Chapter 13

The tube should be removed once a day and cleaned with carbolic-acid solution (1 to 20), and the discharge washed away from the wound with a solution of carbolic acid, 1 part to 40 parts water. Several times a day the hand should be held over the opening in the tube to test the animal's ability to breathe through the nostrils, and as soon as it is demonstrated that breathing can be performed in the natural way the tube should be removed, the wound thoroughly cleansed with carbolic-acid solution (1 to 40), and closed by inserting four or five stitches through the skin and muscle. Do not include the cartilages of the windpipe in the stitches. Apply the solution to the wound three or four times a day until healed. When the tube is removed to clean it the lips of the wound may be pressed together to ascertain whether or not the horse can breathe through the larynx. The use of the tube should be discontinued as soon as possible.

It is true that tracheotomy tubes are seldom to be found on farms, and especially when most urgently required. In such instances there is nothing left to be done but, with a strong needle, pass a waxed end or other strong string through each side of the wound, including the cartilage of the windpipe, and keep the wound open by tying the strings over the neck.

During the time the tube is used the other treatment advised must not be neglected. After a few days the discharge from the nostrils becomes thicker and more profuse. This is a good symptom and signifies that the acute stage has passed. At any time during the attack, if the horse becomes weak, give whisky or aromatic spirits of ammonia, 2 ounces in water. Do not be in a hurry to put the animal back to work, but give plenty of time for a complete recovery. Gentle and gradually increasing exercise may be given as soon as the horse is able to stand it. The feed should be carefully selected and of good quality. Tonics, as iron or arsenic, may be employed.

If abscesses form in connection with the disease they must be opened to allow the escape of pus, but do not rashly plunge a knife into swollen glands; wait until you are certain the swelling contains pus. The formation of pus may be encouraged by the constant application of poultices for hours at a time. The best poultice for the purpose is made of linseed meal, with sufficient hot water to make a thick paste. If the glands remain swollen for some time after the attack, rub well over them an application of the following: Biniodid of mercury, 1 dram; lard, 1 ounce; mix well. This may be applied once every day until the part is blistered.

Sore throat is also a symptom of other diseases, such as influenza, strangles, purpura hemorrhagica, etc., which diseases may be consulted under their proper headings.

After a severe attack of inflammation of the larynx the mucous membrane may be left in a thickened condition, or an ulceration of the part may ensue, either of which is liable to produce a chronic cough. For the ulceration it is useless to prescribe, because it can neither be diagnosed nor topically treated by the nonprofessional.

If a chronic cough remains after all the other symptoms have disappeared, it is advisable to give 1 dram of iodid of potassium dissolved in a bucketful of drinking water, one hour before feeding, three times a day for a month if necessary. Also rub in well the preparation of iodid of mercury (as advised for the swollen glands) about the throat, from ear to ear, and in the space between the lower jawbones. The application may be repeated every third day until the part is blistered.

SPASM OF THE LARYNX.

The symptoms are as follows: Sudden seizure by a violent fit of coughing; the horse may reel and fall, and after a few minutes recover and be as well as ever. The treatment recommended is this: Three drams of bromid of potassium three times a day, dissolved in the drinking water, or give as a drench in about a half pint of water for a week. Then give 1 dram of powdered nux vomica (either on the food or shaken with water as a drench) once a day for a few weeks.

CROUP AND DIPHTHERIA.

Neither of these diseases affects the horse, but these names are sometimes wrongly applied to severe laryngitis or pharyngitis, or to forage poisoning, in which the throat is paralyzed and becomes excessively inflamed and gangrenous.

THICK WIND AND ROARING.

Horses that are affected with chronic disease that causes a loud, unnatural noise in breathing are said to have thick wind, or to be roarers. This class does not include those affected with severe sore throat, as in these cases the breathing is noisy only during the attack of the acute disease.

Thick wind is caused by an obstruction to the free passage of the air in some part of the respiratory tract. Nasal polypi, thickening of the membrane, pharyngeal polypi, deformed bones, paralysis of the wing of the nostril, etc., are occasional causes. The noisy breathing of horses after having been idle and put to sudden exertion is not due to any disease and is only temporary. Very often a nervous, excitable horse will make a noise for a short time when started off, generally caused by the cramped position in which the head and neck are forced in order to hold him back.

Many other causes may occasion temporary, intermittent, or permanent noisy respiration, but chronic roaring is caused by paralysis of the muscles of the larynx; and almost invariably it is the muscles of the left side of the larynx that are affected.

In chronic roaring the noise is made when the air is drawn into the lungs; only when the disease is far advanced is a sound produced when the air is expelled, and even then it is not nearly so loud as during inspiration.

In a normal condition the muscles dilate the aperture of the larynx by moving the cartilage and vocal cord outward, allowing a sufficient volume of air to rush through. But when the muscles are paralyzed the cartilage and vocal cord that are normally controlled by the affected muscles lean into the tube of the larynx, so that when the air rushes in it meets this obstruction and the noise is produced. When the air is expelled from the lungs its very force pushes the cartilage and vocal cords out, and consequently noise is not produced in the expiratory act.

The paralysis of the muscles is due to derangement of the nerve that supplies them with energy. The muscles of both sides are not supplied by the same nerve; there is a right and a left nerve, each supplying its respective side. The reason why the muscles on the left side are the ones usually paralyzed is owing to the difference in the anatomical arrangement of the nerves. The left nerve is much longer and more exposed to interference than the right nerve.

In chronic roaring there is no evidence of any disease of the larynx other than the wasted condition of the muscles in question. The disease of the nerve is generally far from the larynx. Disease of parts contiguous to the nerve along any part of its course may interfere with its proper function. Enlargement of lymphatic glands within the chest through which the nerve passes on its way back to the larynx is the most frequent interruption of nervous supply, and consequently roaring. When roaring becomes confirmed, medical treatment is entirely useless, as it is impossible to restore the wasted muscle and at the same time remove the cause of the interruption of the nervous supply. Before roaring becomes permanent the condition may be benefited by a course of iodid of potassium, if caused by disease of the lymphatic glands. Electricity has been used with indifferent success. Blistering or firing over the larynx is, of course, not worthy of trial if the disease is due to interference of the nerve supply. The administration of strychnia (nux vomica) on the ground that it is a nerve tonic with the view of stimulating the affected muscles is treating only the result of the disease without considering the cause, and is therefore useless. The operation of extirpating the collapsed cartilage and vocal cord is believed to be the only relief, and, as this operation is critical and can be performed only by the skillful veterinarian, it will not be described here.

From the foregoing description of the disease it will be seen that the name "roaring," by which the disease is generally known, is only a symptom and not the disease. Chronic roaring is also in many cases accompanied with a cough. The best way to test whether a horse is a "roarer" is either to make him pull a load rapidly up a hill or over a sandy road or soft ground; or, if he is a saddle horse, gallop him up a hill or over soft ground. The object is to make him exert himself. Some horses require a great deal more exertion than others before the characteristic sound is emitted. The greater the distance he is forced, the more he will appear exhausted if he is a roarer; in bad cases the animal becomes utterly exhausted, the breathing is rapid and difficult, the nostrils dilate to the fullest extent, and the animal appears as if suffocation was imminent.

An animal that is a roarer should not be used for breeding purposes. The taint is transmissible in many instances.

_Grunting._--A common test used by veterinarians when examining "the wind" of a horse is to see if he is a "grunter." This is a sound emitted during expiration when the animal is suddenly moved, or startled, or struck at. If he grunts he is further tested for roaring. Grunters are not always roarers, but, as it is a common thing for a roarer to grunt, such an animal must be looked upon with suspicion until he is thoroughly tried by pulling a load or galloped up a hill. The test should be a severe one. Horses suffering with pleurisy, pleurodynia, or rheumatism, and other affections accompanied with much pain, will grunt when moved, or when the pain is aggravated, but grunting under these circumstances does not justify the term of "grunter" being applied to the horse, as the grunting ceases when the animal recovers from the disease that causes the pain.

_High blowing._--This term is applied to a noisy breathing made by some horses. It is distinctly a nasal sound, and must not be confounded with "roaring." The sound is produced by the action of the nostrils. It is a habit and not an unsoundness. Contrary to roaring, when the animal is put to severe exertion the sound ceases. An animal that emits this sound is called a "high blower." Some horses have naturally very narrow nasal openings, and they may emit sounds louder than usual in their breathing when exercised.

_Whistling_ is only one of the variations of the sound emitted by a horse called a "roarer," and therefore needs no further notice, except to remind the reader that a whistling sound may be produced during an attack of severe sore throat or inflammation of the larynx, which passes away with the disease that causes it.

CHRONIC BRONCHITIS.

This may be due to the same causes as acute bronchitis or it may follow the latter disease. An attack of the chronic form is liable to be converted into acute bronchitis by a very slight cause. This chronic affection in most instances is associated with thickening of the walls of the tubes. Its course is slower, it is less severe, and is not accompanied with so much fever as the acute form. If the animal is exerted, the breathing becomes quickened and he soon shows signs of exhaustion. In many instances the animal keeps up strength and appearances moderately well, but in other cases the appetite is lost, flesh gradually disappears, and he becomes emaciated and debilitated. It is accompanied with a persistent cough, which in some cases is husky, smothered, or muffled, while in others it is hard and clear. A whitish matter, which may be curdled, is discharged from the nose. If the ear is placed against the chest behind the shoulder blade, the rattle of the air passing through the mucus can be heard within.

_Treatment._--Rest is necessary, as even under the most favorable circumstances a cure is difficult to effect. The animal can not stand exertion and should not be compelled to undergo it. It should have much the same general care and medical treatment prescribed for the acute form. Arsenious acid in tonic doses (3 to 7 grains) three times daily may be given. As arsenic is irritant, it must be mixed with a considerable bulk of moist feed and never given alone. Arsenic may be given in the form of Fowler's solution, 1 ounce three times daily in the drinking water. An application of mustard applied to the breast is a beneficial adjunct. The diet should be the most nourishing. Bulky feed should not be given. Linseed mashes, scalded oats, and, if in season, grass and green-blade fodder are the best diet.

THE LUNGS.

The lungs (see Pl. VII) are the essential organs of respiration. They consist of two (right and left) spongy masses, commonly called the "lights," situated entirely within the thoracic cavity. On account of the space taken up by the heart, the left lung is the smaller. Externally, they are completely covered by the pleura. The structure of the lung consists of a light, soft, but very strong and remarkably elastic tissue, which can be torn only with difficulty. Each lung is divided into a certain number of lobes, which are subdivided into numberless lobules (little lobes). A little bronchial tube terminates in every one of these lobules. The little tube then divides into minute branches which open into the air cells (pulmonary vesicles) of the lungs. The air cells are little sacs having a diameter varying from one-seventieth to one two-hundredth of an inch; they have but one opening, the communication with the branches of the little bronchial tubes. Small blood vessels ramify in the walls of the air cells. The air cells are the consummation of the intricate structures forming the respiratory apparatus. They are of prime importance, all the rest being complementary. It is here that the exchange of gases takes place. As before stated, the walls of the cells are very thin; so, also, are the walls of the blood vessels. Through these walls escapes from the blood the carbonic acid gas that has been absorbed by the blood in its circulation through the different parts of the body; through these walls also the oxygen gas, which is the life-giving element of the atmosphere, is absorbed by the blood from the air in the air cells.

CONGESTION OF THE LUNGS.

Congestion is essentially an excess of blood in the vessels of the parts affected. Congestion of the lungs in the horse, when it exists as an independent affection, is generally caused by overexertion when the animal is not in a fit condition to undergo more than moderate exercise. Very often what is recognized as congestion of the lungs is but a symptom of exhaustion or dilatation of the heart.

The methods practiced by the trainers of running and trotting horses will give an idea of what is termed "putting a horse in condition" to stand severe exertion. The animal at first gets walking exercises, then after some time he is made to go faster and farther each day; the amount of work is daily increased until he is said to be "in condition." An animal so prepared runs no risk of being affected with congestion of the lungs, if he is otherwise healthy. On the other hand, if the horse is kept in the stable for the purpose of laying on fat or for want of something to do, the muscular system becomes soft, and the horse is not in condition to stand the severe exertion of going fast or far, no matter how healthy he may be in other respects. If such a horse be given a hard ride or drive, he may start off in high spirits, but soon becomes exhausted, and if he is pushed he will slacken his pace, show a desire to stop, and may stagger or even fall. Examination will show the nostrils dilated, the flanks heaving, the countenance haggard, and the appearance of suffocation. The heart and muscles were not accustomed to the sudden and severe strain put upon them; the heart became unable to perform its work; the blood accumulated in the vessels of the lungs, which eventually became engorged with the stagnated blood, constituting congestion of the lungs.

The animal, after having undergone severe exertion, may not exhibit alarming symptoms until returned to the stable; then he will be noticed standing with his head down, legs spread out, the eyes wildly staring or dull and sunken. The breathing is very rapid and almost gasping; in most cases the body is covered with perspiration, which, however, may soon evaporate, leaving the surface of the body and the legs and ears cold; the breathing is both abdominal and thoracic; the chest rises and falls and the flanks are powerfully brought into action. If the pulse can be felt at all it will be found beating very frequently, one hundred or so to a minute. The heart may be felt tumultuously thumping if the hand is placed against the chest behind the left elbow, or it may be scarcely perceptible. The animal may tremble all over. If the ear is placed against the side of the chest a loud murmur will be heard and perhaps a fine, crackling sound.

One can scarcely fail to recognize a case of congestion of the lungs when brought on by overexertion, as the history of the case indicates the nature of the ailment. In all cases of suffocation the lungs are congested. It is also seen in connection with other diseases.

_Treatment._--If the animal is attacked by the disease while on the road, stop him immediately. Do not attempt to return to the stables. If he is in the stable, make arrangements at once to insure an unlimited supply of pure air. If the weather is warm, out in the open air is the best place, but if too cold let him stand with head to the door. Let him stand still; he has all he can do, if he obtains sufficient pure air to sustain life. If he is encumbered with harness or saddle, remove it at once and rub the body with cloths or wisps of hay or straw. This stimulates the circulation in the skin, and thus aids in relieving the lungs of the extra quantity of blood that is stagnated there. If you have three or four assistants, let them rub the body and legs well until the skin feels natural; rub the legs until they are warm, if possible. When the circulation is reestablished, put bandages on the legs from the hoofs up as far as possible. Throw a blanket over the body and let the rubbing be done under the blanket. Diffusible stimulants are the medicines indicated--brandy, whisky (or even ale or beer if nothing else is at hand), ether, and aromatic spirits of ammonia. A drench of 2 ounces each of spirits of nitrous ether and alcohol, diluted with a pint of water, every hour until relief is afforded, is among the best remedies. Or, give a quarter of a pint of whisky in a pint of water every hour, or the same quantity of brandy as often, or a quart of ale every hour, or 1 ounce of tincture of arnica in a pint of water every hour until five or six doses have been given. If none of these remedies are at hand, 2 ounces of oil of turpentine, shaken with a half pint of milk, may be given once, but not repeated. The animal may be bled from the jugular vein. Do not take more than 5 or 6 quarts from the vein, and do not repeat the bleeding. The blood thus drawn will have a tarry appearance.

When the alarming symptoms have subsided active measures may be stopped, but care must be used in the general treatment of the animal for several days, for it must be remembered that congestion may be followed by pneumonia. The animal should have a comfortable stall, where he will not be subjected to drafts or sudden changes of temperature; he should be blanketed and the legs kept bandaged. The air should be pure, a plentiful supply of fresh, cold water always in the stall; and a diet composed principally of bran mashes, scalded oats, and, if in season, grass. When ready for use again the horse should at first receive only moderate exercise, which may be daily increased until he may safely be put to regular work.

PNEUMONIA, OR LUNG FEVER.

Pneumonia is inflammation of the lungs. The chief varieties of pneumonia are catarrhal--later discussed in connection with bronchitis, under the name of broncho-pneumonia--and the fibrinous or croupous variety. The latter form receives its names from the fact that the air spaces are choked with coagulated fibrin thrown out from the blood. This causes the diseased portions of the lungs to become as firm as liver, in which condition they are said to be hepatized. As air is excluded by the inflammatory product, the diseased lung will not float in water.

The inflammation usually begins in the lower part of the lung and extends upward. The first stage of the disease consists of congestion, or engorgement, of the blood vessels, followed by leakage of serum containing fibrin from the blood vessels into the air passages. The fluids thus escaping into the air cells and in the minute branches of the little bronchial tubes become coagulated.

The pleura covering the affected parts may be more or less inflamed. A continuance of the foregoing phenomena is marked by a further escape of the constituents of the blood, and a change in the membrane of the cells, which becomes swollen. The exudate that fills the air cells and minute bronchial branches undergoes disintegration and softening when healing commences.

The favorable termination of pneumonia is in resolution that is, a restoration to health. This is gradually brought about by the exuded material contained in the air cells and lung tissues being broken down and softened and absorbed or expectorated through the nostrils. The blood vessels return to their natural state, and the blood circulates in them as before. In the cases that do not terminate so happily the lung may become gangrenous (or mortified), an abscess may form, or the disease may be merged into the chronic variety.

Pneumonia may be directly induced by any of the influences named as general causes for diseases of the organs of respiration, but in many instances it is from neglect. A common cold or sore throat may be followed by pneumonia if neglected or improperly treated. An animal may be debilitated by a cold, and when in this weakened state may be compelled to undergo exertion beyond his strength; or he may be kept in a badly ventilated stable, where the foul gases are shut in and the pure air is shut out; or the stable may be so open that parts of the body are exposed to drafts of cold air. An animal is predisposed to pneumonia when debilitated by any constitutional disease, and especially during convalescence if exposed to any of the exciting causes. Foreign bodies, such as feed accidentally getting into the lungs by way of the windpipe, as well as the inhalation of irritating gases and smoke, ofttimes produce fatal attacks of inflammation of the lung and bronchial tubes. Pneumonia is frequently seen in connection with other diseases, such as influenza, purpura hemorrhagica, strangles, glanders, etc. Pneumonia and pleurisy are most common during cold, damp weather, and especially during the prevalence of the cold north or northeasterly winds. Wounds puncturing the thoracic cavity may cause pneumonia.