wound has been made by a bullet a careful examination should be made to ascertain whether the ball has passed through or out of the body. If it has not we must then probe for it, and if it can be located it is to be cut out when practicable to do so. Oftentimes a ball may be so lodged that it can not be removed, and it then may become encysted and remain for years without giving rise to any inconvenience. It is often difficult to locate a bullet, as it is very readily deflected by resistances met with after entering the body.

The entering wound is the size of the projectile, the edges are inverted and often scorched. The wound produced in case of the bullet's exit is larger than the projectile, the edges are turned out and ragged. A bullet heated by the friction of the barrel or air often softens and becomes flattened on striking a bone or other tissue. Modern bullets that have an outer steel layer may pass through bone without splintering it. Lead bullets may split, producing two exit wounds. Spent bullets may only produce a bruise. Should bones be struck by a ball they are sometimes shattered and splintered to such an extent as to warrant us in having the animal destroyed. A gunshot wound, when irreparable injury has not been done, is to be treated the same as punctured wounds, i. e., stop the hemorrhage, remove the foreign body if possible, and apply hot fomentations or poultices to the wound until suppuration is fairly established. Anti-septic and disinfectant injections may then be used. Should pus accumulate in the tissues, openings must be made at the most depending parts for its escape. Wounds from shotguns fired close to the animals are serious. They are virtually lacerated and contused wounds. Remove all the shot possible from the wound and treat as directed for contusions. When small shot strike the horse from a distance they stick in the skin or only go through it. The shot grains must be picked out, but as a rule this "peppering" of the skin amounts to but little.

POISONED WOUNDS.

These injuries are the result of bites of snakes, rabid dogs, stings of bees, wasps, etc. A single sting is not dangerous, but an animal is often stung by a swarm of insects, when the chief danger occurs from the swelling produced. If stung about the head, the nostrils may be closed as a result of the swelling, causing labored breathing and possibly asphyxiation. Intoxication may be produced by the absorption of this poison and is manifested by staggering gait, spreading of the legs, paralysis of the muscles, difficult respiration, and a rise of temperature. Death may follow in five to ten hours.

Treatment.—Douse animal with cold water and apply any alkaline liquid, such as soapsuds, bicarbonate of soda, or weak solution of ammonia. Internally give alcohol, ether, or camphor to strengthen the heart. In case of bites by rattlesnakes, moccasin, or other poisonous snakes, a painful swelling occurs about the bitten part, which is followed by labored breathing, weakness, retching, fever, and death from collapse. The animal usually recovers if it can be kept alive over the third day. In treating the animal, a tight ligature should be passed about the part above the wound to keep the poison from entering the general circulation. Wash out the wound thoroughly with antiseptics and then apply a caustic, such as silver nitrate, or burn with a hot instrument. A subcutaneous injection of one-fourth dram of 1 per cent solution of chromic acid above the wound is also beneficial. Cold water may be applied to the wound to combat the inflammation. Bites of rabid dogs produce an infected wound, and the virus of rabies introduced in this manner should be removed or destroyed in the wound. Therefore produce considerable bleeding by incising the wound, wash out thoroughly with 10 per cent solution of zinc chlorid, and then apply caustics or the actual cautery.

HARNESS GALLS (SITFASTS).

Wounds or abrasions of the skin are frequently caused by ill-fitting harness or saddles. When a horse has been resting from steady work for some time, particularly after being idle in a stable on a scanty allowance of grain, as in winter, he is soft and tender and sweats easily when put to work again. In this condition he is liable to sweat and chafe under the harness, especially if it is hard and poorly fitted. This chafing is likely to cause abrasions of the skin, and thus pave the way for an abscess or for a chronic blemish, unless attended to very promptly. Besides causing the animal considerable pain, chafing, if long continued, leads to the formation of a callosity. This may be superficial, involving only the skin, or it may be deep-seated, involving the subcutaneous fibrous tissue and sometimes the muscle and even the bone. This causes a dry slough to form, which is both inconvenient and unsightly. Sloughs of this kind are commonly called "sitfasts" and, while they occur in other places, are most frequently found under the saddle. (See also p. 475.)

Treatment.—Abrasions are best prevented by bringing the animal gradually into working shape after it has had a prolonged rest, in order that the muscles may be hard and the skin tough. The harness should be well fitted, neither too large nor too small, and it should be cleaned and oiled to remove all dirt and to make it soft and pliable. Saddles should be properly fitted so as to prevent direct pressure on the spine, and the saddle blankets should be clean and dry. Parts of the horse where chafing is likely to occur, as on the back under the saddle, should be cleaned and brushed free of dirt.

The remedies for simple harness galls are numerous. Among them may be mentioned alcohol, 1 pint, in which are well shaken the whites of two eggs; a solution of nitrate of silver, 10 grains to the ounce of water; sugar of lead or sulphate of zinc, 20 grains to an ounce of water; carbolic acid, 1 part in 15 parts of glycerin, and so on almost without end. Any simple astringent wash or powder will effect a cure, provided the sores are not irritated by friction.

If a sitfast has developed, the dead hornlike slough must be carefully dissected out and the wound treated carefully with antiseptics. During treatment it is always best to allow the animal to rest, but if this is inconvenient care should be taken to prevent injury to the abraded or wounded surface by padding the harness so that chafing can not occur.

BURNS AND SCALDS.

These wounds of domestic animals are fortunately of rare occurrence; however, when they do occur, if at all extensive, they prove to be quite troublesome and in many cases are fatal. According to the severity of the burn we distinguish three degrees: First degree, where there is a simple reddening of the skin; second degree, where there is a formation of vesicles, or blisters; third degree, where there is a complete destruction of vitality of the tissues, such as would occur in charring from direct contact with flames or from escaping steam. Besides the burns caused by flames and steam, there are other causative agents, such as chemicals (caustic alkalis and acids), lightning stroke, and occasionally the broken trolley wires of electric railways. When a large surface of the skin is burned or scalded, the animal (if it does not die at once from shock) will soon show signs of fever—shivering, coldness of the extremities, weakness, restlessness, quick and feeble pulse, and labored breathing. No matter which agent is a factor in the production of burns, the lesions are practically of the same nature. The extent and site of the burn should lead one in the determination and course of treatment. Burns of the shoulder and those about the region of the elbow or other parts where there is much movement of the tissues are grave, and, if at all extensive, treatment should not be attempted, but the immediate destruction of the animal is advised. A burn of the third degree, where there is a destruction of the vitality of large areas of tissue, even on parts not subject to much motion, is extremely tedious to treat; in fact, it is questionable whether the treatment and keep of the animal will ever be compensated for, even though recovery does take place; this, in any event, will require at least six or eight weeks. Burns caused by lightning stroke and trolley wires are liable to occur in irregular lines, and, unless death occurs at once, they generally are not serious.

Treatment.—Treatment should be prompt and effective. If the burns are extensive, the constitutional symptoms should be combated with whisky and milk and eggs, or ammonia carbonate, strychnin, caffein, or other stimulant to prevent shock. In the local treatment, to alleviate the pain, the application of cold water in some form and the hypodermic injection of morphine are to be recommended. In burns of the first degree, where there is only a superficial inflammation, lead carbonate (white lead) ointment is very good. Carron oil (limewater and linseed oil, equal parts) is a standard remedy, but a modification of it known as Stahl's liniment is perhaps better. This is composed of linseed oil and limewater each 200 parts, bicarbonate of soda 100 parts, and thymol 1 part. The scorched surface should be covered with this liniment and then with a layer of borated gauze or absorbent cotton, to protect from the air. The application should be frequently renewed. Carbolated vaseline may be used in place of the above. In case the burn is more extensive, the following solution may be used: Picric acid 2 parts, alcohol 40 parts, water 400 parts. The lesion should be thoroughly cleansed with this solution used on absorbent cotton. The vesicles, if any appear, should be opened with a clean needle, allowing the skin to remain. Strips of gauze or absorbent cotton saturated with the solution should now be applied and renewed only occasionally. In burns of the second and third degrees more satisfactory results may be obtained with nonpoisonous, dry dressing powder, such as is used in ordinary open wounds, as tannic acid 8 parts and iodoform 1 part, or a salve made of this powder and a sufficient quantity of vaseline. When sloughing of the tissues takes place the wounds should be cleansed with a warm 3 per cent solution of carbolic acid, all loose fragments of tissue removed, and either a dry, antiseptic dressing powder or carbolated vaseline ointment applied to exclude the air. Granulation tissue (proud flesh) should be controlled by the application of silver nitrate in the form of a caustic pencil.

Burns due to mineral acids may be first treated by flushing the parts with a copious quantity of cold water or by the application of whiting or chalk. Either use a large quantity of water at the start or use the chalk first, then wash with water. If the irritant has been a caustic alkali, such as potash, lye, ammonia, or soda, then vinegar should be the first application. Stahl's liniment is probably the best general application for all burns for the first week; then this should be followed by the ordinary antiseptic wound dressings.

GANGRENE.

Gangrene, or mortification, denotes the death of the affected part, and is mostly found attacking soft tissue near the surface of the body. Gangrenous areas may occur as a result of shutting off their blood supply. Constitutional diseases, such as ergotism, anthrax, and septicemia, predispose to gangrene. As external causes we have acids and alkalies, freezing and burning, contusions and continuous pressure that interrupt the circulation. There are two forms of gangrene—dry and moist. Dry gangrene is most often seen in horses from continuous lying down (decubitus) or from uneven pressure of some portion of the harness.

Symptoms.—There is a lack of sensation due to the death of nerves. In dry gangrene the skin is leathery and harsh, while in moist gangrene the tissues are soft, wrinkled, and friable; the hair is disturbed, and the skin is usually moist and soapy and sometimes covered with blebs. The tissue surrounding the moist gangrenous patch is usually inflamed, swollen, and hot, but this is less noticeable in the case of dry gangrene. Moist gangrene often spreads and involves deeper tissue, sheaths of tendons and joints producing septic synovitis or septic arthritis leading to pyemia and death. Dry gangrene is seldom dangerous, but the rapidity of its spread will indicate its virulence.

Treatment.—The preventive treatment consists in avoiding all the influences that tend to disturb the nutrition of the tissues, such as excessive cold or heat or continuous pressure. Gangrene following decubitus may be prevented by using soft bedding and frequently turning the animal from one side to the other. In dry gangrene moist heat in the form of poultices or anointing the tissue with oils and fats will be found beneficial in hastening the dead tissue to slough off. When the outer skin begins to suppurate, it should be removed with a pair of pincers, and the patch treated as an open wound. In moist gangrene the tissue should be thoroughly disinfected with a 3 per cent solution of compound cresol, or particularly an alcoholic tincture of camphor. Continuous irritation with antiseptic fluids prevents the accumulation and absorption of poisonous liquids. Incisions into the dead tissue may be made, and when sloughing commences the tissue should be removed with forceps and the resulting wound treated as in dry gangrene.

ULCERATION.

An ulcer is a circumscribed area of necrosis occurring on the skin or mucous membrane and covered with granulation tissue. It is a process of destruction, and when this process is going on faster than regeneration can take place, we have a gnawing, or eating, ulcer. When such an ulcer increases rapidly in size it is termed a phagedenic ulcer. A fungoid ulcer is one in which the bottom of the ulcer projects beyond the edge of the skin. These ulcers secrete milky or bloody-white liquid called ichor. When the ulcer is of an ashen or leaden color, with the bottom and sides formed of dense, hard connective tissue, which gives but little discharge and is not sensitive, it is termed callous, torpid, or indolent ulcer.

Causes.—As in the case of gangrene, disturbances of circulation are among the most frequent causes. A wound to a tissue with slight recuperative power may be followed by ulceration, as in tumors. Certain germs may produce ulcers, as the glanders bacilli, which cause the ulcerations on the nasal septum in glanders.

Treatment.—This consists in removing the exciting cause at once. The secretions of the ulcer should be washed off with antiseptic solutions and the formation of granulation tissues stimulated by antiseptic salves, such as carbolated vaseline, lead ointment, or by dressings of camphor. Air should be kept from the ulcer by occlusive dressings. Where the ulcers are inflamed, warm lead water or lead water and laudanum will be found efficacious. Callous ulcers are best removed by a curette, knife, or hot iron and then treated like a common wound. Mechanical irritation should be avoided.

ABSCESSES.

These consist of accumulations of pus within circumscribed walls, at different parts of the body, and may be classed as acute and cold or chronic abscesses.

When an abscess occurs about a hair follicle it is called a boil or furuncle; when several hair follicles are involved, resulting in the formation of more than one exit for the inflammatory products, it is called a carbuncle.

ACUTE ABSCESSES.

Acute abscesses follow as the result of local inflammation in glands, muscular tissue, or even bones. They are very common in the two former. The abscesses most commonly met with in the horse (and the ones which will be here described) are those of the salivary glands, occurring during the existence of "strangles," or "colt distemper." The glands behind or under the jaw are seen to increase slowly in size, becoming firm, hard, hot, and painful. At first the swelling is uniformly hard and resisting over its entire surface, but in a little while becomes soft (fluctuating) at some portion, mostly in the center. From this time on the abscess is said to be "pointing," or "coming to a head," which is shown by a small elevated or projecting prominence, which at first is dry, but soon becomes moist with transuded serum. The hairs over this part loosen and fall off, and in a short time the abscess opens, the contents escape, and the cavity gradually fills up—heals by granulations.

Abscesses in muscular tissue are usually the result of bruises or injuries. In all cases in which abscesses are forming we should hurry the ripening process by frequent hot fomentations and poultices. When they are very tardy in their development a blister over their surface is advisable. It is a common rule with surgeons to open an abscess as soon as pus can be plainly felt, but this practice can scarcely be recommended indiscriminately to owners of stock, since this little operation frequently requires an exact knowledge of anatomy. It will usually be found the better plan to encourage the full ripening of an abscess and allow it to open of itself. This is imperative if the abscess is in the region of joints, etc. When open, we must not squeeze the walls of the abscess to any extent. They may be very gently pressed with the fingers at first to remove the clots—inspissated pus—but after this the orifice is simply to be kept open by the introduction of a clean probe, should it be disposed to heal too soon. If the opening is at too high a level another should be made into the lowest portion of the abscess so as to permit the most complete drainage. Hot fomentations or poultices are sometimes required for a day or two after an abscess has opened, and are particularly indicated when the base of the abscess is hard and indurated.

The cavity should be thoroughly washed with stimulating antiseptic solutions, such as 3 per cent solution of carbolic acid, 3 per cent solution of compound cresol, 1 to 1,000 bichlorid of mercury, or 1 per cent permanganate of potash solution. If the abscesses are foul and bad smelling, their cavities should first be syringed with 1 part of hydrogen peroxid to 2 parts of water and then followed by the injection of any of the above-mentioned antiseptics.

COLD ABSCESSES.

Cold abscess is the term applied to those large, indolent swellings that are the result of a low or chronic form of inflammation, in the center of which there is a small collection of pus. They are often seen near the point of the shoulder, forming the so-called breast boil. The swelling is diffuse and of enormous extent, but slightly hotter than surrounding parts, and not very painful upon pressure. A pronounced stiffness, rather than pain, is evinced upon moving the animal. Such abscesses have the appearance of a hard tumor, surrounded by a softer edematous swelling, involving the tissues to the extent of a foot or more in all directions from the tumor. This diffused swelling gradually subsides and leaves the large, hardened mass somewhat well defined. One of the characteristics of cold abscesses is their tendency to remain in the same condition for a great length of time. There is neither heat nor soreness; no increase nor lessening in the size of the tumor; it remains in statu quo. If, however, the animal should be put to work for a short time the irritation of the collar causes the surrounding tissues to assume again an edematous condition, which after a few days' rest disappears, leaving the tumor as before or but slightly larger. Upon careful manipulation we may discover what appears to be a fluid deep seated in the center of the mass. The quantity of matter so contained is very small—often not more than a tablespoonful—and for this reason it can not, in all cases, be detected.

Cold abscesses are mostly, if not always, caused by the long-continued irritation of a loose and badly fitting collar. There is a slow inflammatory action going on, which results in the formation of a small quantity of matter inclosed in very thick and but partially organized walls that are not so well defined as is the circumference of fibrous tumors, which they most resemble.

Treatment.—The means recommended to bring the acute abscess "to a head" are but rarely effectual with this variety; or, if successful, too much time has been occupied in the cure. We must look for other and more rapid methods of treatment. These consist, first of all, in carefully exploring the tumor for the presence of pus. The incisions must be made over the softest part and carried deep into the tumor—to its very bottom, if necessary—and the matter allowed to escape. After this, and whether we have found matter or not, we must induce an active inflammation of the tumor, in order to promote solution of the thick walls of the abscess. This may be done by inserting well into the incision a piece of oakum or cotton saturated with turpentine, carbolic acid, tincture of iodin, etc., or we may pack the incision with powdered sulphate of zinc and keep the orifice plugged for 24 hours. These agents set up a destructive inflammation of the walls. Suppuration follows, and this should now be encouraged by hot fomentations and poultices. The orifice must be kept open, and should it be disposed to heal we must again introduce some of the agents above described. A favored treatment with many, and it is probably the best, is to plunge a red-hot iron to the bottom of the incision and thoroughly sear all parts of the walls of the abscess. This is to be repeated after the first slough has taken place if the walls remain thickened and indurated.

It is useless to waste time with fomentations, poultices, or blisters in the treatment of cold abscesses, since though apparently removed by such methods, they almost invariably return when the horse is put to work. Extirpation by the knife is not practicable, as the walls of the tumor are not sufficiently defined. If treated as above directed, and properly fitted with a good collar after healing, there will not remain any track or trace of the large, unsightly mass.

FISTULAS.

Definition.—The word fistula is applied to any ulcerous lesion upon the external surface of the body which is connected by ducts, or passages, with some internal cavity. Because of this particular formation the term fistulous tract is often used synonymously with the word fistula. Fistulas may exist in any part of the body, but the name has come to be commonly accepted as applicable only to such lesions when found upon the withers. Poll evil is a fistula upon the poll, and in no sense differs from fistulous withers except in location. The description of fistula will apply, then, in the main, to poll evil equally well. Quittor presents the characteristic tubular passages of a fistula and may, therefore, be considered and treated as fistula of the foot. Fistulous passages may also be developed upon the sides of the face, through which saliva is discharged instead of flowing into the mouth, and are called salivary fistulas. A dental fistula may arise from the necrosis of the root of a tooth. Again, a fistula is sometimes noted at the umbilicus associated with hernia, and recto-vaginal fistulas have been developed in mares, following difficult parturition. Fistulas may arise from wounds of glandular organs or their ducts, and thus we have the so-called mammary or lacrimal fistulas.

Fistulous tracts are lined with a false, or adventitious, membrane and show no disposition to heal. They constantly afford means of exit to the pus or ichorous material discharged by the unhealthy parts below. They are particularly liable to develop at the withers or poll because of the exposed positions which these parts occupy, and, having once become located there, they usually assert a tendency to further extension, because the vertical and laminated formation of the muscles and tendons of these parts allows the forces of gravitation to assist the pus in gaining the deeper-lying structures and also favors its retention among them.

Causes.—Fistulas follow as a result of abscesses, bruises, wounds, or long-continued irritation by the harness. Among the more common causes of fistula of the poll (poll evil) are chafing by the halter or heavy bridle; blows from the butt end of the whip; the horse striking his head against the hayrack, beams of the ceiling, low doors, etc. Fistulous withers are seen mostly in those horses that have thick necks as well as those that are very high in the withers; or, among saddle horses, those that are very low in the withers, the saddle here riding forward and bruising the parts. In either of these locations ulcers of the skin, or simple abscesses, if not properly and punctually treated, may become fistulas. They are often caused by bad-fitting collars or saddles, by direct injuries from blows, and from the horse rolling upon rough or sharp stones. The pus burrows and finds lodgment deep down between the muscles, and escapes only when the sinus becomes surcharged or when, during motion of the parts, the matter is forced to the surface.

Symptoms.—These, of course, will vary according to the progress made by the fistula. Following an injury we may often notice soreness or stiffness of the front legs, and upon careful examination of the withers we see small tortuous lines running from the point of irritation downward and backward over the region of the shoulder. These are superficial lymphatics, and are swollen and painful to the touch. In a day or two a swelling is noticed on one or both sides of the dorsal vertebrae, which is hot, painful, and rapidly enlarging. The stiffness of the limbs may disappear at this time, and the heat and soreness of the parts may become less noticeable, but the swelling remains and continues to enlarge.

A fistulous ulcer of the poll may be first indicated by the opposition which the animal offers to the application of stable brush or bridle. At this time the parts are so sore and sensitive that there is some danger that unless handled with the greatest care the patient will acquire disagreeable stable habits. The disease in its early stages may be recognized as a soft, fluctuating tumor surrounded by inflammatory swelling, with the presence of enlarged lymphatic vessels and stiffness of the neck. Later the inflammation of the surrounding tissues may disappear, leaving a prominent tumor. The swelling, whether situated upon the head or the withers, may open and form a running ulcer, or its contents may dry up and leave a tumor which gradually develops the common characteristics of a fibrous tumor. When the enlargement has opened we should carefully examine its cavity, as upon its condition will wholly depend our treatment.

Treatment.—In the earliest stage, when there is soreness, enlarged lymphatics, but no well-marked swelling, the trouble may frequently be aborted. To do this requires both general and local treatment. A physic should be given, and the horse receive 1 ounce of powdered saltpeter three times a day in his water or feed. If the fever runs high, 20-drop doses of tincture of aconite root every two hours may be administered. The local application of cold water to the inflamed spot for an hour at a time three or four times a day has often proved very beneficial, and has afforded great relief.

Cooling lotions, muriate of ammonia, or saltpeter and water; sedative washes, such as tincture of opium and aconite, chloroform liniment, or camphorated oil, are also to be frequently applied. Should this treatment fail to check the progress of the trouble, the formation of pus should be hastened as rapidly as possible. Hot fomentations and poultices are to be constantly used, and as soon as the presence of pus can be detected, the abscess wall is to be opened at its lowest point. In this procedure lies our hope of a speedy cure. As with any simple abscess, if drainage can be so provided that the pus will run off as fast as formed without remaining within the interstices of the tissues, the healing will be rapid and satisfactory.

Attention is again called to the directions given above as to the necessity of probing the cavity when opened. If upon a careful examination with the probe we find that there are no pockets, no sinuses, but a simple, regular abscess wall, the indication for treatment is to make an opening from below so that all the matter must escape. Rarely is anything more needed than to keep the orifice open and to bathe or inject the parts with some simple antiseptic wash that is not irritant or caustic. A low opening and cleanliness constitute the essential and rational treatment.

If the abscess has already opened, giving vent to a quantity of purulent matter, and the pipes and tubes leading from the opening are found to be extensive and surrounded with thick fungoid membranes, there is considerable danger that the internal ligaments or even some of the bones have become affected, in which case the condition has assumed a serious aspect. Or, on the other hand, if the abscess has existed for some time without a rupture, its contents will frequently be found to consist of dried purulent matter, firm and dense, and the walls surrounding the mass will be found greatly thickened. In such a case we must generally have recourse to the application of caustics which will cause a sloughing of all of the unhealthy tissue, and will also stimulate a rapid increase of healthy organized material to replace that destroyed in the course of the development and treatment of the disease. Threads or cords soaked in gum-arabic solution and rolled in powdered corrosive sublimate may be introduced into the canal and allowed to remain. The skin on all parts of the shoulder and leg beneath the fistula should be carefully greased with lard or oil, as this will prevent the discharge that comes from the opening after the caustic is introduced from irritating or blistering the skin over which it flows. In obstinate cases a piece of caustic potash (fused) 1 to 2 inches in length may be introduced into the opening and should be covered with oakum or cotton. The horse should then be secured so that he can not reach the part with his teeth. After the caustic plug has been in place for 24 hours, it may be removed and hot fomentations applied. As soon as the discharge has become again established the abscess should be opened from its lowest extremity, and the passage thus formed may be kept open by the introduction of a seton. If the pipes become established in the deep tissues beneath the shoulder blade or among the spines of the vertebral column, it will often be found impossible to provide proper drainage for the abscess from below, and treatment must consist of caustic solutions carefully injected into all parts of the suppurating sinuses. A very effective remedy for this purpose consists of 1 ounce of chlorid of zinc in half a pint of water, injected three times during a week, after which a weak solution of the same may be occasionally injected. Injections of Villate's solution or alcoholic solution of corrosive sublimate, strong carbolic acid, or possibly oil of turpentine will also prove beneficial. Pressure should be applied from below, and endeavors made to heal the various pipes from the bottom.

Should the swelling become general, without forming a well-defined tumor, the placing of 20 to 30 grains of arsenious acid, wrapped in a single layer of tissue paper, in a shallow incision beneath the skin, will often produce a sloughing of the affected parts in a week or 10 days, after which the formation of healthy tissue follows. The surrounding parts of the skin should be protected from any damage from escaping caustics by the application of lard or oil, as previously suggested.

Although the successful treatment of fistulas requires time and patience, the majority of cases are curable. The sinuses must be opened at their lowest extremity and kept open. Caustic applications must be thoroughly used once or twice, after which mild astringent antiseptic washes should be persistently used until a cure is reached.

It sometimes happens that the erosions have burrowed so deeply or in such a direction that the opening of a drainage passage becomes impracticable. In other cases the bones may be attacked in some inaccessible location, or the joints may be affected, and in these cases it is often best to destroy the horse at once.

The reappearance of the fistula after it has apparently healed is not uncommon. The secondary attack in these cases is seldom serious. The lesion should be carefully cleaned and afterwards injected with a solution of zinc sulphate, 20 grains to the ounce of water, every second or third day until a cure is effected.

In fistula of the foot we see the same tendency toward the burrowing of pus downward to lower structures, or in some cases upward toward the coronet. Prior to the development of a quittor there is always swelling at the coronet, accompanied with heat and pain. Every effort should now be made to prevent the formation of an abscess at the point of injury. Wounds caused by nails, gravel, or any other foreign body which may have lodged in the sole of the foot should be opened at once from below, so as to allow free exit to all purulent discharges. Should the injury have occurred directly to the coronet the application of cold fomentations may prove efficient in preventing the formation of an abscess.

When a quittor becomes fully established it should be treated precisely as a fistula situated in any other part of the body; that is, the sinuses should all be opened from their lowest extremities, so as to afford constant drainage. All fragments of diseased tissue should be trimmed away, antiseptic solutions injected, and, after covering the wound with a pad of oakum saturated with some good antiseptic wash, the whole foot may be carefully covered with clean bandages, which will afford valuable assistance to the healing process by excluding all dirt from the affected part.

Another form of treatment for this class of infections consists in the use of bacterial vaccines. Such treatment appears to be well adapted for the purpose, and according to current veterinary literature has met with success. These vaccines are composed of several strains of the organisms usually found in these pustular infections of the horse. Two kinds of vaccines are used: First, autogenic vaccines, which consist of heated (killed) cultures of the organism or organisms which are causing the trouble and which have been isolated from the lesions; second, stock vaccines, consisting of dead organisms of certain species generally found in these lesions and which are used in diseased conditions caused by one or the other of these germs. The vaccine is administered subcutaneously by means of a syringe, but the quantity of the vaccine to be injected and the number of doses to be used should be left to the judgment of a competent veterinarian.



INFECTIOUS DISEASES.

By RUSH SHIPPEN HUIDEKOPER, M. D., Vet.

[Revised by A. Eichhorn, D. V. S.]

GENERAL DISCUSSION.

An infectious disease may be defined as any malady caused by the introduction into the body of minute organisms of the vegetable or animal kingdom which have the power to multiply indefinitely and set free certain peculiar poisons which are chiefly responsible for morbid changes. Nearly all diseases of animals for which a definite cause may be attributed are caused by bacteria; such are tuberculosis, anthrax, blackleg, lockjaw, and others. There are some diseases, as, for instance, Texas fever and rabies, which are caused by a minute animal parasite known as protozoa, while others again, like lumpy jaw and aspergillosis, are caused by fungi. Besides there are infectious diseases in which the causative agents have never been successfully isolated, as they are so small that they can not be detected by the aid of the most powerful microscope, and accordingly they are termed as ultravisible viruses. Hog cholera, foot-and-mouth disease, smallpox, and others belong to this group.

Bacteria may be defined as very minute unicellular organisms of plantlike character. They multiply either by simple division or by spore formation, the latter usually taking place when the conditions pertaining to the growth of the bacteria become unfavorable. The spores are much more resistant to destruction than the bacteria which produce them.

Another group of parasites producing disease is known as protozoa. These are more complex than bacteria, and their artificial cultivation is also much more difficult than is the case with the bacterial parasites. Of the representatives of this group, causing disease in animals, are the trypanosomes, which are the causative factors of dourine and surra, and the piroplasma, which induce Texas fever in cattle and malaria or biliary fever of horses. There are also disease-producing fungi which are responsible for certain affections in horses; among these the most important are mycotic lymphangitis, or sporotrichosis, and streptotrichosis.

The introduction of the infection may take place in various ways. The most frequent method is by ingestion. Further, the entrance of the germs may occur by inhalation, skin abrasions, wounds of any kind, through the genital organs, and at times also through the milk ducts of the teats. As a general rule infectious diseases have a period of incubation which comprises the time elapsing between the exposure to the infection and the actual appearance of the disease. This period varies in the different diseases.

The treatment of infectious diseases is, as a rule, unsatisfactory. When the symptoms have once appeared a disease is liable to run its course in spite of treatment, and if it is one from which animals usually recover, all that can be done is to put them into the most favorable surroundings. Many infectious diseases lead sooner or later to death; treatment is useless so far as the sick animals are concerned, and it may be worse than useless for those not yet affected. All animals suffering with infectious diseases are more or less directly a menace to all others. They represent for the time being manufactories of disease germs, and they are giving them off more or less abundantly during the period of disease. They may infect others directly or they may scatter the virus about and the surroundings may become the future source of infection.

Therefore, in the control of infectious diseases prevention is the most important procedure. The isolation or segregation of healthy animals from infected ones should be primarily considered, and if at any time an animal manifests the symptoms of an infectious disease it is essential to protect the others from such a source of danger. In some of the infectious diseases it may become advisable to kill the infected animals in order to avoid the spread of the disease. This is especially important in diseases which are slow in their course, such as tuberculosis. At times when diseases appear in a country where they have not been prevalent it becomes advisable and necessary to protect the healthy herds by the slaughter of all the infected animals. Pursuance of this policy has resulted in control of the foot-and-mouth disease, and has proved to be a very satisfactory method of eradication.

DISINFECTION.

Disinfection is a very important phase in the control of infectious disease. This consists in the use of certain substances which possess the power to destroy bacteria or their spores, or both. The cheapest and most available for animal diseases are ordinary freshly slaked lime, or unslaked lime in powder form, chlorid of lime, crude carbolic acid, corrosive sublimate, formalin, formaldehyde, gas, cresol, etc.

In the disinfection of stables and premises it is essential to execute the work in a most thorough manner. This may be satisfactorily accomplished by carrying out the following directions:

1. Sweep ceilings, side walls, stall partitions, floors, and other surfaces until free from cobwebs and dust.

2. Scrape away all accumulation of filth, and if woodwork has become decayed, porous, or absorbent, it should be removed, burned, and replaced with new material.

3. If floor is of earth, remove 4 inches from the surface, and in places stained with urine a sufficient depth should be replaced to expose fresh earth. All earth removed should be replaced with earth from an uncontaminated source; it would be better still to lay a new floor of concrete, which is very durable and easily cleaned.

4. All refuse and material from stable and barnyard should be removed to a place not accessible to cattle or hogs. The manure should be spread on fields and turned under, while the wood should be burned.

5. The entire interior of the stable, especially the feeding troughs and drains, should be saturated with a disinfectant, as liquor cresolis compositus (U. S. P.), or carbolic acid, 6 ounces to every gallon of water, to which 4 ounces of chlorid of lime should be added. The best method of applying the disinfectant and the lime wash is by means of a strong spray pump, such as those used by orchardists. This method is efficient in disinfection against most of the contagious and infectious diseases of animals, and should be applied immediately following any outbreak, and, as a matter of precaution, it may be used once or twice yearly.

6. It is important that arrangements be made to admit a plentiful supply of sunlight and fresh air by providing an ample number of windows, thereby eliminating dampness, bad odor, and other insanitary conditions. Good drainage is also very necessary.

If the use of liquor cresolis compositus, carbolic acid, or other coal-tar products is inadmissible because of the readiness with which their odor is imparted to milk and other dairy products, bichlorid of mercury may be used in proportion of 1 to 800, or 1 pound of bichlorid to 100 gallons of water. All portions of the stable soiled with manure, however, should first be thoroughly scraped and cleaned, as the albumin contained in manure would otherwise greatly diminish the disinfecting power of the bichlorid. Disinfection with this material should be supervised by a veterinarian or other person trained in the handling of poisonous drugs and chemicals, as the bichlorid is a powerful, corrosive poison. The mangers and the feed boxes, after drying, following spraying with this material, should be washed out with hot water, as cattle are especially susceptible to mercurial poisoning. The bichlorid solution should be applied by means of a spray pump, as recommended for the liquor cresolis compositus.

VACCINATION.

In recent years vaccination for the prevention of certain infectious diseases has been successfully developed, and without a doubt the future has a great deal in store for this phase of prevention. At the present time vaccination has been found effective against blackleg, hog cholera, anthrax, lockjaw, strangles, rabies, hemorrhagic septicemia, white scours, etc. It is always essential, of course, that the products used for the vaccination be pure and potent; also they should be employed only with the advice of competent authorities and with proper care. The biological products prepared for the cure and prevention of infections are prepared by manufacturers who, in order to conduct an interstate business, are required to obtain a license from the United States Department of Agriculture for the manufacture of such preparations.

Since July 1, 1913, the Department of Agriculture, by an act of Congress of March 4, 1913, has had control of the manufacture of biological products for the treatment of domestic animals. The numerous complaints which were received from time to time relative to the impotency of some of the preparations, and also the fact that in some instances the use of the products were directly responsible in causing outbreaks of disease, made the necessity for such control obvious. This supervision is no doubt of far-reaching importance, as it assures the users that the preparations are reliable.

INFLUENZA.

Synonyms.—Pinkeye, typhoid fever, epizooty, epihippic fever, hepatic fever, bilious fever, etc.; flevre typhoide, grippe (French); Pferdestaupe (German); gastro-enteritis of Vatel and d'Arboval; febris erysipelatodes, Zundel; typhus of Delafond.

Definition.—The term influenza is applied to a febrile, contagious, infectious disease of horses, which is characterized by a blood infection, with inflammation of the mucous membranes, which frequently involves the lungs. Inflammatory complications also occur in the form of swellings of the subcutis, tendons, and tendinous sheaths and laminae of the feet. The causative agent has not been satisfactorily established. One attack usually protects the animal from future ones of the same disease, but not always. An apparently complete recovery is sometimes followed by serious sequelae of the nervous and blood-vessel systems. Under certain conditions of the atmosphere or from unknown causes, the disease is very liable to assume an epizootic form, with tendency to complications of especial organs, as, at one period, the lungs, at another the intestines, etc.

The first description of influenza is given by Laurentius Rusius in 1301, when it spread over a considerable portion of Italy, causing great loss among the war horses of Rome and the surrounding district. Later, in 1648, an epizootic of this disease visited Germany and spread to other parts of Europe. In 1711, under the name of "epidemica equorum," it followed the tracks of the great armies all over Europe, causing immense losses among the horses, while rinderpest was scourging the cattle of the same regions. The two diseases were confounded with each other, and were, by the scientists of the day, supposed to be allied to the typhus, which was a plague to the human race at the same time. We find the first advent of this disease to the British Islands in an epizootic among the horses of London and the southern counties of England in 1732, which is described by Gibson. In 1758 Robert Whytt recounts the devastation of the horses of the north of Scotland from the same trouble. Throughout the eighteenth century a number of epizootics occurred in Hanover and other portions of Germany and in France, which were renewed early in the present century, with complications of the intestinal tract, which obtained for it its name of gastro-enteritis. In 1766 it first attacked the horses in North America, but is not described as again occurring in a severe form until 1870-1872, when it spread over the entire country, from Canada south to Ohio, and then eastward to the Atlantic and westward to California. It is now a permanent disease in our large cities, selecting for the continuance of its virulence young or especially susceptible horses which pass through the large and ill-ventilated and uncleaned stables of dealers, and assumes from time to time an enzootic form, when from some reason its virulence increases. It assumes this form also when, from reasons of rural economy and commerce, large numbers of young and more susceptible animals are exposed to its contagion.