It is not to be supposed that farmers can give their horses the particular attention given to valuable racing and pleasure horses, but they can most assuredly give them common-sense care, and this may often save the life of a valuable animal. If the owner properly considers his interests, he will study the welfare of his horses so that he may be able to instruct the servant in details of stable management.
Stables should be well drained and kept clean. Some farmers allow large quantities of manure to accumulate in the stable. This is a pernicious practice, as the decomposing organic matter evolves gases that are predisposing or exciting causes of disease. When a horse is overheated, it is not safe to allow him to dry by evaporation; rubbing him dry and gradually cooling him out is the wisest treatment. When a horse is hot covered with sweat it is dangerous to allow him to stand in a draft; it is the best plan to walk him until his temperature moderates. In such cases a light blanket thrown over the animal may prevent a cold. Overwork or overexertion often causes the greater number of fatal cases of congestion of the lungs. Avoid prolonged or fast work when the horse is out of condition or unaccustomed to it. Animals that have been working in cold rains should be dried and cooled out and not left to dry by evaporation. When the temperature of the weather is at the extreme, either of heat or cold, diseases of the organs of respiration are most frequent.
A cold, close stable is invariably damp, and is to be avoided as much as the hot, close, and foul one. Horses changed from a cold to a warm stable are more liable to contract cold than when changed from a warm to a cold one. Pure air is more essential than warmth, and this fact should be especially remembered when the stable is made close and foul to gain the warmth. It is more economical to keep the horse warm with blankets than to prevent the ingress of pure air in order to make the stable warm.
Badly ventilated stables are a frequent source of disease. It is a mistake to think that country stables necessarily have purer air than city stables. Stables on some farms are so faultily constructed that it is almost impossible for the foul air to gain an exit. All stables should have a sufficient supply of pure air, and be so arranged that strong drafts can not blow directly on the animals. In ventilating a stable, it is best to arrange to remove air from near the floor and admit it through numerous small openings near the ceiling. The reason for this is that the coldest and most impure air in the stable is near the floor, while that which is warmest and purest, and therefore can least be spared, is near the top of the room. In summer, top exits and cross currents should be provided to remove excessive heat. Hot stables are almost always poorly ventilated, and the hot stable is a cause of disease on account of the extreme change of temperature that a horse is liable to when taken out, and extreme changes of temperature are to be avoided as certain causes of disease.
The causes of many of the diseases of these organs may be given under a common head, because even a simple cold, if neglected or badly treated, may run into the most complicated lung disease and terminate fatally. In the spring and fall, when the animals are changing their coats, there is a marked predisposition to contract disease, and consequently at those periods care should be taken to prevent other exciting causes.
The mucous membrane lining the nasal chambers, and, in fact, the entire respiratory tract, is much more delicate and more frequently diseased that the mucous membrane of any other part of the body. The sinuses of the head are compartments which communicate with the nasal chambers and are lined with a continuation of the same membrane that lines the nasal chambers; their presence increases the volume and modifies the form of the head without increasing its weight.
The horse, in a normal condition, breathes exclusively through the nostrils. The organs of respiration are quite liable to become diseased, and, as many of the causes which lead to these attacks can be avoided, it is both important and profitable to know and study the causes.
Just within the nasal openings the skin becomes gradually but perceptibly finer, until it is succeeded by the mucous membrane. Near the junction of the skin and membrane is a small hole, presenting the appearance of having been made with a punch; this is the opening of the lachrymal duct, a canal that conveys the tears from the eyes. Within and above the nasal openings are the cavities, or fissures, called the false nostrils. The nasal chambers are completely separated, the right from the left, by a cartilaginous partition, the nasal septum. Each nasal chamber is divided into three continuous compartments by two thin, scroll-like turbinated bones.
The pleura is a thin membrane that envelops the lung and lines the walls of the thoracic cavity. The diaphragm is a muscular structure, completely separating the contents of the thoracic cavity from those of the abdominal cavity. It is essentially a muscle of inspiration, and the principal one. Other muscles aid in the mechanism of respiration, but the diseases or injuries of them have nothing to do with the diseases under consideration.
The organs pertaining to the respiratory function may be enumerated in natural order as follows: The nasal openings, or nostrils; the nasal chambers, through which the air passes in the head; the sinuses in the head, communicating with the nasal chambers; the pharynx, common to the functions of breathing and swallowing; the larynx, at the top of the windpipe; the trachea, or windpipe; the bronchi (into which the windpipe divides), two tubes leading from the windpipe to the right and left lungs, respectively; the bronchial tubes, which penetrate and convey air to all parts of the lungs; the lungs.
Aneurisms impede the circulation of the blood, and may give rise to intermittent lameness. The aneurism may rupture, since it constitutes a weak place in the wall of the blood vessel, and the horse die of the resulting hemorrhage. Particles of blood clots in the aneurisms may break off and plug a blood vessel at the point where they lodge, thereby causing the death of the part from which the blood is shut off and occasioning a type of colic which often terminates fatally. The larvae of Cylicostomum form cysts in the walls of the large intestine, and when these open they give rise to small sores; when they are numerous they cause a thickening and hardening which impair the proper functioning of the intestine. Abscesses sometimes perforate, causing death. The adult worm attacks the intestinal wall, causing bleeding which results in anemia. The numerous small sores thus caused allow bacteria to get into the circulation, sometimes resulting in localized abscesses or in septic arthritis or joint disease.
The disease due to these worms is quite common. The worms enter the body as immature forms in the spring, when the animal is turned out on pasture. The first symptoms show in November or December, the disease being in a latent stage during the development of the worms. The first symptoms are diarrhea, loss of appetite, and emaciation. The animal becomes anemic. Secondary symptoms are edema and such complications as joint infection, colic due to embolism, and accidents from falls, hemorrhage from ruptured aneurisms, or perforation at the site of abscess. The animal may die, recover, or become a chronic sufferer, the internal injuries failing to make a satisfactory recovery even with the removal of the worms in chronic cases.
Treatment calls for the expulsion of the adult worms from the intestine, the development of the body resistance to repair the damage wrought by the developing worms, and the combating of complications. For the expulsion of the worms the use of carbon bisulphid in gelatin capsules, 2 to 5 grams, according to the size of the patient, for five days, followed by magnesium sulphate the sixth day, has been recommended. Owing to the difficulty and danger in the administration of carbon bisulphid in capsule, it is advisable to call in a veterinarian. Tonic treatment consists in the subcutaneous administration of artificial serum and caffein. The various complications of bacterial infection, colic, heart depression, etc., call for the attention of a veterinarian. Preventive measures consist in avoiding reinfection with worms so far as possible by using dry upland pasture in preference to low, wet land, and by rotating pastures or rotation of the stock on a given pasture. Horses may be alternated with cattle, sheep, or hogs to advantage, so far as parasites are concerned. Another feature, always of importance, is the provision of a pure, potable drinking water.
Bots (Gastrophilus spp.). Bots (Pl. VI) are quite common in the stomach and upper part of the small intestine of the horse anywhere in the United States, one kind being occasionally found in the rectum. They attach to that portion of the mucous lining of the stomach nearest the esophagus or sometimes around the pyloric opening to the intestine or even in the upper intestine, and undoubtedly interfere with the proper functioning of the stomach and the health of the animal to a certain extent. The symptoms are rather vague as a rule, but the general result is a condition of unthriftiness.
A treatment which has been found effective consists in feeding lightly on the day preceding treatment, withholding food in the evening and giving an ounce of Barbados aloes or a pint of linseed oil. The next day give 3 drams of carbon bisulphid in a gelatin capsule at 6 o'clock, repeat the dose at 7 o'clock, and again at 8 o'clock, making a total of 9 drams altogether for an adult horse; half that amount will be sufficient for a yearling colt. As previously noted, there is some little difficulty and danger of accident in the administration of treatments of this character and it is advisable to call in a veterinarian.
Unless destroyed by treatment, the bots in the stomach of the horse pass out in the manure in the spring and burrow down into the soil an inch or two. Here they undergo a certain amount of development and finally emerge as adult flies. These bot flies mate and during the summer the eggs are deposited by the female on the forelegs and shoulders or around the chin, mouth and nostrils of the horse, the location and appearance of the eggs varying somewhat with different species of bot flies. These eggs or the young maggots escaping from them are ingested by the horse in licking the portions irritated by the movement of the escaping maggots, and when swallowed develop to form bots in the stomach. Careful currying, especially around the forequarters, is an aid in keeping down bot infestation, but this is not commonly feasible with horses on pasture, the ones most liable to become infested.
The larvae of Strongylus equinus are found principally in the liver, lungs, and pancreas.
The larvae of Strongylus edentatus may be met with almost anywhere, especially under the serous membranes, the pleura and peritoneum.
The embryos and larvae of species of Cylicostomum are found in the mucosa of the large intestine.
The larva of Strongylus vulgaris enters the blood vessels of the intestinal wall and finally attaches in the great mesenteric artery, where it causes aneurisms; here it transforms to an adult without sexual organs, which passes to the walls of the cecum and encysts, giving rise to small cysts or abscesses; these cysts finally discharge to the interior of the cecum, setting the worms, now mature, at liberty in the lumen of the intestines.
Apparently it is the young forms of these stomach worms which develop at times on the skin, causing a cutaneous habronemiasis known as summer sores. This is discussed under diseases of the skin.
Strongyles (Strongylus spp. and Cylicostomum spp.). These worms (Pl. V, figs. 2 and 3) live in the large intestines of the horse as adult worms and are often present in enormous numbers. Many of them are very small, and the largest are less than two inches long. The adult worms do considerable damage, but the immature or larval worms do even more.
Stomach worms of the horse (Habronema spp.). These worms (Pl. V, fig. 4) occur in nodules in the mucous lining of the horse's stomach and are credited with doing more or less damage. Their presence is not likely to be diagnosed in the present state of our knowledge, but in case their presence is determined or suspected in connection with the summer sores noted later, tartar emetic is recommended. At least one of these worms has an intermediate stage in the ordinary housefly, the fly becoming infested while it is a larva developing in horse manure. Obviously, therefore, any measures looking toward the eradication of the fly or the proper disposal of manure will aid in the control and eradication of this worm. The United States Bureau of Entomology has shown that fly maggots travel downward through a manure pile as it comes time for the maggot to enter the ground and pupate, and an excellent maggot trap, consisting of an exposed manure platform raised on posts which are set in a concrete basin extending under the platform and filled with three or four inches of water, has been devised. As maggots work down they come to the platform and escape through the spaces between the boards, left open for the purpose, to the water in the concrete basin, where they are drowned. In this way the exposed manure pile serves to attract flies with a deceptive proffer of a breeding place.
Pinworm (Oxyuris equi). This is a rather large worm (Pl. V, fig. 1), somewhat smaller than the foregoing and readily distinguishable from it by the presence of a long, slender tail. It also occurs generally throughout the United States, and except when present in large numbers probably does very little damage. It inhabits the large intestine and hence is difficult to reach with medicines administered by the mouth. The use of a half ounce of gentian on the feed night and morning for a week has been recommended, but the use of rectal enemas will give more prompt and perhaps more certain results. These enemas may be made up with one or two tablespoonfuls of salt to the pint, or infusions of quassia chips, a half pound to the gallon of water, and injected into the rectum once or twice a day.
Treatment for the removal of this worm consists in the use of anthelmintics such as tartar emetic, turpentine, and carbon bisulphid, but as these remedies are essentially poisons intended to kill the worm, and as their use by persons unused to determining conditions unfavorable for their use is dangerous and likely to result in the death of the animal or in permanent injury to the kidneys or other organs, it is advisable to call in a veterinarian in such cases.
Flukes occur in horses elsewhere, but have apparently never been reported in the United States.
Roundworms, or nematodes, constitute the most important group of parasitic worms in the horse. The more important of these are as follows:
Roundworm (Ascaris equorum). This is the common large, yellowish roundworm (Pl. V, fig. 5), about the size of a lead pencil or larger, which may be found in horses almost anywhere in the United States. It occurs in the intestine and probably occasions little damage as a rule, except when present in large numbers, in which case it will probably be found in the droppings. The symptoms occasioned by it are rather obscure and are such as might arise from a number of other causes, namely, colicky pains, depraved appetite, diarrhea or constipation, and general unthriftiness. In a general way, the presence of parasites may be suspected when an animal shows no fever but is unthrifty, debilitated, and shows disordered bowel movements in cases where there is no evident explanation in the way of feed, care, and surroundings.
Horses are subject to infestation by a number of species of worms, these worms being especially numerous at certain points in the alimentary canal.
The tapeworms of the horse are relatively unimportant and not very common. There are three species, the smallest about two inches long and the largest about eight inches long. These two occur in the small intestine; a form intermediate in size may also be found in the cecum and colon. These are flat, segmented worms with the head at the smaller end.
Diseases of the pancreas and spleen are so rare, or their symptoms so little understood, that it is impossible to write anything concerning either of these organs and their simple diseases that will convey to the reader information of practical value.
These are rarely found in the horse, but may occupy the hepatic ducts, giving rise to jaundice and to colicky pains. There are no absolutely diagnostic symptoms, but should one find a horse that suffers from repeated attacks of colic, accompanied with symptoms of violent pain, and that during or following these attacks the animal is jaundiced, it is possible that gallstones are present. There is little or nothing to be done except to give medicines to overcome pain, trusting that these concretions may pass on to the bowels, where, from their small size, they will not occasion any inconvenience.
Treatment. But little can be done in the way of treatment. Opium in powder, in doses of 2 drams every two or three hours, may be given, with the idea of preventing as much as possible all movements of internal organs. If there is reason to suspect internal bleeding, we should give large and frequent doses of white-oak bark tea, dram doses of tannic or gallic acid, or the same quantity of sugar of lead, every half hour or hour. Fluid extract of ergot or tincture of the chlorid of iron, in ounce doses, may be selected. Cold water dashed upon the right side or injected into the rectum is highly spoken of as a means of checking the hemorrhage.
The immediate causes of rupture appear to be excessive muscular exertion, as leaping a fence, a fall, a blow from a collision, a kick from a horse, or sudden distention of the abdomen with gas.
The symptoms of rupture of the liver will depend upon the extent of the laceration. If slight, there will be simply the symptoms of abdominal pain, looking back to the sides, lying down, etc.; if extensive, the horse is dull and dejected, has no appetite, breathing becomes short and catching, he sighs or sobs, visible mucous membranes are pale, extremities cold, pulse fast, small, and weak or running down. Countenance now shows much distress, he sweats profusely, totters in his gait, props his legs wide apart, reels, staggers, and falls. He may get up again, but soon falls dead. The rapid running-down pulse, paleness of the eyes, nose, and mouth, sighing, stertorous breathing, tottering gait, etc., are symptoms by which we know that the animal is dying from internal hemorrhage.
This is known to occur at times in the horse, most frequently in old, fat horses and those that get but little exercise. Horses that have suffered from chronic liver disease for years eventually present symptoms of colic and die quite suddenly. Upon post-mortem examination we discover that the liver has ruptured. The cicatrices, or scars, that are often found upon the liver indicate that this organ may suffer small rupture and yet the horse may recover from it. This can not be the result, however, if the rent or tear is extensive, since in such cases death must quickly follow from hemorrhage, or, later, from peritonitis. Enlarged liver is particularly liable to rupture.
Treatment. When jaundice exists we must endeavor to rid the system of the excess of bile, and this is best accomplished by giving purgatives that act upon the liver. Calomel, 2 drams, with aloes, 7 drams, should be given. Glauber's salt in handful doses once or twice a day for a week is also effective. May apple, rhubarb, castor oil, and other cathartics that act upon the first or small bowels may be selected. We must be careful to see that the bowels are kept open by avoiding hard, dry, bulky feeds.
This is a condition caused by the retention and absorption of bile into the blood. It was formerly considered to be a disease of itself, but is now regarded as a symptom of disorder of the liver. "The yellows" is observed by looking at the eyes, nose, and mouth, when it will be seen that these parts are yellowish instead of the pale-pink color of health. In white or light-colored horses the skin even may show this yellow tint. The urine is saffron colored, the dung is of a dirty-gray color, and constipation is usually present. Jaundice may be present as a symptom of almost any inflammatory disease. We know that when an animal has fever the secretions are checked, the bile may be retained and absorbed throughout the system, and yellowness of the mucous membranes follows. Jaundice may also exist during the presence of simple constipation, hepatitis, biliary calculi, abscesses, hardening of the liver, etc.
Treatment. This should consist, at first, of the administration of 1 ounce of Barbados aloes or other physic. General blood-letting, if had recourse to early, must prove of much benefit in acute inflammation of the liver. The vein in the neck (jugular) must be opened, and from 4 to 6 quarts of blood may be drawn. Saline medicines, as Glauber's salt or the artificial Carlsbad salt, are indicated. These may be given with the feed in tablespoonful doses. The horse is to be fed sparingly on soft feed, bran mashes chiefly. If treatment proves successful and recovery takes place, see to it that the horse afterwards gets regular exercise and that his feed is not of a too highly nutritious character and not excessive.
Causes. Among the causes that lead to this disease we must mention first the stimulating effect of overfeeding, particularly during hot weather. Horses that are well fed and receive but little exercise are the best subjects for diseases of this organ. We must add to these causes the more mechanical ones, as injuries on the right side over the liver, worms in the liver, gallstones in the biliary ducts, foreign bodies as needles or nails that have been swallowed and in their wanderings have entered the liver and, lastly, in some instances, the extension of inflammation from neighboring parts, thus involving this organ. Acute hepatitis may terminate in chronic inflammation, abscesses, rupture of the liver, or may disappear, leaving behind no trace of disease whatever.
This disease may be general or local, and may assume an acute or chronic form.
Symptoms. The symptoms of acute hepatitis are: Dullness; the horse is suffering from some internal pain, but not of a severe type; constipated and clay-colored dung balls; scanty and high-colored urine; and general febrile symptoms. If lying down, he is mostly found on the left side; looks occasionally toward the right side, which, upon close inspection, may be found to be slightly enlarged over the posterior ribs, where pain upon pressure is also evinced. Obscure lameness in front, of the right leg mostly, may be a symptom of hepatitis. The horse, toward the last, reels or staggers in his gait and falls backward in a fainting fit, during one of which he finally succumbs. Death is sometimes due to rupture of the enveloping coat of the liver or of some of its blood vessels.
In the United States the liver of the horse is but rarely the seat of disease, and when we consider how frequently the liver of man is affected this can not but appear strange. The absence of the gall bladder may account to a certain extent for his freedom from liver diseases, as overdistention of this and the presence in it of calculi (stones) in man is a frequent source of trouble. In domestic animals, as in man, hot climates tend to produce diseases of the liver, just as in cold climates lung diseases prevail. Not only are diseases of the liver rare in horses in temperate climates, but they are also very obscure, and in many cases pass totally unobserved until after death. There are some symptoms, however, which, when present, should make us examine the liver as carefully as possible. These are jaundice (yellowness of the mucous membranes of the mouth, nose, and eyes) and the condition of the dung, it being light in color and pasty in appearance.
Treatment is, as a rule, unsatisfactory. Saline cathartics, as Epsom or Glauber's salt, and diuretics, ounce doses of saltpeter, may be given. If a veterinarian is at hand he will withdraw the accumulation of water by tapping and then endeavor to prevent its recurrence (though this is almost sure to follow) by giving three times a day saltpeter 1 ounce and iodid of potash 1 dram, and by the application of mustard or blisters over the abdominal walls. Tonics, mineral and vegetable, are also indicated. Probably the best tonic is one consisting of powdered sulphate of iron, gentian, and ginger in equal parts; a heaping tablespoonful of the mixture is given as a drench or mixed with the feed, twice a day. Good nutritious feeds and gentle exercise complete the treatment.
