Straw. The straws are not extensively fed in this country, and when used at all they should be cut and mixed with hay and ground or crushed grain. Wheat, rye, and oat straw are the ones most used; of these, oat straw is most easily digested and contains the most nourishment. Pea and bean straw are occasionally fed to horses, the pea being preferable, according to most writers.
The average horse on grain should be allowed from 10 to 12 pounds of good hay a day. It is a mistake of many to think that horses at light work can be kept entirely on hay. Such horses soon become potbellied, fall off in flesh, and do not thrive. The same is true of colts; unless the latter are fed with some grain they grow up to be long, lean, gawky creatures, and never make so good horses as those accustomed to grain with, or in addition to, their hay.
Second crop, or aftermath. This is not considered good hay for horses, but it is prized by some farmers as good for milch cows, the claim being made that it increases the flow of milk. The value of hay depends upon the time of cutting, as well as care in the curing. Hay should be cut when in full flower, but before the seeds fall; if left longer it becomes dry, woody, and lacks in nutrition. An essential point in making hay is that when the crop is cut it should remain in the field as short a time as possible. If left too long in the sun it loses color, flavor, and dries or wastes. Smith asserts that one hour more than is necessary in the sun causes a loss of 15 to 20 per cent in the feeding value of hay. It is impossible to state any fixed time that hay must have to cure, this depending, of course, upon the weather, thickness of the crop, and many other circumstances; but it is well known that in order to preserve the color and aroma of hay it should be turned or tedded frequently and cured as quickly as possible. On the other hand, hay spoils in the mow if harvested too green or when not sufficiently dried. Mow-burnt hay produces disorder of the kidneys and bowels and causes the horse to fall off in condition.
Hay. The best hay for horses is timothy. It should be about one year old, of a greenish color, crisp, clean, fresh, and possessing a sweet, pleasant aroma. Even this good hay, if kept too long, loses part of its nourishment, and, while it may not be positively injurious, it is hard, dry, and indigestible. New hay is difficult to digest, produces much salivation (slobbering), and occasional purging and irritation of the skin. If fed at all it should be mixed with old hay.
Feeds should also be of a more laxative nature when the horse is to stand for several days.
Musty or moldy feeds. Above all things, avoid feeding musty or moldy feeds. They are very frequent causes of disease of different kinds. Lung trouble, such as bronchitis and "heaves," often follows their use. The digestive organs always suffer from moldy or musty feeds. Musty hay is generally considered to produce disorder of the kidneys, and all know of the danger from feeding pregnant animals upon ergotized grasses or grains. It has often been said to produce that peculiar disease known variously as cerebrospinal meningitis, putrid sore throat, or choking distemper.
Sudden changes of diet are always dangerous. When desirous of changing, do so very gradually. If a horse is accustomed to oats, a sudden change to a full meal of corn will almost always sicken him. If we merely intend to increase the quantity of the usual feed, this also must be done gradually. The quantity of feed given must always be in proportion to the amount of labor to be performed. If a horse is to do a small amount of work, or rest entirely from work for a few days, he should receive a proportionate quantity of feed. If this should be observed even on Saturday night and Sunday, there would be fewer cases of "Monday morning sickness," such as colics and lymphangitis.
The stomach begins to empty itself very soon after the commencement of feeding, and continues rapidly while eating. Afterwards the passage is slower, and several hours are required before the stomach is entirely empty. The nature of the work required of the horse must guide us in the selection of his feed. Rapid or severe labor can not be performed on a full stomach. For such labor feed must be given in small quantity and about two hours before going to work. Even horses intended for slow work must never be engorged with bulky, innutritious feed immediately before going to labor. The small stomach of the horse would seem to lead us to the conclusion that he should be fed in small quantities and often, which, in reality, should be done. The disproportion between the size of the stomach and the quantity of water drunk tells us plainly that the horse should always be watered before feeding. One of the common errors of feeding, and the one that produces more digestive disorders than any other, is to feed too soon after a hard day's work. This must never be done. If a horse is completely jaded, it will be found beneficial to give him an alcoholic stimulant on going into the stable. A small quantity of hay may then be given, but his grain should be withheld for one or two hours. These same remarks will apply with equal force to the horse that for any reason has been fasting for a long time. After a fast, feed less than the horse would eat, for if allowed too much the stomach becomes engorged, its walls paralyzed, and "colic" is almost sure to follow. The horse should be fed three or four times a day. It will not do to feed him entirely upon concentrated feed. Bulky feed must be given to detain the grains in their passage through the intestinal tract; bulk also favors distention, and thus mechanically aids absorption. For horses that do slow work the greater part of the time, chopped or cut hay fed with crushed oats, ground corn, etc., is the best manner of feeding, as it gives the required bulk, saves time, and half the labor of feeding.
The length of time occupied by stomach digestion in the horse varies with the different feeds. Hay and straw pass out of the stomach more rapidly than oats. It would seem to follow, then, that oats should be given after hay, for if reversed the hay would cause the oats to be sent onward into the intestines before being fully acted upon by the stomach, and as a result produce indigestion. Experience confirms this. There is another good reason why hay should be given first, particularly if the horse is very hungry or if exhausted from overwork, namely, it requires more time in mastication (insuring proper admixture of saliva) and can not be bolted, as are the grains. In either instance water must not be given soon after feeding, as it washes or sluices the feed from the stomach before it is fitted for intestinal digestion.
In selecting feed for the horse we should remember the anatomical arrangement of the digestive organs, as well as the physiological functions performed by each one of them. Feeds must be wholesome, clean, and sweet, the hours of feeding regular, the mode of preparation found by practical experience to be the best must be adhered to, and cleanliness in preparation and administration must be observed.
In the horse digestion takes place principally in the intestines, and here, as in all other animals and with all feeds, it is found that a certain part only of the provender is digested; another portion is undigested. This proportion of digested and undigested feed must claim passing notice at least, for if the horse receives too much feed, or bulky feed containing much indigestible waste, a large portion of it must pass out unused, entailing not only the loss of this unused feed, but also calling for an unnecessary expenditure of vital force on the part of the digestive organs of the horse. It is thus that, in fact, too much feed may make an animal poor.
We can not, however, leave aside entirely here a consideration of the digestibility of feeds; and by this we mean the readiness with which they undergo those changes in the digestive canal that fit them for absorption and deposition as integral parts of the animal economy.
The age and health of the animal will, of course, modify the digestibility of feeds, as will also the manner and time of harvesting, preserving, and preparing.
In this country horses are fed chiefly upon hay, grass, corn fodder, roots, oats, corn, wheat, and rye. Many think that they could be fed on nothing else. Stewart, in "The Stable Book," gives the following extract from Loudon's Encyclopedia of Agriculture, which is of interest at this point:
In some sterile countries they (horses) are forced to subsist on dried fish, and even on vegetable mold; in Arabia, on milk, flesh balls, eggs, broth. In India horses are variously fed. The native grasses are judged very nutritious. Few, perhaps no, oats are grown; barley is rare, and not commonly given to horses. In Bengal a vetch, something like the tare, is used. On the western side of India a sort of pigeon pea, called gram (Cicer arietinum), forms the ordinary food, with grass while in season, and hay all the year round. Indian corn or rice is seldom given. In the West Indies maize, guinea corn, sugar-corn tops, and sometimes molasses are given. In the Mahratta country salt, pepper, and other spices are made into balls, with flour and butter, and these are supposed to produce animation and to fine the coat. Broth made from sheep's head is sometimes given. In France, Spain, and Italy, besides the grasses, the leaves of limes, vines, the tops of acacia, and the seeds of the carob tree are given to horses.
In this place one can not attempt anything like a comprehensive discussion of the subject of feeds and feeding, and I must content myself with merely giving a few facts as to the different kinds of feed, preparation, digestibility, proper time of feeding, quality, and quantity. Improper feeding and watering will doubtless account for more than one-half the digestive disorders met with in the horse, and hence the reader can not fail to see how very important it is to have some proper ideas concerning these subjects.
The chief impurities of water may be classified as organic and inorganic. The organic impurities are either animal or vegetable substances. The salts of the metals are the inorganic impurities. Lime causes hardness of water, and occasion will be taken to speak of this when describing intestinal concretions. Salts of lead, iron, and copper are also frequently found in water; they also will be referred to.
About the only examination of water that can be made by the average stock raiser is to observe its taste, color, smell, and clearness. Pure water is clear and is without taste or smell.
Chemical and microscopic examination will frequently be necessary in order to detect the presence of certain poisons, bacteria, etc., and can, of course, be conducted by experts only.
In reference to the purity of water, Smith, in his "Veterinary Hygiene," classes spring water, deep-well water, and upland surface water as wholesome; stored rain water and surface water from cultivated land as suspicious; river water to which sewage gains access and shallow-well water as dangerous. The water that is used so largely for drinking purposes for stock throughout some States can not but be impure. I refer to those sections where there is an impervious clay subsoil. It is the custom to scoop, or hollow out, a large basin in the pastures. During rains these basins become filled with water. The clay subsoil, being almost impervious, acts as a jug, and there is no escape for the water except by evaporation. Such water is stagnant, but would be kept comparatively fresh by subsequent rains were it not for the fact that much organic matter is carried into it by surface drainage during each succeeding storm. This organic matter soon undergoes decomposition, and, as the result, we find diseases of different kinds much more prevalent where this water is drunk than where the water supply is wholesome. Again, it must not be lost sight of that stagnant surface water is much more certainly contaminated than is running water by one diseased animal of the herd, thus endangering the remainder.
Ice-cold water should never be given to horses. It may not be necessary to add hot water, but we should be careful in placing water troughs about our barns to have them in such position that the sun may shine upon the water during the winter mornings. Water, even though it is thus cold, seldom produces serious trouble if the horse has not been deprived for a too great length of time.
The time of giving water should be carefully studied. At rest, the horse should receive it at least three times a day; when at work, more frequently. The rule should be to give it in small quantities and often. There is a popular fallacy that if a horse is warm he should not be allowed to drink, many asserting that the first swallow of water "founders" the animal or produces colic. This is erroneous. No matter how warm a horse may be, it is always entirely safe to allow him from six to ten swallows of water. If this is given on going into the stable, he should have at once a pound or two of hay and allowed to rest about an hour before feeding. If water is now offered him it will in many cases be refused, or at least he will drink but sparingly. The danger, then, is not in the "first swallow" of water, but is due to the excessive quantity that the animal will take when warm if he is not restrained.
Considering first the quantity of water required by the horse, it may be stated that when our animals have access to water continually they never drink to excess. Were the horse subjected to ship voyages or any other circumstances where he must depend upon his attendant for the supply of water, it may be roughly stated that he requires a daily average of about 8 gallons of water. This varies somewhat upon the character of his feed; if upon green feed, less water will be needed than when fed upon dry hay and grain.
It is generally held, at least in practice, that any water that stock can be induced to drink is sufficiently pure for their use. This practice occasions losses that would startle us if statistics were at hand. Water that is impure from the presence of decomposing organic matter, such as is found in wells and ponds in close proximity to manure heaps and cesspools, is frequently the cause of diarrhea, dysentery, and many other diseases of stock, while water that is impregnated with different poisons and contaminated in very many instances with specific media of contagion produces death.
It is not an easy task to write "a plain account of the common diseases, with directions for preventive measures, hygienic care, and the simpler forms of medical treatment," of the digestive organs of the horse. Being limited as to space, the endeavor has been made to give simply an outline to state the most important facts leaving many gaps, and continually checking the disposition to write anything like a full description as to cause, prevention, and modes of treatment of diseases.
Ordinary cold water or even ice-cold water is highly recommended by many as a rectal injection for horses overcome by the excessive heat of summer, and may be given by this simple pipe.
By the genito-urinary passages. This method of medication is especially useful in treating local diseases of the genito-urinary organs. It finds its chief application in the injection and cleansing of the uterus and vagina. For this purpose a large syringe or the irrigator described above may be used.
By the blood. Injections directly into veins are to be practiced by medical or veterinary practitioners only, as are probably some other means of giving medicines intratracheal injections, etc.
Liquids may be thrown into the rectum by the means of a large syringe or a pump. A very good "irrigator" can be bought of any tinsmith at a trifling cost, and should be constantly at hand on every stock farm. It consists of a funnel about 6 inches deep and 7 inches in diameter, which is to be furnished with a prolongation to which a piece of rubber hose, such as small garden hose, 4 feet long may be attached. The hose, well oiled, is to be inserted gently into the rectum about 2 feet. The liquid to be injected may then be poured in the funnel and the pressure of the atmosphere will force it into the bowels. This appliance is better than the more complicated and expensive ones.
Suppositories are conical bodies made up of oil of theobroma and opium (or whatever medicine is indicated in special cases), and are introduced into the rectum or vagina to allay irritation and pain of these parts. They are not much used in treating horses.
Enemas, when given for absorption, should be small in quantity, neutral or slightly acid in reaction, and of a temperature of from 90° to 100° F. These, like feeds given by the rectum, should be introduced only after the last bowel has been emptied by the hand or by copious injections of tepid water. Enemas, or clysters, if to aid the action of physics, should be in quantities sufficient to distend the bowel and cause the animal to eject them. Simple water, salt and water, or soap and water, in quantities of a gallon or more, may be given every half hour. It is best that the horse retain them for some little time, as the liquid serves to moisten the dung and favors a passage. Stimulating enemas, as glycerin, should be administered after those already mentioned have emptied the last bowel, with the purpose of still further increasing the natural motion of the intestines and aiding the purging medicine.
By the rectum. Medicines may be given by the rectum when they can not be given by the mouth, or when they are not retained in the stomach; when we want a local action on the last gut; when it is desired to destroy the small worms infesting the large bowels or to stimulate the peristaltic motion of the intestines and cause evacuation. Medicines are in such cases given in the form of suppositories or as liquid injections (enemas.) Foods may also be given in this way.
By the tissue beneath the skin (hypodermatic method). Medicines are frequently given by the hypodermic syringe under the skin. It is not safe for any but medical or veterinary practitioners to use this form of medication, since the medicines thus given are powerful poisons. There are many precautions to be observed, and a knowledge of anatomy is indispensable. One of the chief precautions has to do with the sterilization of the syringe. If it is not sterile an abscess may be produced.
By the skin. Medicines are often administered to our hair-covered animals by the skin, yet care must be taken in applying some medicines as tobacco water, carbolic-acid solutions, strong creolin solutions, mercurial ointment, etc. over the entire body, as poisoning and death follow in some instances from absorption through the skin. For the same reasons care must also be exercised and poisonous medicines not applied over very large raw or abraded surfaces. With domestic animals medicines are only to be applied by the skin to allay local pain or cure local disease.
Injections are made into the trachea by means of a hypodermic syringe. This method of medication is used for the purpose of treating local diseases of the trachea and upper bronchial tubes. It has also been used as a mode of administering remedies for their constitutional effect, but is now rarely used for this purpose.
The nasal douche is employed by the veterinarian in treating some local diseases of the nasal chambers. Special appliances and professional knowledge are necessary when using liquid medicines by this method. It is not often resorted to, even by veterinary surgeons, since, as a rule, the horse objects very strongly to this mode of medication.
By the air passages. Medicines are administered to the lungs and upper air passages by insufflation, inhalation, injection, and nasal douche.
Insufflation consists in blowing an impalpable powder directly into the nose. It is but rarely resorted to.
Inhalation. Gaseous and volatile medicines are given by inhalation, as is also medicated steam or vapor. Of the gases used there may be mentioned, as the chief ones, sulphurous acid gas and, occasionally, chlorin. The animal or animals are to be placed in a tight room, where these gases are generated until the atmosphere is sufficiently impregnated with them. Volatile medicines as the anesthetics (ether, chloroform, etc.) are to be given by the attending surgeon only. Medicated vapors are to be inhaled by placing a bucket containing hot water, vinegar and water, scalded hay or bran, to which carbolic acid, iodin, compound tincture of benzoin, or other medicines have been added, in the bottom of a long grain bag. The horse's nose is to be inserted into the top of the bag, and he thus inhales the "medicated steam." Care must be taken not to have it hot enough to scald the animal. The vapor from scalding bran or hay is often thus inhaled to favor discharges in sore throat or "distemper."
Do not rub, pinch, or pound the throat nor draw out the tongue when giving a drench. These processes in no way aid the horse to swallow and oftener do harm than good. In drenching, swallowing may be hastened by pouring into the nose of the horse, while the head is high, a few teaspoonfuls of clean water, but drenches must never be given through the nose. Large quantities of medicine given by pouring into the nose are liable to strangle the animal, or, if the medicine is irritating, it sets up an inflammation of the nose, fauces, windpipe, and sometimes the lungs.
When medicine is to be given as a drench we must be careful to use water or oil enough to dissolve or dilute it thoroughly; more than this Wakes the drench bulky and is unnecessary. Insoluble medicines, if not irritant or corrosive, may be given simply suspended in water, the bottle to be well shaken immediately before giving the drench. The bottle used for drenching purposes should be clean, strong, and smooth about its neck; it should be without shoulders, tapering, and of a size to suit the amount to be given. A horn or tin bottle may be better, because it is not so easily broken by the teeth. If the dose is a small one the horse's head may be held up by the left hand, while the medicine is poured into the mouth by the right. The left thumb is to be placed in the angle of the lower jaw, and the fingers spread out in such manner as to support the lower lip. Should the dose be large, the horse ugly, or the attendant unable to support the head as directed above, the head is then to be held up by running the tines of a long-handled wooden fork under the noseband of the halter or the halter strap or a rope may be fastened to the noseband and thrown over a limb, beam, or through a pulley suspended from the ceiling. Another way of supporting the head is to place a loop in the end of a rope, and introduce this loop into the mouth just behind the upper front teeth or tusks of the upper jaw, the free end to be run through a pulley, as before described, and held by an assistant. It is never to be fastened, as the horse might in that case do himself serious injury. The head is to be elevated just enough to prevent the horse from throwing the liquid out of his mouth. The line of the face should be horizontal, or only the least bit higher. If the head is drawn too high the animal can not swallow with ease or even with safety. (If this is doubted, just fill your mouth with water, throw-back the head as far as possible, and then try to swallow.) The person giving the drench should stand on some object in order to reach the horse's mouth on a level, or a little above it. The bottle or horn is then to be introduced at the side of the mouth, in front of the molar teeth, in an upward direction. This will cause the horse to open his mouth, when the base of the bottle is to be elevated, and about 4 ounces of the liquid allowed to escape on the tongue as far back as possible, care being taken not to get the neck of the bottle between the back teeth. The bottle is to be immediately removed, and if the horse does not swallow this can be encouraged by rubbing the fingers or neck of the bottle against the roof of the mouth, occasionally removing them. As soon as this is swallowed repeat the operation until he has taken all the drench. If coughing occurs, or if, by any mishap, the bottle should be crushed in the mouth, lower the head immediately.
Liquids. It is, very often, impossible to get balls properly made, or to induce owners or attendants to attempt to give them, and for these reasons medicines by the mouth are mostly given in the form of liquids. Liquids may be given as drenches when the dose is large, or they may, when but a small quantity is administered, be injected into the mouth with a hard-rubber syringe or be poured upon the tongue from a small vial.
Pastes or electuaries are medicines mixed with licorice-root powder, ground flaxseed, molasses, or sirup to the consistency of honey, or a "soft solid." They are intended, chiefly, to act locally upon the mouth and throat. They are given by being spread upon the tongue, gums, or teeth with a wooden paddle or strong, long-handled spoon.
When balls are to be given we should observe the following directions: In shape they should be cylindrical, of the size above mentioned, and soft enough to be easily compressed by the fingers. If made round or egg-shaped, if too long or too hard, they are liable to become fixed in the gullet and cause choking. Balls may be given with the "balling gun" (obtainable at any veterinary instrument maker's) or by the hand. If given by the hand a mouth speculum or gag may be used to prevent the animal from biting the hand or crushing the ball. Always loosen the horse before attempting to give a ball; if tied he may break his halter and injure himself or the one giving the ball. With a little practice it is much easier to give a ball without the mouth gag, as the horse always fights more or less against having his mouth forced open. The tongue must be firmly grasped with the left hand and gently pulled forward; the ball, slightly moistened, is then to be placed with the tips of the fingers of the right hand as far back into the mouth as possible; as the tongue is loosened it is drawn back into the mouth and carries the ball backward with it. The mouth should be kept closed for a minute or two. We should always have a pail of water at hand to offer the horse after balling. This precaution will often prevent him from coughing out the ball or its becoming lodged in the gullet.
Pills, or "balls" when properly made, are cylindrical in shape, 2 inches in length and about three-fourths of an inch in diameter. They should be fresh, but if necessary to keep them some time they should be made up with glycerin, or some such agent, to prevent their becoming too hard. Very old, hard balls are sometimes passed whole with the manure without being acted upon at all. Paper is sometimes wrapped around balls when given, if they are so sticky as to adhere to the fingers or the balling gun. Paper used for this purpose should be thin but firm, as the tougher tissue papers. Balls are preferred to drenches when the medicine is extremely disagreeable or nauseating; when the dose is not too large; when the horse is difficult to drench; or when the medicine is intended to act slowly. Certain medicines can not or should not be made into balls, as medicines requiring to be given in large doses, oils, caustic substances, unless in small dose and diluted and thoroughly mixed with the vehicle, deliquescent, or efflorescent salts. Substances suitable for balls can be made up by the addition of honey, sirup, soap, etc., when required for immediate use. Gelatin capsules of different sizes are now obtainable and are a convenient means of giving medicines in ball form.
Powders. Solids administered as powders should be as finely pulverized as possible, in order to obtain rapid solution and absorption. Their action is in this way facilitated and intensified. Powders must be free from any irritant or caustic action upon the mouth. Those that are without any disagreeable taste or smell are readily eaten with the feed or taken in the drinking water. When placed with the feed they should first be dissolved or suspended in water and thus sprinkled on the feed. If mixed dry the horse will often leave the medicine in the bottom of his manger. Nonirritant powders may be given in capsules, as balls are given.
Medicine may enter the body through any of the following designated channels: First, by the mouth; second, by the air passages; third, by the skin; fourth, by the tissue beneath the skin (hypodermic methods); fifth, by the rectum; sixth, by the genito-urinary passages; and, seventh, by the blood (intravenous injections).
By the mouth. Medicines can be given by the mouth in the form of solids, as powders or pills; liquids, and pastes, or electuaries.
When the irritation which is the cause of fever is a specific one, either in the form of bacteria (living organisms), as in glanders, tuberculosis, influenza, septicemia, etc., or in the form of a foreign element, as in rheumatism, gout, hemaglobinuria, and other so-called diseases of nutrition, we employ remedies which have been found to have a direct specific action on them. Among the specific remedies for various diseases are counted quinin, carbolic acid, salicylic acid, antipyrene, mercury, iodin, the empyreumatic oils, tars, resins, aromatics, sulphur, and a host of other drugs, some of which are of known effect and others of which are theoretical in action. Certain remedies, like simple aromatic teas, vegetable acids, such as vinegar, lemon juice, etc., alkalines in the form of salts, sweet spirits of niter, etc., which are household remedies, are always useful, because they act on the excreting organs and ameliorate the effects of fever. Other remedies, which are to be used to influence the cause of fever, must be selected with judgment and from a thorough knowledge of the nature of the disease.
The treatment of fever depends upon its cause. One of the important factors in treatment is absolute quiet. This may be obtained by placing a sick horse in a box stall, away from other animals and extraneous noises and sheltered from excessive light and drafts of air. Anodynes, belladonna, hyoscyamus, and opium act as antipyretics simply by quieting the nervous system. As an irritant exists in the blood in most cases of fever, any remedy which will favor the excretion of foreign elements from it will diminish this cause. We therefore use diaphoretics to stimulate the sweat and excretions from the skin; diuretics to favor the elimination of matter by the kidneys; cholagogues and laxatives to increase the action of the liver and intestines, and to drain from these important organs all the waste material which is aiding to choke up and congest their rich plexuses of blood vessels. The heart becomes stimulated to increased action at the outset of a fever, but this does not indicate increased strength; on the contrary, it indicates the action of an irritant to the heart that will soon weaken it. It is, therefore, irrational further to depress the heart by the use of such drugs as aconite. It is better to strengthen it and to favor the elimination of the substance that is irritating it. The increased blood pressure throughout the body may be diminished by lessening the quantity of blood. This is obtained in some cases with advantage when the disease is but starting and the animal is plethoric by direct abstraction of blood, as in bleeding from the jugular or other veins; or by derivatives, such as mustard, turpentine, or blisters applied to the skin; or by setons, which draw to the surface the fluid of the blood, thereby lessening its volume without having the disadvantage of impoverishing the elements of the blood found in bleeding. In many cases antipyretics given by the mouth and cold applied to the skin are most useful.
Fever, with its symptoms of increased temperature, acceleration of the pulse, acceleration of respiration, dry skin, diminished secretions, etc., must be considered as an indication of organic disturbance. This organic disturbance may be the result of local inflammation or other irritants acting through the nerves on nerve centers, alterations of the blood, in which a poison is carried to the nerve centers, or direct irritants to the nerve centers themselves, as in cases of heat stroke, injury to the brain, etc.
Any animal suffering from fever, whatever the cause, is much more susceptible to attacks of local inflammation, which become complications of the original disease, than are animals in sound health. In fever we have the tissues and the walls of the blood vessels weakened, we have an increased current of more or less altered blood flowing through the vessels and stagnating in the capillaries, which need but an exciting cause to transform the passive congestion of fever into an active congestion and acute inflammation. These conditions become still more distinct when the fever is accompanied with a decided deterioration in the blood itself, as is seen in influenza, septicemia, and at the termination of severe pneumonias.
In specific cases, such as influenza, strangles, and septicemia, there is a definite poison in the blood-vessel system and carried to the heart and to the nervous system, which produces a peculiar irritation, usually lasting for a specific period, during which the temperature can be but slightly diminished by any remedy.
In cases attended with complications, the diagnosis at times becomes still more difficult, as at the end of a case of influenza which becomes complicated with pneumonia. The high temperature of the simple inflammatory disease may be grafted on that of the specific trouble, and the determination of the cause of the fever, as between the two, is therefore frequently a difficult matter but an important one, as upon it depends the mode of treatment.
While the ears, cannons, and hoofs of a horse suffering from fever are usually found hot, they may frequently alternate from hot to cold, or be much cooler than they normally are. This latter condition usually indicates great weakness on the part of the circulatory system.
It is of the greatest importance, as an aid in diagnosing the gravity of an attack of fever and as an indication in the selection of its mode of treatment, to recognize the exact cause of a febrile condition in the horse. In certain cases, in very nervous animals, in which fever is the result of nerve influence, a simple anodyne, or even only quiet with continued care and nursing, will sometimes be sufficient to diminish it. When fever is the result of local injury, the cure of the cause produces a cessation in the constitutional symptoms. When it is the result of a pneumonia or other severe parenchymatous inflammation, it usually lasts for a definite time, and subsides with the first improvement of the local trouble, but in these cases we constantly have exacerbations of fever due to secondary inflammatory processes, such as the formation of small abscesses, the development of secondary bronchitis, or the death of a limited quantity of tissue (gangrene).
The excretion from the kidneys is sometimes at first entirely suppressed. It is always considerably diminished, and what urine is passed is dark in color, undergoes ammoniacal change rapidly, and deposits quantities of salts. At a later period the diminished excretion may be replaced by an excessive excretion, which aids in carrying off waste products and usually indicates an amelioration of the fever.
The normal body temperature, which varies from 99° to 100° F., is elevated from 1° to 9°. A temperature of 102° or 103° F. is moderate fever, 104° to 105° F. is high, and 106° F. and over is excessive. The temperature is accurately measured by means of a clinical thermometer inserted in the rectum.
This elevation of temperature can readily be felt by the hand placed in the mouth of the animal, or in the rectum, and in the cleft between the hind legs. It is usually appreciable at any point over the surface of the body and in the expired air emitted from the nostrils. The ears and cannons are often as hot as the rest of the body, but are sometimes cold, which denotes a debility in the circulation and irregular distribution of the blood. The pulse, which in a healthy horse is felt beating about 42 to 48 times in the minute, is increased to 60, 70, 90, or even 100. The respirations are increased from 14 or 16 to 24, 30, 36, or even more. With the commencement of a fever the horse usually has diminished appetite, or it may have total loss of appetite if the fever is excessive. There is, however, a vast difference among horses in this regard. With the same degree of elevation of temperature one horse may lose its appetite entirely, while another, usually of the more common sort, will eat at hay throughout the course of the fever, and will even continue to eat oats or other grains. Thirst is usually increased, but the animal desires only a small quantity of water at a time, and in most cases of fever a bucket of water should be kept standing before the patient, which may be allowed to drink ad libitum. The skin becomes dry and the hairs stand on end. Sweating is almost unknown in the early stage of fevers, but frequently occurs later in their course, when an outbreak of warm sweat is often a most favorable symptom. The mucous membranes, which are most easily examined in the conjunctivae of the eyes and inside of the mouth, change color if the fever is an acute one; without alteration of blood the mucous membranes become of a rosy or deep-red color at the outset; if the fever is attended with distinct alteration of the blood, as in influenza, and at the end of two or three days in severe cases of pneumonia or other extensive inflammatory troubles the mucous membranes are tinged with yellow, which may even become a deep ocher in color, the result of the decomposition of the blood corpuscles and the freeing of their coloring matter, which acts as a stain. At the outset of a fever the various glands are checked in their secretions, the salivary glands fail to secrete the saliva, and we find the surface of the tongue and inside of the cheeks dry and covered with a brownish, bad-smelling deposit. The excretion from the liver and intestinal glands is diminished and produces an inactivity of the digestive organs which causes a constipation. If this is not remedied at an early period, the undigested material acts as an irritant, and later we may have it followed by an inflammatory process, producing a severe diarrhea.
Fever in all animals is characterized by the same general phenomena, but we find the intensity of the symptoms modified by the species of animals affected, by the races which subdivide the species, by the families which form groups of the races, and by certain conditions in individuals themselves. For example, a pricked foot in a Thoroughbred may cause intense fever, while the same injury in the foot of a Clydesdale may scarcely cause a visible general symptom. In the horse, fever produces the following symptoms:
There are times when it is difficult to distinguish between the existence of fever as a disease and a temporary feverish condition which is the result of excessive work. Like the condition of congestion of the lungs, which is normal up to a certain degree in the lungs of a race horse after a severe race, and morbid when it produces more than temporary phenomena or when it causes distinct lesions, the temperature may rise from physiological causes as much as four degrees, so fever, or, as it is better termed, a feverish condition, may follow any work or other employment of energy in which excessive tissue change has taken place; but if the consequences are ephemeral, and no recognizable lesion is apparent, it is not considered morbid. This condition, however, may predispose to severe organic disturbance and local inflammations which will cause disease, as an animal in this condition is liable to take cold and develop lung fever or a severe enteritis, if chilled or otherwise exposed.
There is in fever at first a relaxation of the small blood vessels, which may have been preceded by a contraction of the same if there was a chill, and as a consequence there is an acceleration of the current of the blood. There is, then, an elevation of the peripheral temperature, followed by a lowering of tension in the arteries and an acceleration in the movement of the heart. These conditions may be produced by a primary irritation of the nerve centers of the brain from the effects of heat, as is seen in thermic fever, or sunstroke, or by the entrance into the blood stream of disease-producing organisms or their chemical products, as in anthrax, rinderpest, influenza, etc.
Whether the cause of the fever has been an injury to the tissues, such as a severe bruise, a broken bone, an inflamed lung, or excessive work, which has surcharged the blood with the waste products of the combustion of the tissues, which were destroyed to produce force, or the toxins of influenza in the blood, or the presence of irritating material, either in the form of living organisms or of their products, as in glanders or tuberculosis the general train of symptoms are much the same, varying as the amount of the irritant differs in quantity, or when some special quality in them has a specific action on one or another tissue.
Essential fevers are subdivided into ephemeral fevers, which last but a short time and terminate by critical phenomena; intermittent fevers, in which there are alterations of exacerbations of the febrile symptoms and remissions, in which the body returns to its normal condition or sometimes to a depressed condition, in which the functions of life are but badly performed; and continued fevers, which include contagious diseases, such as glanders, influenza, etc., the septic diseases, such as pyemia, septicemia, etc., and the eruptive fevers, such as variola, etc.
Fevers are divided into essential fevers and symptomatic fevers. In symptomatic fever some local disease, usually of an inflammatory character, develops first, and the constitutional febrile phenomena are the result of the primary point of combustion irritating the whole body, either through the nervous system or directly by means of the waste material which is carried into the circulation and through the blood vessels, and is distributed to distal parts. Essential fevers are those in which there is from the outset a general disturbance of the whole economy. This may consist of an elementary alteration in the blood or a general change in the constitution of the tissues. Fevers of the latter class are usually due to some infecting agent and belong, therefore, to the class of infectious diseases.
Fever is a general condition of the animal body in which there is an elevation of the animal body temperature, which may be only a degree or two or may be 10° F. The elevation of the body temperature, which represents tissue change or combustion, is accompanied with an acceleration of the heart's action, a quickening of the respiration, and an aberration in the functional activity of the various organs of the body. These organs may be stimulated to the performance of excessive work, or they may be incapacitated from carrying out their allotted tasks, or, in the course of a fever, the two conditions may both exist, the one succeeding the other. Fever as a disease is usually preceded by chills as an essential symptom.
Depressants are drugs which act on the heart. They slow or weaken the action of this organ and reduce the quantity and force of the current of the blood which is carried to the point of local disease; they lessen the vitality of the animal, and for this reason are now used much less than formerly.
Anodynes quiet the nervous system. Pain in the horse, as in the man, is one of the important factors in the production of fever, and the dulling of the former often prevents, or at least reduces, the latter. Anodynes produce sleep, so as to rest the patient and allow recuperation for the succeeding struggle of the vitality of the animal against the exhausting drain of the disease.
The diet of an animal suffering from acute inflammation is a factor of the greatest importance. An overloaded circulation can be starved to a reduced quantity and to a less rich quality of blood by reducing the quantity of feed given to the patient. Feeds of easy digestion do not tire the already fatigued organs of an animal with a torpid digestive system. Nourishment will be taken by a suffering brute in the form of slops and cooling drinks when it would be totally refused if offered in its ordinary form, as hard oats or dry hay, requiring the labor of grinding between the teeth and swallowing by the weakened muscles of the jaws and throat.
Tonics and stimulants are remedies which are used to meet special indications, as in the case of a feeble heart, and which enter into the after treatment of inflammatory troubles as well as into the acute stages of them. They brace up weakened and torpid glands; they stimulate the secretion of the necessary fluids of the body, and hasten the excretion of the waste material produced by the inflammatory process; they regulate the action of a weakened heart; they promote healthy vitality of diseased parts, and aid the chemical changes needed for returning the altered tissues to their normal condition.
Cathartics act by drawing off a large quantity of fluid from the blood through the intestines, and have the advantage over the last remedy of removing only the watery and not the formed elements from the circulation. The blood cells remain, leaving the blood as rich as it was before. Again, the glands of the intestines are stimulated to excrete much waste matter and other deleterious material which may be acting as a poison in the blood.
Diuretics operate through the kidneys in the same way.
Diaphoretics aid depletion of the blood by pouring water in the form of sweat from the surface of the skin and stimulating the discharge of waste material out of its glands, which has the same effect on the blood pressure.
Antipyretics are remedies to reduce the temperature. This may be accomplished by depressing the center in the brain that controls heat production. Some coal-tar products are very effective in this way, but they have the disadvantage of depressing the heart, which should always be kept as strong as possible. If they are used it must be with knowledge of this fact, and it is well to give heart tonics or stimulants with them. The temperature of the body may be lowered by cold packs or by showering with cold water. This is a most useful procedure in many diseases.
Counterirritants are used for deep inflammations. They act by bringing the blood to the surface and consequently lessening the blood pressure within. The derivation of the blood to the exterior diminishes the amount in the internal organs and is often very rapid in its action in relieving a congested lung or liver. The most common counterirritant is mustard flour. It is applied as a soft paste mixed with warm water to the under surface of the belly and to the sides, where the skin is comparatively soft and vascular. Colds in the throat or inflammations at any point demand the treatment applied in the same manner to the belly and sides and not to the throat or on the legs, as so often used. Blisters, iodin, and many other irritants are used in a similar way.
Constitutional treatment in inflammation is designed to reduce the current of blood, which is the fuel for the inflammation in the diseased part, to quiet the patient, and to combat the fever or general effects of the trouble in the system, and to favor the neutralization or elimination of the products of the inflammation.
Reduction of blood is obtained in various ways. The diminution of the quantity of the blood lessens the amount of pressure on the vessels, and, as a sequel, the volume of it which is carried to the point of inflammation; it diminishes the body temperature or fever; it numbs the nervous system, which plays an important part as a conductor of irritation in diseases.
Blood-letting is the most rapid means, and frequently acts like a charm in relieving a commencing inflammatory trouble. One must remember, however, that the strength of the body and repair depend on the blood; hence blood-letting should be practiced only in full-blooded, well-nourished animals and in the early stages of the disease.
Motion stimulates the action of the blood, and thus feeds an inflamed tissue. This is alike applicable to a diseased point irritated by movement to an inflamed pair of lungs surcharged with blood by the use demanded of them in a working animal, or to an inflamed eye exposed to light, or an inflamed stomach and intestines still further fatigued by feed. Rest, absolute quiet, a dark stable, and small quantities of easily digested feed will often cure serious inflammatory troubles without further treatment.
The application of ice bags or cold water by bandages, douching with a hose, or irrigation with dripping water, contracts the blood vessels, acts as a sedative to the nerves, and lessens the vitality of a part; it consequently prevents the tissue change which inflammation produces.
Either dry or moist heat acts as a derivative. It quickens the circulation and renders the chemical changes more active in the surrounding parts; it softens the tissues and attracts the current of blood from the inflamed organ; it also promotes the absorption of the effusion and hastens the elimination of the waste products in the part. Heat may be applied by hand rubbing or active friction and the application of warm coverings (bandages) or by cloths wrung out of warm water; or steaming with warm, moist vapor, medicated or not, will answer the same purpose. The latter is especially applicable to inflammatory troubles in the air passages.
Local bleeding frequently affords immediate relief by carrying off the excessive blood and draining the effusion which has already occurred. It affords direct mechanical relief, and, by a stimulation of the part, promotes the chemical changes necessary for bringing the diseased tissues to a healthy condition. Local blood-letting can be done by scarifying, or making small punctures into the inflamed part, as in the eyelid of an inflamed eye, or into the sheath of the penis, or into the skin of the latter organ when congested, or the leg when acutely swelled.
Treatment of inflammation. The study of the causes and pathological alterations of inflammation has shown the process to be one of hypernutrition, attended by excessive blood supply, so this study will indicate the primary factor to be employed in the treatment of it. Any agent which will reduce the blood supply and prevent the excessive nutrition of the elements of the part will serve as a remedy. The means employed may be used locally to the part, or they may be constitutional remedies, which act indirectly.
Local treatment. Removal of the cause will frequently allow the part to heal at once. Among causes of inflammation may be mentioned a stone in the frog, causing a traumatic thrush; a badly fitting harness or saddle, causing ulcers of the skin; decomposing manure and urine in a stable, which, by their vapors, irritate the air tubes and lungs and cause a cough.
Termination of inflammation. Like congestion, inflammation may terminate by resolution. In this case the exuded lymph undergoes chemical change, and the products are absorbed and carried off by the blood vessels and lymphatics, to be thrown out of the body by the kidneys, liver, the glands of the skin, and the other excretory organs. The cells, which have wandered into the neighboring tissues from the blood vessels, gradually disappear or become transformed into fixed cells. Those which are the result of the tissue cells, wakened into active life, follow the same course. The vessels themselves contract, and, having resumed their normal caliber, the part apparently reassumes its normal condition; but it is always weakened, and a new inflammation is more liable to reappear in a previously inflamed part than in a sound one. The alternate termination is necrosis, or mortification. If the necrosis, or death of a part, is gradual, by small stages, each cell losing its vitality after the other in more or less rapid succession, it takes the name of ulceration. If it occurs in a considerable part at once, it is called gangrene. If this death of the tissues occurs deep in the organism, and the destroyed elements and proliferated and dead cells are inclosed in a cavity, the result of the process is called an abscess. When it occurs on a surface, it is an ulcer, and an abscess by breaking on the exterior becomes then also an ulcer. Proliferating and dying cells, and the fluid which exudes from an ulcerating surface and the débris of broken-down tissue is known as pus, and the process by which this is formed is known as suppuration. A mass of dead tissue in a soft part is termed a slough, while the same in bone is called a sequestrum. Such changes are especially liable to occur when the part becomes infected with microorganisms that have the property of destroying tissue and thus causing the production of pus. These are known as pyogenic microorganisms. There are also bacilli that are capable of multiplying in tissues and so irritating them as to cause them to die (necrose) without forming pus.
Whether the inflamed tissue is one like the skin, lungs, or intestines, very loose in their texture, or a tendon or bone, dense in structure, and comparatively poor in blood vessels, the principle of the process is the same. The effects, however, and the appearance may be widely different. After a cut on the face or an exudation into the lungs, the loose tissues and multiple vessels allow the proliferating cells to obtain rich nourishment; absorption can take place readily, and the part regains its normal condition entirely, while a bruise at the heel or at the withers finds a dense, inextensible tissue where the multiplying elements and exuded fluids choke up all communication, and the parts die (necrose) from want of blood and cause a serious quittor, or fistula.
This effect of structure of a part on the same process shows the importance of a perfect knowledge in the study of a local trouble, and the indispensable part which such knowledge plays in judging of the gravity of an inflammatory disease, and in formulating a prognosis or opinion of the final termination of it. It is this which allows the veterinarian, through his knowledge of the intimate structure of a part and the relations of its elements, to judge of the severity of a disease, and to prescribe different modes of treatment in two animals for troubles which, to the less experienced observer, appear to be absolutely identical.
The alterations in an inflamed tissue are first those of congestion, distention of the blood vessels, and exudation of the fluid of the blood into the surrounding fibers, with, however, a more nearly complete stagnation of the blood; fibrin, or lymph, a plastic substance, is thrown out as well, and the cells, which we have seen to be living organisms in themselves, no longer carried in the current of the blood, migrate from the vessels and, finding proper nutriment, proliferate or multiply with greater or lesser rapidity. The cells which lie dormant in the meshes of the surrounding fibers are awakened into activity by the nutritious lymph which surrounds them, and they also multiply.
Whether the cell in an inflamed part is the white ameboid cell of the blood or the fixed connective tissue embedded in the fibers, it multiplies in the same way. The nucleus in the center is divided into two, and then each again into two, ad infinitum. If the process is slow, each new cell may assimilate nourishment and become, like its ancestor, an aid in the formation of new tissues; if, however, the changing takes place rapidly, the brood of young cells have not time to grow or use up the surrounding nourishment, and, but half developed, they die, and we then have destruction of tissue, and pus or matter is formed, a material made up of the imperfect dead elements and the broken-down tissue. Between the two there is an intermediate form, where we have imperfectly formed tissues, as in "proud flesh," large, soft splints; fungous growths, greasy heels, and thrush.
Inflammations of the internal organs are caused by irritants as above, and by sudden cooling of the surface of the animal, which drives the blood to that organ which at the moment is most actively supplied with blood. This is called repercussion. A horse which has been worked at speed and is breathing rapidly is liable to have pneumonia if suddenly chilled, while an animal which has just been fed is more liable to have a congestive colic if exposed to the same influence, the blood in this case being driven from the exterior to the intestines, while in the former it was driven to the lungs.
Symptoms. The symptoms of inflammation are, as in congestion, change of color, due to an increased supply of blood; swelling, from the same cause, with the addition of an effusion into the surrounding tissues; heat, owing to the increased combustion in the part; pain, due to pressure on the nerves, and altered function. This latter may be augmented or diminished, or first one and then the other. In addition to the local symptoms, inflammation always produces more or less constitutional disturbance or fever. A splint or small spavin will cause so little fever that it is not appreciable, while a severe spavin, an inflamed joint, or a pneumonia may give rise to a marked fever.
Young horses have inflammation of the membranes lining the air passages and digestive tract, while older animals are more subject to troubles in the closed serous sacs and in the bones.
The work to which a horse is put (saddle or harness, speed or draft) will influence the predisposition of an animal to inflammatory diseases. As in congestion, the functional activity of a part is an important factor in localizing this form of disease. Given a group of horses exposed to the same draft of cold air or other exciting cause of inflammation, the one which has just been eating will be attacked with an inflammation of the bowels; the one that has just been working so as to increase its respiration will have an inflammation of the throat, bronchi, or lungs; the one that has just been using its feet excessively will have a founder or inflammation of the laminae of the feet.
The direct cause of inflammation is usually an irritant of some form. This may be a pathogenic organism a disease germ or it may be mechanical or chemical, external or internal. Cuts, bruises, injuries of any kind, parasites, acids, blisters, heat, cold, secretions, such as an excess of tears over the cheek or urine on the legs, all cause inflammation by direct injury to the part. Strains or wrenches of joints, ligaments, and tendons cause trouble by laceration of the tissue.
The temperament of a horse predisposes the animal to inflammation of certain organs. A full-blooded animal, whose veins show on the surface of the body, and which has a strong, bounding heart pumping large quantities of blood into the vascular organs like the lungs, the intestines, and the laminae of the feet, is more liable to have pneumonia, congestive colics, and founder, than lymphatic, cold-blooded animals which have pleurisies, inflammation of the bones, spavins, ringbones, inflammation of the glands of the less vascular skin of the extremities, greasy heels, thrush, etc.
