DISEASES OF THE DIGESTIVE ORGANS.
DESCRIPTION OF PLATES.
Plate I. Position of the first stomach (rumen or paunch) on the left side. The area inclosed by heavy dotted lines represents the rumen; the elongated, shaded organ is the spleen resting upon it. The skin and muscles have been removed from the ribs to show the position of the lungs and their relation to the paunch.
Plate II. Stomach of ruminants.
Fig. 1. Stomach of a full-grown sheep, 1/5 natural size (after Thanhoffer, from R. Meade Smith's Physiology of Domestic Animals): a, rumen, or first stomach; b, reticulum, or second stomach; c, omasum, or third stomach; d, abomasum, or fourth stomach; e, esophagus, or gullet, opening into the first and second stomachs; f, opening of fourth stomach into small intestine; g, opening of second stomach into third; h, opening of third stomach into fourth.
The lines indicate the course of the food in the stomachs. The incompletely masticated food passes down the esophagus, or gullet, into the first and second stomachs, in which a churning motion is kept up, carrying the food from side to side and from stomach to stomach. From the first stomach regurgitation takes place; that is, the food is returned through the gullet to the mouth to be more thoroughly chewed, and this constitutes what is known as "chewing the cud." From the second stomach the food passes into the third, and from the third into the fourth, or true, stomach, and from there into the intestines.
Fig. 2. Stomach of ox (after Colin, from R. Meade Smith's Physiology of Domestic Animals): a, rumen; b, reticulum; c, omasum; d, abomasum; e, esophagus; f, opening of fourth stomach into small intestine.
Fürstenberg calculated that in an ox of 1,400 pounds weight the capacity of the stomach is as follows:
| Per cent. | |
|---|---|
| Rumen, 149.25 quarts, liquid measure | 62.4 |
| Reticulum, 23.77 quarts | 10.0 |
| Omasum, 36.98 quarts | 15.0 |
| Abomasum, 29.05 quarts | 12.6 |
According to Colon—
| Quarts. | |
|---|---|
| The capacity of a beef's stomach is | 266.81 |
| Small intestine | 69.74 |
| Cecum | 9.51 |
| Colon and rectum | 25.58 |
Plate III. Instruments used in treating diseases of digestive organs.
Fig. 1. Clinical thermometer, 4/5 natural size. This is used to determine the temperature of the animal body. The thermometer is passed into the rectum after having been moistened with a little saliva from the mouth, or after having had a little oil or lard rubbed upon it to facilitate its passage. There it is allowed to remain two or three minutes, then withdrawn, and the temperature read as in any ordinary thermometer. The clinical thermometer is made self-registering; that is, the mercury in the stem remains at the height to which it was forced by the heat of the body until it is shaken back into the bulb by taking hold of the upper portion of the instrument and giving it a short, sharp swing. The normal temperature of cattle varies from 100° to 103° F. In young animals it is somewhat higher than in old. The thermometer is a very useful instrument and frequently is the means by which disease is detected before the appearance of any external sign.
Plate III. Instruments used in treating diseases of digestive organs—Contd.
Fig. 2. Simple probang, used to dislodge foreign bodies, like apples, potatoes, eggs, etc., which have become fastened or stuck in the esophagus or gullet.
Fig. 3. Grasping or forceps probang. This instrument, also intended to remove obstructions from the gullet, has a spring forceps at one end in the place of the cup-like arrangement at the end of the simple probang. The forceps are closed while the probang is being introduced; their blades are regulated by a screw in the handle of the instrument. This probang is used to grasp and withdraw an article which may have lodged in the gullet and can not be forced into the stomach by use of the simple probang.
Fig. 4. Wooden gag, used when the probang is to be passed. The gag is a piece of wood which fits in the animal's mouth; a cord passes over the head to hold it in place. The central opening in the wood is intended for the passage of the probang.
Figs. 5a and 5b. Trocar and cannula; 5a shows the trocar covered by the cannula; 5b, the cannula from which the trocar has been withdrawn. This instrument is used when the rumen or first stomach becomes distended with gas. The trocar covered by the cannula is forced into the rumen, the trocar withdrawn, and the cannula allowed to remain until the gas has escaped.
Fig. 6. Section at right angles through the abdominal wall, showing a hernia or rupture. (Taken from D'Arboval. Dictionnaire de Médecine, de Chirurgie de Hygiene): a a, The abdominal muscles cut across; v, opening in the abdominal wall permitting the intestines i i to pass through and outward between the abdominal wall and the skin; p p, peritoneum, or membrane lining the abdominal cavity, carried through the opening o by the loop of intestine and forming the sac S, the outer walls of which are marked b f b.
Plate IV. Microscopic anatomy of the liver. The liver is composed of innumerable small lobules, from 1/20 to 1/10 inch in diameter. The lobules are held together by a small amount of fibrous tissue, in which the bile ducts and larger blood vessels are lodged.
Fig. 1 Illustrates the structure of a lobule; v v, interlobular veins or the veins between the lobules. These are branches of the portal vein, which carries blood from the stomach and intestines to the liver; c c, capillaries, or very fine blood vessels, extending as a very fine network between the groups of liver cells from the interlobular vein to the center of the lobule and emptying there into the intralobular vein to the center of the lobule; v c, intralobular vein, or the vein within the lobule. This vessel passes out of the lobule and there becomes the sublobular vein; v s, sublobular vein. This joins other similar veins and helps to form the hepatic vein, through which the blood leaves the liver; d d, the position of the liver cells between the meshes of the capillaries; A A, branches of the hepatic artery to the interlobular connective tissue and the walls of the large veins and large bile ducts. These branches are seen at r r and form the vena vascularis; v v, vena vascularis; i i, branches of the hepatic artery entering the substance of the lobule and connecting with capillaries from the interlobular vein. The use of the hepatic artery is to nourish the liver, while the other vessels carry blood to be modified by the liver cells in certain important directions; g, branches of the bile ducts, carrying bile from the various lobules into the gall bladder and into the intestines; x x, intralobular bile capillaries between the liver cells. These form a network of very minute tubes surrounding each ultimate cell, which receives the bile as it is formed by the liver cells and carried outward as described.
Fig. 2. Isolated liver cells: c, blood capillary; a, fine bile capillary channel.
Plate V. Ergot in hay: 1, bluegrass; 2, timothy; 3, wild rye; 4, redtop. Ergot is a fungus which may affect any member of the grass family. The spore of the fungus, by some means brought in contact with the undeveloped seed of the grass, grows, obliterates the seed, and practically takes its place. When hay affected with ergot is fed to animals it is productive of a characteristic and serious affection or poisoning known as ergotism.
Plate VI. Ergotism, or the effects of ergot. The lower part of the limb of a cow, showing the loss of skin and flesh in a narrow ring around the pastern bone and the exposure of the bone itself.
POISONS AND POISONING.
By V. T. Atkinson, V. S.
[Revised by C. Dwight Marsh, Ph. D.]
DEFINITION OF A POISON.
To define clearly the meaning of the word "poison" is somewhat difficult. Even in law the word has never been defined, and when a definition is attempted we are apt to include either too much or too little. The following definition given by Husemann is perhaps the best: "Poisons are those substances, inorganic or organic, existing in the organism or introduced from the outside, produced artificially or formed as natural products, which, through their chemical nature, under definite conditions, so affect some organ of a living organism that the health or well-being of the organism is temporarily or chronically injured." The common conception of a poison is any substance which, in small quantity, will destroy life, except such as act by purely mechanical means, as, for example, powdered glass.
Some substances that are not usually looked upon as poisons may destroy life if given in large doses, such as common salt. Other substances which are perfectly harmless when taken into the body in the usual way are poisons if injected into the circulation, such as distilled water, milk, or glycerin. Living organisms are not "chemical substances," and are not considered in this connection.
SOURCES OF POISONING.
Poisoning may come from many causes, among the chief of which are the following:
(1) Errors in medication.—By using the wrong substance or too large dose an animal may be poisoned.
(2) The exposure of poisons used for horticultural, technical, or other legitimate purposes.—Poisons used for spraying plants, disinfecting, poisoning vermin, dipping cattle or sheep, painting, smelting, dyeing, or other purposes may be so handled as to come within the reach of animals.
(3) Damaged food.—Food that has undergone putrefaction or certain kinds of fermentation or heating, may have become poisonous, producing forage poisoning, meat poisoning, cheese poisoning, etc.
(4) Poisonous plants in the pasture or forage.
(5) The bite or sting of a poisonous insect or the bite of an animal.
(6) Malicious poisoning.
THE ACTION OF POISONS.
The action of poisons may be either local, and exerted directly on the tissues with which they come in contact, or remote, acting through the circulation or the nervous system; or both local and remote action may be exerted by the same drug. Poisons which act locally generally either destroy by corrosion the tissues with which they come in contact or by inhalation set up acute inflammation. When any corrosive agent is taken into the stomach in poisonous quantities, a group of symptoms is developed which is common to all. The tissues with which the agent comes in contact are destroyed, sloughing and acute inflammation of the surrounding structures take place; intense pain in the abdomen and death ensue. In a like manner, but with less rapidity, the same result is reached if the agent used be not of a sufficiently corrosive nature to destroy the tissues, but sufficiently irritating to set up acute inflammation of the mucous membrane of the digestive tract. If the poison exerts a remote influence alone, the action is quite different, little or no local effect being produced upon the digestive organs.
To produce an effect on some part of the body distant from the channel of entrance, a poison must have been absorbed and carried in the blood to the central nervous system or other region involved. The poisonous effect of any substance is modified by the quantity used; by its chemical combinations; by the part of the animal structure with which it comes in contact; by the physical condition of the subject; and also by the rapidity with which the poison is excreted. As an illustration, opium may be given with safety in much larger doses to an animal suffering from acute pain than to one free from pain, and to an adult animal with greater safety than to a young one. The rapidity with which the poison is absorbed, owing to the part of the body with which it is brought in contact, is also an important factor. So marked is this quality that some agents which have the power of destroying life with almost absolute certainty when introduced beneath the skin, may be taken into the stomach without causing inconvenience, as curara, the arrow poisons, or the venomous secretion of snakes. Other agents in chemical combination may tend to intensify, lessen, or wholly neutralize the poisonous effect. For example, arsenic in itself has well-marked poisonous properties, but when brought in contact with dialyzed iron it forms an insoluble compound and becomes innocuous. Idiosyncrasies are not so noticeable in cattle practice as in practice among human beings, but the uncertainty with which some drugs exert their influence would lead us to believe that well-marked differences in susceptibility exist. Even in some cases a tolerance for poison is engendered, so that in a herd of animals equally exposed injurious or fatal effects do not appear with uniformity. For example, among cattle that are compelled to drink water holding in solution a salt of lead the effects of the poisoning will be found varying all the way from fatality to imperceptibility.
GENERAL SYMPTOMS OF POISONING.
It is not always easy to differentiate between poisoning and some disease. Indeed, examination during the life of the animal is sometimes wholly inadequate to the formation of an opinion as to whether the case is one of poisoning or, if it is, as to what the poison may be. A chemical and physical examination after the death of the animal may be necessary to clear up the doubt. On the other hand, the symptoms may be of such a nature as to point unmistakably to poisoning with a certain agent. In general, the following classes of symptoms may be regarded as indicative of poisoning: Sudden onset of the disease without visible cause, a number of animals being similarly affected at once, with severe gastrointestinal disorder or derangement of the nervous system, or both; sudden alteration of heart action in relation to frequency, force, or rhythm; local irritation, dyspnea, or change in the urine or urination.
After death, lesions of the greatest variety may be found, and it is necessary for one to be skilled in anatomy and pathology in order to determine their significance. Oftentimes the stomach and intestines are red, have thick walls, and contain blood. This signifies a severe irritant, such as arsenic or corrosive sublimate. Other alterations sometimes found are inflammation of the kidneys or bladder, points of hemorrhage in various organs, changes in the blood, congestion of the lungs, and certain microscopic changes.
GENERAL TREATMENT.
The treatment of animals suffering from poison must vary according to the nature of the toxic agent. There are a few general plans of action, however, which should be followed so far as possible. In man and in some of the smaller animals it is possible to eliminate unabsorbed poison by the use of the stomach pump or by causing vomiting. These proceedings are impracticable in cattle. It is well, therefore, in many cases to endeavor to expel the unabsorbed poison by emptying the digestive tract, so far as may be, with a nonirritating purge. Castor oil in doses of 1 pint to 2 quarts is adapted to this purpose. If the poison is known to be nonirritant—as a narcotic plant—from 10 to 20 drops of croton oil may be given with a quart of castor oil. When poisons are somewhat prolonged in their effect, Epsom salt in doses of 1 pound can be given advantageously. To protect the mucous membrane from the action of strong irritants, one may give flaxseed tea, barley water, the whites of eggs, milk, butter, olive oil, or fresh lard. Chemical antidotes may sometimes be used for special poisons, as advised below. In general, if an acid has been taken it may be neutralized with an alkali, such as chalk, magnesia, bicarbonate of soda (baking soda), ammonia (diluted), or soap. If the poison is an alkali, such as caustic soda or potash (lye), or ammonia, an acid, such as diluted (1 per cent) sulphuric acid or vinegar, may be administered. Special treatments and antidotes are considered below.
A poisonous agent may be so gradually introduced into the system as to slowly develop the power of resistance against its own action. In other cases where the poison is introduced slowly the poisonous action becomes accumulative, and, although there is no increase in the quantity taken, violent symptoms are suddenly developed, as if the whole amount, the consumption of which may have extended over a considerable period, had been given in one dose. Other agents, poisonous in their nature, tend to deteriorate some of the important organs, and, interfering with their natural functions, are productive of conditions of ill health which, although not necessarily fatal, are important. Such might properly be called chronic poisons. Poisons of themselves dangerous when administered in large doses are used medicinally for curative purposes, and a very large percentage of the pharmaceutical preparations used in the practice of medicine if given in excessive quantities may produce serious results. In the administration of medicines, therefore, care should be exercised not only that the animal is not poisoned by the administration of an excessive dose but that injury is not done by continued treatment with medicines the administration of which is not called for.
MINERAL POISONS.
ARSENIC POISONING.
Of the common irritant and corrosive poisons, arsenic, especially one of its compounds (Paris green), is likely to be the most dangerous to our class of patients. The common practice of using Paris green and other compounds of arsenic as insecticides for the destruction of potato beetle and other insect enemies of the farmer and fruit grower has had the effect of introducing it into almost all farming establishments. White arsenic is also a principal ingredient in some popular dipping preparations, and poisoning from this source occasionally takes place when, after dipping, animals are allowed to run in a yard in which there is loose fodder. The drippings from the animals falling on the fodder render it poisonous and dangerous to animal life if eaten. Familiarity with its use has in many instances tended to breed contempt for its potency as a poison. Rat poisons often contain arsenic. The excessive use of arsenic as a tonic, or of "condition powders" containing arsenic, has been the means of poisoning many animals. This is the common poison used by malicious persons with criminal intent. The poison may also be absorbed through wounds or through the skin if used as a dip or bath.
If a large dose is given, at once acute poisoning is produced; if repeated small doses are given, chronic poisoning may result. The poisonous dose for an ox is from 3 drams to 1 ounce.
Symptoms.—The symptoms of acute poisoning first appear as those of colic; the animal is restless, stamping with the feet, lying down and getting up. There is tenderness on pressure over the abdomen. The acute symptoms increase; in a few hours violent diarrhea is developed; in many cases blood and shreds of detached mucous membrane are mixed with the evacuations. There is irregular and feeble pulse and respiration, and death is likely to supervene between the eighteenth hour and the third day. If the latter period is passed, there is a reasonable hope of recovery.
In chronic poisoning the symptoms are similar to those of chronic gastrointestinal catarrh, with indigestion, diarrhea, and general weakness and loss of condition.
Treatment.—The antidote for arsenic is a solution of hydrated oxid of iron in water. It should be prepared fresh by mixing a solution of sulphate of iron, made by dissolving 4 ounces of sulphate of iron in one-half pint water, with a suspension of 1 ounce of magnesia in one-half pint water. This quantity is sufficient for one dose for a cow and may be repeated in an hour, if much arsenic was taken. A solution of calcined magnesia or powdered iron or iron filings or iron scale from a blacksmith's forge may be given in the absence of other remedies. Powdered sulphur is of some value as an antidote. One must also administer protectives, such as linseed tea, barley water, whites of eggs, etc.
LEAD POISONING.
Lead poisoning of cattle sometimes comes from their having licked freshly painted surfaces and thus swallowed compounds containing white lead. In several instances cattle have been poisoned by silage from a silo painted inside with lead paint shortly before filling. Sometimes cattle eat dried paint scrapings with apparent relish and are poisoned. Cattle grazing on rifle ranges have been poisoned by lead from the bullets. Sugar of lead has been administered by mistake for Glauber's salt. Lead poisoning may be acute or chronic. The fatal dose of sugar of lead is from 1 to 4 ounces. Water drawn from lead pipes or held in a lead-lined tank may cause poisoning.
Symptoms.—The symptoms are generally dullness, lying down with the head turned toward the flank, colic, rumbling in the abdomen, loss of control of the limbs when walking, twitching, champing of the jaws, moving in a circle, convulsions, delirium, violent bellowing, followed by stupor and death. The symptoms generally extend over considerable time but may end in death after 24 hours.
Chronic lead poisoning occasionally occurs in districts where lead mining is the principal industry. The waste products of the mine thrown into streams contaminate the water supply, so that the mineral is taken into the system gradually, and a very small per cent of any of the salts taken into the system in this way is pernicious. Water which contains any salt of lead to the extent of more than one-tenth of a grain to the gallon is unfit to drink. Such water when used continually is likely to produce colic from the resulting intestinal irritation, and in aggravated cases paralysis more or less severe is likely to be developed. A blue line on the margin of the gums, the last symptom, is regarded as diagnostic and its presence as conclusive evidence of the nature of the disorder.
Treatment.—The treatment should first be directed toward removing the cause. A large dose of purgative medicine should be given, and the brain symptoms be relieved by giving bromid of potassium in half-ounce doses every 4 or 5 hours and by the application of cold water to the head. Dilute sulphuric acid in half-ounce doses should be given with the purgative medicine. In this case sulphate of magnesia (Epsom salt) is the best purgative, and it may be given in doses of from 1 to 2 pounds dissolved in warm water. After the acute symptoms have abated, iodid of potassium may be given, in doses of 2 drams each, three times a day for a week.
No treatment is likely to be of avail until the cause is removed.
COPPER POISONING.
The soluble salts of copper, though used as a tonic in the medicinal treatment of cattle, are poisonous when taken in large quantities. Like lead and arsenic, they have an irritant effect upon the mucous membrane with which they come in contact in a concentrated form. Cattle are not very likely to be poisoned from this cause unless through carelessness. Sulphate of copper, commonly called blue vitriol, is occasionally used for disinfecting and cleansing stables, where it might inadvertently be mixed with the feed. It is also used largely for making the Bordeaux mixture used in spraying fruit trees. The general symptoms produced are those of intestinal irritation, short breathing, stamping, and tender abdomen.
Treatment.—Give powdered iron, or iron reduced by hydrogen, or calcined magnesia. Sulphur may be used. This should be followed by a liberal supply of demulcents, linseed infusion, boiled starch, whites of eggs, etc.
ZINC POISONING.
Several of the soluble salts of zinc are irritant poisons. The chlorid and sulphate are those in most common use. In animals which have power to vomit they are emetic in their action. In others, when retained in the stomach, they set up more or less irritation of the mucous membrane and abdominal pain, producing symptoms already described in the action of other poisons which produce the same result.
Treatment.—The treatment should be the same as for copper poisoning.
PHOSPHORUS POISONING.
Only one of the forms of phosphorus in common use—the ordinary yellow—is poisonous. Phosphorus in this form is used for the destruction of rats and mice and other vermin, and has been largely used in the manufacture of matches.
Symptoms.—The symptoms are loss of appetite, colic, diarrhea, irritation of the mouth and throat, and paralysis of the throat. There is also weakness, difficult breathing, and rapid pulse. The course of the poisoning is usually rapid, terminating in either recovery or death within three days. The toxic dose for cattle is from 5 to 30 grains. If taken in large quantities the excreta are occasionally noticed to be luminous when examined in the dark.
Treatment.—Turpentine is given in an emulsion with flaxseed tea in a single dose of from 2 to 8 ounces. Permanganate of potassium may be given in a one-fourth of 1 per cent solution. Stimulants, such as alcohol and ether, should be administered. Oils and milk must not be given.
MERCURY POISONING.
Mercury poisoning is not rare in cattle from the fact that these animals have a special susceptibility to the action of this substance. Antiseptic washes or injections containing the bichlorid of mercury (corrosive sublimate) must be used on cattle with great care. Mercurial disinfecting solutions or salves must be used cautiously. Calomel can not be given freely to cattle.
Symptoms.—The symptoms are salivation, sore mouth, indigestion, diarrhea, skin eruption, paralysis of local groups of muscles, and nephritis.
Treatment.—The treatment consists in administering sulphur in large doses (2 to 4 ounces) or iron powder. Both make insoluble compounds with mercury. Follow with the whites of eggs mixed with water and with linseed tea. If the case does not terminate promptly, give iodid of potash in 1-dram doses twice daily.
POISONING BY ACIDS.
Mineral acids.—The mineral acids—nitric, sulphuric, hydrochloric, etc.— when used in a concentrated form destroy the animal tissues with which they come in contact, and in this respect differ from most of the poisons previously described. When taken into the stomach the mucous membrane of the mouth, pharynx, esophagus, and stomach is apt to be more or less completely destroyed. If taken in large quantities death is likely to result so speedily that nothing can be done to relieve the patient, and even if time is allowed and the action of the acid can be arrested it can not be done until considerable and, perhaps, irreparable damage has been done. The mucous membrane with which the acid has come in contact in the esophagus may be destroyed by its corrosive action and carried away, leaving the muscular tissues exposed. The raw surface heals irregularly, the cicatrice contracting causes stricture, and an animal so injured is likely to die of starvation. In the stomach even greater damage is likely to be done. The peristaltic action of the esophagus carries the irritant along quickly, but here it remains quiet in contact with one surface, destroying it. It is likely to perforate the organ and, coming in contact with the abdominal lining or other organs of digestion, soon sets up a condition that is beyond repair. In a less concentrated form, when this is not sufficiently strong to be corrosive, it exerts an irritant effect. In this form it may not do much harm unless taken in considerable quantity. When thus the mucous membrane of the stomach and intestines becomes inflamed pain and diarrhea are likely to result.
Treatment.—Any of the alkalies may be used as an antidote. Most convenient of these are chalk, baking soda, marble dust, magnesia, lime, soap, or plaster from a wall. Mucilaginous drinks should be given in large quantities.
Vegetable acids.—Oxalic acid in particular is corrosive in its action when taken in concentrated solution, losing its corrosive effect and becoming irritant when more dilute. It also exerts a specific effect on the heart, frequently causing death from syncope. Taken in the form either of the crystals or solution it is likely to cause death in a very short time. Failure of heart action and the attendant small pulse, weakness, staggering, and convulsions are the more noticeable symptoms. Acetic acid is irritant to the gastrointestinal tract, and may cause sudden paralysis of the heart.
Treatment.—The action of the acid should be counteracted by the use of alkalies, as advised above, by limewater or lime or plaster given promptly, by protectives to the digestive tract, and by stimulants.
POISONING BY ALKALIES.
The carbonates of potash and soda and the alkalies themselves in concentrated form cause symptoms of intestinal irritation similar to those produced by mineral acids. Ammonia, caustic soda, and caustic potash (lye) are those to which animals are most exposed. The degree of their caustic irritant effects depends on their degree of concentration. When they reach the stomach the symptoms are nearly as well marked as in the case of the acids. The irritation is even more noticeable, and purgation is likely to be a more prominent symptom. If death is not caused soon, the irritation of the gastrointestinal tract and malnutrition will last for a long time.
Treatment.—Treatment consists in neutralizing the alkali by an acid, such as dilute sulphuric acid (1 per cent) or strong vinegar. The administration of such an antidote and its action must be carefully watched during administration. In the chemical change which takes place when the acid and alkali are combined, carbonic-acid gas is liberated, which may be to an extent sufficient to cause considerable distention of the abdomen, and even to produce asphyxia from pressure forward on the diaphragm. Should this danger present itself, it may be averted by opening the flank, permitting the gas to escape. (See "Acute tympanites, or Bloating," [p. 22].) Flaxseed or slippery-elm decoction must be given to sooth the inflamed mucous surface. Opium may be used to allay pain.
COAL-OIL POISONING.
Coal oil is sometimes administered empirically as a treatment for intestinal parasites. If given in large doses it produces poisonous effects, which are likely to be manifested some time after the administration. It acts as an irritant to the digestive tract, causing dribbling of ropy saliva from the mouth, diarrhea, tenesmus, and loss of appetite, with increased temperature and cold extremities. Visible mucous membranes are injected, pupils of the eyes are contracted, and there is a watery discharge from the eyes and nostrils. Remotely it exerts a depressing influence on the functions of the brain and slight coma, and occasionally convulsions, from which the animal is easily aroused. The kidneys also suffer. The urine is dark colored and has the characteristic odor of coal oil. Death may result from gastroenteritis or convulsions.
Treatment.—The patient's strength should be fostered by the frequent administration of mild stimulants, of which aromatic spirits of ammonia is perhaps the best. The animal should be encouraged to eat soft feed and given mucilaginous drinks.
Crude coal oil is sometimes applied to the skin to kill parasites. If too much is used, especially in hot weather, great weakness and depression may be caused and in some cases death may result.
CARBOLIC-ACID POISONING.
Although one of the most valuable antiseptic remedies, carbolic acid in a concentrated form, when taken internally or used over a large surface externally, is likely to produce poisonous effects. It causes whitening, shrinking, and numbness of the structures with which it comes in contact, and, besides its irritant effect, exerts a powerful influence on the nervous system. Being readily absorbed, it produces its effect whether swallowed, injected into the rectum, inhaled, or applied to wounds, or even to a large tract of unbroken skin. Used extensively as a dressing, it may produce nausea, dizziness, and smoky or blackish colored urine. The last symptom is nearly always noticeable where the poisonous effect is produced. In more concentrated form, or used in larger quantities, convulsions, followed by fatal coma, are likely to take place. Even in smaller quantities, dullness, trembling, and disinclination for food often continue for several days. In a tolerably concentrated solution it coagulates albumen and acts as an astringent.
Treatment.—As an antidote internally, a solution of sulphate of soda or sulphate of magnesia (Glauber's or Epsom salt) may be given. The white of egg is also useful. Stimulants may be given if needed. When the poisoning occurs through too extensive applications to wounds or the skin, as in treatment of mange, cold water should be freely applied so as to wash off any of the acid that may still remain unabsorbed. As a surgical dressing a 3 per cent solution is strong enough for ordinary purposes. Water will not hold more than 5 per cent in permanent solution. No preparation stronger than the saturated solution should be used medicinally under any circumstances.
SALTPETER POISONING.
Both nitrate of soda and nitrate of potassium are poisonous to cattle. These substances are used for manure and for preserving meats. They may be administered in a drench by error in place of Glauber's salt, or they may be exposed within reach of cattle and thus be eaten. The toxic dose depends upon the condition of fullness of the stomach. If in solution and given on an empty stomach, as little as 3 ounces of saltpeter (nitrate of potassium) may be fatal to a cow. More of the Chile saltpeter (nitrate of soda) is required to cause serious trouble.
Symptoms.—Severe gastroenteritis, colic, tympanites, diarrhea, excessive urination, weakness, trembling, convulsions, collapse.
Treatment.—Same as for poisoning by common salt.
POISONING BY COMMON SALT.
A few pounds (3 to 5) of common salt will produce well-marked signs of poisoning in cattle. So much salt as this will not be taken by cattle except under unusual conditions. If the feed is poor in salt, and if no salt has been given for a long time, an intense "salt hunger" may occur that may lead an animal to eat a poisonous quantity, or an overdose of salt may be given by error as a drench. In order to prevent overeating of salt, it is doubtless better in salting cattle to use rock salt rather than that in more or less finely divided form.
Herring and mackerel brine and pork pickle are also poisonous, and are especially dangerous for hogs. In these substances there are, in addition to salt, certain products extracted from the fish or meat which undergo change and add to the toxicity of the solution. Sometimes saltpeter is present in such brines.
Symptoms.—The symptoms are great thirst, abdominal pain, diarrhea, poor appetite, redness and dryness of the mouth, increased urination, paralysis of the hind legs, weak pulse, general paralysis, coma, and death in from six to eight hours.
Treatment.—Allow as much warm water as the animal will drink; give protectives, such as linseed tea, etc. Linseed or olive oil may be given. To keep up the heart action give ether, alcohol, camphor, digitalis, or coffee. To allay pain, give opium.
VEGETABLE POISONS.
Vegetable poisons may be divided into two classes—those that are likely to be administered to the animal as medicine, and such as may be taken in the feed, either in the shape of poisonous plants or as plants or feeds of vegetable origin that have been damaged by fungi or by bacteria which have produced fermentation or putrefaction.
VEGETABLE POISONS USED AS MEDICINE.
OPIUM (MORPHIN, LAUDANUM) POISONING.
Opium and its alkaloid, morphia, are so commonly used in the practice of medicine that the poisonous result of an overdose is not uncommon. The common preparations are gum opium, the inspissated juice of the poppy; powdered opium, made from the gum; tincture of opium, commonly called laudanum; and the alkaloid or active principle, morphia. Laudanum has about one-eighth the strength of the gum or powder. Morphia is present in good opium to the extent of about 10 per cent. In medicine it is a most useful agent in allaying pain. It first produces a stimulating action, which is followed by drowsiness, a disposition to sleep or complete anesthesia, depending on the quantity of the drug used. In poisonous doses a state of exhilaration is well marked at first. This is particularly noticeable in cattle and in horses. The animal becomes much excited, and this stage does not pass into insensibility unless an enormous dose has been given. If the dose is large enough, a second stage sometimes supervenes, in which the symptoms are those of congestion of the brain. The visible membranes have a bluish tint (cyanotic) from interference with the air supply. The breathing is slow, labored, and later stertorous; the pupils of the eyes are very much contracted; the skin dry and warm. Gas accumulates in the stomach, so that tympanites is a prominent symptom. The patient may be aroused by great noise or the infliction of sharp pain, when the breathing becomes more natural. A lapse into the comatose condition takes place when the excitement ceases. Later, there is perfect coma and the patient can no longer be aroused from the insensible condition. The contraction of the pupil becomes more marked, the breathing intermittent and slower, there is perspiration, the pulse more feeble and rapid, till death takes place. Poisoning of cattle with opium or its products rarely goes beyond the stage of excitement, because the quantity of the drug required for the later effects is so great. Seventy-five grains of morphia administered subcutaneously has sufficed merely to excite for 12 hours.
Treatment.—Give strong coffee, 1 to 4 quarts, aromatic spirits of ammonia or carbonate of ammonia. Atropia is the physiological antidote.
STRYCHNIN POISONING.
Strychnin is a very concentrated poison and produces its effect very quickly, usually only a few minutes being necessary if given in sufficient dose and in such a way that it will be at once absorbed. When employed as a medicine, as a rule, minimum doses should be used, as cattle are quite susceptible to its effects and may be killed by the maximum doses given in the common manuals of veterinary medicine. The first noticeable symptom is evidence of unrest or mental excitement; at the same time the muscles over the shoulder and croup may be seen to quiver or twitch, and later there occurs a more or less well-marked convulsion; the head is jerked back, the back arched and leg extended, the eyes drawn. The spasm continues for only a few minutes, when it relaxes and another occurs in a short time. The return is hastened by excitement and in a short time again disappears, continuing to disappear and reappear until death results. As the poisonous effect advances the intervals between the spasms become shorter and less marked and the spasms more severe until the animal dies in violent struggles.
Treatment.—The best method is to put the patient under the influence of chloral, chloroform, or ether, and keep it there continuously until the effect of the poison has passed off. Alcohol may be given in large doses.
ACONITE POISONING.
In recent years tincture of aconite has become a popular stable remedy. If an animal is ailing, aconite is given whether indicated or not. Fortunately the dose used is generally small, and for this reason the damage done is much less than it would otherwise be. Aconite is one of the most deadly poisons known. It produces paralysis of motion and sensation, depresses the heart's action, and causes death by paralysis of respiration. In large doses it causes profuse salivation, champing of the jaws, and attempts at swallowing. If not sufficient to cause death, there is impaired appetite with more or less nausea for some time after. In poisonous doses it causes the animal to tremble violently, to lose power to support itself, and brings on slight convulsions, with perspiration. The pulse is depressed, irregular, and afterwards intermittent.
Treatment.—The chemical antidote is tannic acid, which forms an insoluble compound with the aconitin. The depressing effect on the heart should be counteracted by the use of ammonia, digitalis, alcohol, camphor, or other diffusible stimulants, which have a physiological effect opposite to aconite.
POISONOUS PLANTS.
An important group of poisons may be classed under this head. In most cases it is poison naturally belonging in the plant; in other cases the poisonous principle is developed in what would otherwise be harmless plants as a plant disease, or as a fermentation or putrefaction due to bacterial growth and observed in forage, grain, or meal that has become heated, damaged, or "spoilt."
The subject of poisonous plants is an important one and is of especial interest to those using the western stock ranges, for it is probable that there is no other single cause producing so many fatalities. In this article only a few of the more important plants are treated in a brief way, for an extended treatise would be necessary if the subject were to be handled adequately. Further information should be sought in the more elaborate publications. Many of the American poisonous plants have been treated in bulletins issued by the United States Department of Agriculture.
Treatment for plant poisoning.—Remedies given by the mouth in most cases fail to give relief to cattle affected by poisonous plants. The material of the poisonous plants in the first stomach is not very largely affected by a remedy given as a drench. If any beneficial result is effected, it must be on the material which has already passed into the fourth stomach, so that to get any real antidotal result the remedy must be given repeatedly in order to meet the alkaloid poisons as they are passing through the fourth stomach. While certain substances like tannic acid and potassium permanganate are the logical antidotes for plant poisons, in practical application they are very disappointing in the treatment of ruminant animals. Reliance must be mainly on prevention and upon such remedies as will increase elimination. A laxative or purgative is always helpful, and for this purpose Epsom salt may be given in pound doses, or linseed oil in doses of 1 or 2 pints. In some few cases special remedies can be given as is indicated below.
It is well to bear in mind that cattle while grazing freely in good pasture are not likely to eat poisonous plants to any extent. If these same plants are gathered and thrown in a pile, the animals, through a kind of pernicious curiosity, may eat them with disastrous results. This has frequently happened when freshly cut branches of cherry, yew, oleander, and other plants have been thrown where dairy cattle could get at them.
OAKS.
The foliage of oaks is a valuable constituent of the forage on many ranges and pastures. It has been shown, however, that when this is eaten without some admixture of other food, cattle frequently sicken and die. Many cases of the poisoning of cattle by acorns have been reported in England and Germany, and there have been some complaints in the United States. Harmful results from eating acorns do not seem likely to occur except as they are eaten in considerable quantities.
Symptoms.—The symptoms of oak poisoning are constipation, mucus and blood in the feces, emaciation, and edema. The symptoms of acorn poisoning are much the same.
Treatment.—Change of pasture or an addition of other food material.
HORSE CHESTNUT—BUCKEYE.
All the species of Æsculus, popularly known as horse chestnut or buckeye, are considered poisonous. The bark, leaves, and fruit are injurious. It is said that if the fruit is boiled or roasted and washed out it becomes harmless and even is a desirable addition to the feed of cattle. The Indians in time of scarcity of food have used the fruit after preparing it in this way. The buckeyes are said to have a specific effect in producing abortion in cattle and goats.
DEATH CAMAS (SPECIES OF ZYGADENUS).
The death-camas plants, which are commonly known in the Pacific States as "lobelia," are especially destructive of sheep, but cattle sometimes eat them and are poisoned. Cases of cattle poisoning are not likely to result fatally.
Symptoms.—The symptoms are salivation, nausea accompanied by vomiting, great weakness, and lowered temperature.
Treatment.—There is no effective treatment for death-camas poisoning.
FLY POISON (CHROSPERMA MUSCÆTORIUM).
This plant, which is closely related to the death-camas plants, is sometimes known as "stagger grass" and causes a considerable loss in the Southern States. It grows earlier than the grasses, and on this account is more likely to be eaten. Like death camas, it produces pronounced nausea, resulting in vomiting and weakness, and in cases which recover the effects may continue for several days. Apparently the injurious effects are more common in the case of cattle than in other domestic animals. There is no known way of treating these animals, though doubtless purgatives would be beneficial.
YEW (TAXUS BACCATA).
The European yew has long been known as a very poisonous plant. It is cultivated in America, and while cases of poisoning have not been common, it is well to recognize its dangerous character. A comparatively small dose is poisonous and ordinarily acts with great rapidity. It causes respiratory paralysis and the animal dies in convulsions.
LAUREL.
The laurels, including the broad-leafed laurel, Kalmia latifolia, the narrow-leafed laurel, Kalmia angustifolia, the rhododendrons, and other closely related plants are poisonous and cause considerable losses. It is dangerous to let cattle graze where these plants are abundant at times when other forage is scarce. The symptoms are salivation, nausea and vomiting, spasms, dizziness, stupor, and death.
FERN.
The common brake or bracken fern, Pteris aquilina, has been considered responsible for the poisoning of many horses and cattle. Many cases have been reported in England and Germany, and some well-authenticated cases in the United States. Very little has been learned experimentally of fern poisoning, but there seems to be little question that it has been the cause of many deaths. The symptoms are said to be temperature higher than normal, loss of appetite, bloody discharges from mouth, nose, and bowels, and great depression followed by coma and death. Some authors say that the urine is colored by blood. It is thought by some that the disease known as "red water" in the northwestern United States and Canada is caused by eating ferns.
SORGHUM POISONING.
Under certain conditions sorghum contains enough hydrocyanic acid to make it exceedingly dangerous to cattle. These cases of poisoning most commonly occur when cattle are pastured upon the young plant or upon a field where the crop has been cut and is making a second growth. Conditions of drought make the sorghum especially dangerous. There is some reason to think that the frosted second growth is particularly rich in hydrocyanic acid. The cases of poisoning occur when animals are grazed upon the plant, but not from the harvested crop or from silage. If cattle are grazed on sorghum or sorghum stubble they should at first be under constant observation and should be removed as soon as any signs of illness appear. Similar precautions should be used in grazing kafir.
CORNSTALK DISEASE.
Considerable losses of cattle have occurred when they were turned upon cornfields in the fall. Deaths come very suddenly and there is no opportunity to apply remedies. It has been thought that these fatalities, like those from sorghum, were caused by hydrocyanic acid, but there is good reason to think that this is not true, and at the present time there is no accepted explanation of this disease, although there seems to be no doubt that it is connected in some way with the condition of the corn. Whether a given field is poisonous or not can only be determined by experiment, and the wise farmer will keep his cattle under close observation when they are first turned into a cornfield.
WATER HEMLOCK (CICUTA).
This plant, growing in wet places by ditches and along creeks, is the most poisonous of North American plants. The root is the poisonous part, and cattle generally get it when it is plowed up or washed out by high water. Sometimes they pull it up, for the plant occasionally grows out into ditches so that the whole plant will be taken in grazing. The most marked symptoms of Cicuta poisoning are the violent convulsions, which remind one of the effect of strychnin.
Treatment.—Little can be done in the way of treatment. The logical thing is to attempt to control the convulsions by means of morphia, but in view of the fact that the stomach can not be emptied, the prognosis is not good, and most cases die.
LARKSPURS.
The larkspurs are a source of heavy loss to cattle owners in the higher ranges of the West. There are a number of species, growing at altitudes from 4,000 feet to timber line, and all are poisonous. A few cases of poisoning by larkspurs have been reported in the eastern United States, but most of the losses are confined to the West, both because larkspurs grow there in greater profusion and because cattle are grazed in that region on the open ranges. The losses are confined to cattle, for sheep and horses can graze on larkspur with no resulting harm. Most of the larkspur losses occur in the spring and early summer, as the plants lose their toxicity after maturing.
Symptoms.—Larkspur poisoning is accompanied by a definite line of symptoms. In range animals the first symptom noted is generally the sudden falling of the animal and consequent inability to rise. After a while it may rise, only to fall again. This may happen repeatedly. In severe cases the animal lies prone and exhibits nausea, accompanied by vomiting. It dies of respiratory paralysis, death many times being hastened by the asphyxia following the vomiting.
Treatment.—The animal, if found down, should be turned so that its head is uphill in order to relieve the lungs. Many cases will recover with no further treatment. Nearly all cases will recover if a hypodermic injection is given immediately of physostigmin salicylate 1 grain, pilocarpin hydrochlorid 2 grains, strychnin sulphate ½ grain.
LOCO.
The loco plants have caused especially heavy losses of cattle, horses, and sheep. They grow in the semiarid regions of the West and sometimes in great luxuriance. The best known are the "blue loco," the "woolly loco" or "purple loco," and the "white loco" or "rattle-weed." The blue loco is common in parts of New Mexico, Arizona, and Utah. It affects both horses and cattle. The purple loco, Astragalus mollissimus, is common in Texas and the adjoining States and extends north as far as Nebraska and Colorado. It is especially destructive to horses. The white loco, Oxytropis lamberti, is still more widely distributed, being found in the plains region from Alaska to Mexico and west of the Rocky Mountains to central Utah. The white loco is much more important than the purple loco, for it affects not only horses but cattle and sheep. These plants belong to the pea family, and there are a number of other species of this family that are loco plants and produce the same symptoms.
Symptoms.—Loco poisoning is a chronic condition and symptoms are shown only after somewhat prolonged feeding. The condition is one of cumulative poisoning, and animals sometimes decline very rapidly after the first symptoms appear. In many cases animals acquire a habit of eating loco and prefer it to any other feed. The poison affects the central nervous system. There is a lack of muscular coordination and the animal performs very erratic movements. In the later stages the animal becomes emaciated and eventually dies of starvation.
Treatment.—Locoed animals are badly constipated, and it is important that this condition should be remedied at the start. Any purgative can be used, but Epsom salt has been found especially effective. If locoed animals can be turned into a field of alfalfa, a large proportion of them will recover with no further treatment. Recovery may be aided by giving cattle, hypodermically, daily doses of three-twentieths to four-twentieths of a grain of strychnin. By this treatment cattle can be cured and put in condition for market.
WHITE SNAKEROOT (EUPATORIUM URTICÆFOLIUM).
White snakeroot, frequently known as "rich weed," is a plant growing in great abundance in some of the eastern and central regions of the United States. It is particularly abundant in parts of Ohio, Indiana, and Illinois, and in western North Carolina. It is responsible for most, if not all, of the cases of a disease which is commonly known as "milk sickness."
Symptoms.—The animals are constipated, sometimes have bloody feces, become weak, and exhibit muscular trembling. This trembling is very characteristic, so that the disease is sometimes known as "the trembles."
Remedy.—There are no remedies which will work very efficiently. It is desirable to give the animals purgatives like Epsom salt and, of course, to remove them from fields where this plant is abundant.
RAYLESS GOLDENROD (ISOCOMA WRIGHTII).
The rayless goldenrod is a plant growing in especial abundance in parts of the Pecos Valley in New Mexico and Arizona, and there produces a disease so much like that produced in the East by white snakeroot that it is sometimes called milk sickness. More generally this disease goes under the name of "alkali disease." The plant has produced heavy losses in the regions where it grows abundantly.
Symptoms.—The symptoms are much like those produced by the white snakeroot. The animals are constipated, sometimes have bloody feces, become weak, and exhibit muscular trembling. There is good reason to think, too, that the milk of cows eating this plant is more or less injurious.
Treatment.—A purgative like Epsom salt will aid an animal in recovering, but most important is to remove the cattle from pastures where the plant is abundant and give them an abundance of good forage. Under such conditions they are almost certain to recover.
MILKWEEDS.
Many of the milkweeds have long been known to have more or less poisonous properties. Within the last few years it has been discovered that certain of the milkweeds going under the popular name of whorled milkweeds are especially toxic. There are at least four species of whorled milkweeds, but two of them are particularly important from the standpoint of people handling livestock. One, known scientifically as Asclepias galioides, is harmful in Colorado, Utah, Arizona, and New Mexico, while another, known as Asclepias mexicana, has produced losses, especially in California and Nevada. These whorled milkweeds are distasteful to all animals and are eaten only when the stock is closely confined to pastures where there is little else in the way of forage.
Symptoms.—The most prominent symptoms are weakness, producing staggering, and this is followed in acute cases by violent spasms.
Treatment.—There is no treatment which will effectively antidote the effect of the poison. In practically all cases, however, poisoning may be avoided if care is taken to prevent animals from being closely confined where this plant is abundant, as they never eat the plant by choice.
CHERRY.
In the leaves of the cherries more or less hydrocyanic acid is produced, and when these leaves are eaten in any considerable quantity cases of poisoning are likely to arise. It is popularly supposed that these cases arise from eating wilted cherry leaves, but there is every reason to think that the fresh leaves will produce the same results. These cases are easily prevented, because no harm results from eating a small quantity of the leaves, and if the fact is recognized that poisoning may result from eating a large quantity, it is not difficult to care for the animals so as to prevent poisoning.
ERGOTISM.
The poisonous effects of ergot ([Pls. V], [VI]) appear chiefly in the winter and spring of the year and among cattle. It is developed among grasses grown on rich soil in hot, damp seasons. Rye seems more liable to ergot than any of our other crops. Of the grasses which enter into the composition of hay, bluegrass is the most likely to become affected. Ergot may also affect redtop, oats, grasses, and grains. On the plant the fungus manifests itself on the seeds, where it is easily recognized when the hay is examined in the mow. The ergotized seeds are several times larger than the natural seeds—hard, black, and generally curved in shape.
The effect of the protracted use of ergot in the feed is pretty well understood to be that of producing a degeneration and obstruction of the smaller arterial branches. The result is to shut off the blood supply to the distal parts of the body, where the circulation is weakest, and thus to produce a mummification or dry gangrene of the extremities, as the ears, tail, feet, etc. Cattle seem to be more susceptible than other animals to the influence of ergot, possibly on account of the slowness of the heart's action. When the effect of the poison has become sufficient to entirely arrest the circulation in any part, the structures soon die. The disorder manifests itself as lameness in one or more limbs; swelling about the ankle which may result in only a small slough or the loss of a toe, but it may circumscribe the limb at any point below the knee or hock by an indented ring below which the tissues become dead. The indentation soon changes to a crack, which extends completely around the limb, forming the line of separation between the dead and living structures. The crack deepens till the parts below drop off without loss of blood, and frequently with very little pus. Ergot may cause serious irritation of the digestive tract, or by acting upon the nervous system it may cause lethargy or paralysis. It also operates to cause contraction of the uterus, and may thus cause abortion.
Treatment.—Regarding the treatment, change of feed and local antiseptics are, of course, indicated. The former may be useful as a preventive, but when the symptoms have appeared the animal is necessarily so completely saturated that recovery is likely to be tedious. Tannin may be given internally in doses of one-half dram twice daily for a few days to neutralize the unabsorbed alkaloids of the ergot. At the same time give castor oil. To dilate the blood vessels give chloral hydrate. Bathe the affected parts with hot water. If sloughing has gone far, amputation must be resorted to.
OTHER POISONOUS FUNGI.
Many other fungi poison herbivora. In some instances, however, where fungi are blamed for causing disease their presence on the feedstuff or herbage is but coincidental with some other and more potent disease-producing factor. For example, if the conditions are favorable to the growth of fungi they are also favorable to the growth of bacteria, and bacteria may produce poisons in feeds. In general it may be said that any feed that is moldy, musty, or putrid is possibly dangerous. Silage, properly cured, does not belong to this class, because the curing of silage is not a bacterial process. But spoiled silage and silage matted with mold is dangerous and should not be fed.
POISONING BY ANIMAL PRODUCTS.
SNAKE BITES.
The poison contained in the tooth glands of certain venomous reptiles, particularly some of the snakes, which is injected into or under the skin of an animal bitten by the reptile, is a very powerful agent. It is likely to produce a serious local irritation, and in the case of the more poisonous snakes serious constitutional disturbances, even to causing death, which it may do in either of two ways: First, when very strong, by exerting a narcotic influence similar to that of some of the powerful poisons, checking heart action. Second, by diffused inflammation of the areolar tissue, gangrene, and extensive sloughing.
Symptoms.—The symptoms of snake bite are a local swelling caused by an intense local inflammation, pricks showing where the fangs penetrated, depression, weakness, feeble pulse, difficult breathing, bluish discoloration of the visible mucous membranes, stupor, or convulsions. If the poison is not powerful or plentiful enough to produce death, it is, at any rate, likely to cause severe local abscesses or sloughs.
Treatment.—The treatment may be divided into local and general. Locally every effort should be made to prevent absorption of the poison. If discovered at once the bitten part had better be excised. If that is impracticable and a ligature can be applied, as in the case of a bite to one of the limbs, no time should be lost in applying it above the injury. It should be made sufficiently tight to so far as possible arrest circulation in the bitten part. The wound should be freely incised, so that it will bleed freely, and the poison should be extracted by cupping, or pressed out by squeezing with the fingers. Permanganate of potassium in 5 per cent solution should be applied to and injected into the wound. The depressing effect of the poison on the general system should be counteracted by hypodermic injections of strychnin, or by liberal drenching with stimulants, such as coffee, digitalis, or the aromatic spirits or carbonate of ammonia. In animal practice the alcoholic stimulants and local treatment above described are likely to meet with best success. A special antitoxin for use in treating snake bite is now prepared and may be had from the leading druggists. It is quite effective if used promptly.
WASP AND BEE STINGS.
Wasps and bees secrete a poisonous substance which they are able to insert through the skin of an animal by the aid of their sharp stings. This poison is a severe local irritant and may even cause local gangrene. It also has a depressing effect upon the central nervous system and destroys the red-blood corpuscles. To produce these general effects it must be introduced in very large quantities, as when an animal is stung by a swarm of bees or wasps.
Treatment.—The treatment is to wash the parts with diluted ammonia or permanganate of potassium solution and to give stimulants internally. If there is so much swelling about the head and nostrils as to interfere with breathing, tracheotomy may be necessary.
POISONING WITH SPANISH FLY.
Spanish fly, in the form of powdered cantharides, may be given in an overdose, or when applied as a blister to too large a surface of skin enough may be absorbed to poison. If given by the mouth, it causes severe irritation of the gastrointestinal tract, shown by salivation, sore throat, colic, bloody diarrhea, etc. It also produces, whether given by the mouth or absorbed through the skin, irritation of the urinary tract, as shown by frequent and painful urination. If death results, it is due to respiratory paralysis.
Treatment.—Give protectives and the white of egg, with opium. Do not give oils or alcohol.
DISEASES OF THE HEART, BLOOD VESSELS, AND LYMPHATICS.
By W. H. Harbaugh, V. S.
[Revised by Leonard Pearson, B. S., V. M. D.]
THE CIRCULATORY SYSTEM.
In cattle, as in human beings, the heart, blood vessels, and lymphatics may be described as the circulatory apparatus.
The heart is in the thoracic cavity (chest). It is conical in form, with the base or large part uppermost, while the apex, or point, rests just above the sternum (breastbone). It is situated between the right and left lungs, the apex inclining to the left, and owing to this the heart beats are best felt on the left side of the chest, behind the elbow. The heart may be considered as a hollow muscle, containing four compartments, two on each side. The upper compartments are called auricles and the lower ones ventricles. The right auricle and ventricle are completely separated from the left auricle and ventricle by a thick septum or wall, so that there is no communication between the right and left sides of the organ.
At the bottom of each auricle is the auriculo-ventricular opening, each provided with a valve to close it when the heart contracts to force the blood into the arteries. In the interval between the contractions these valves hang down into the ventricles.
The muscular tissue of the heart belongs to that class known as involuntary, because its action is not controlled by the will.
The cavities of the heart are lined by a serous membrane, called the endocardium, which may be considered as a continuation of the veins and the arteries, forming their internal lining. The walls of the ventricles are thicker than those of the auricles, and the walls of the left ventricle are much thicker than those of the right.
The heart is enveloped by a fibrous sac (or bag), called the pericardium, which assumes much of the general shape of the outer surface of the heart.
The action of the heart is similar to that of a pump and its function is to keep the blood in circulation. The auricles may be considered as the reservoirs or receivers of the blood and the ventricles as the pump chambers. During the interval between contractions, the heart being in momentary repose, the blood pours into the auricles from the veins; the auriculo-ventricular orifices being widely open, the ventricles also receive blood; the auricles contract and the ventricles are filled; contraction of the ventricles follows; the auriculo-ventricular valves are forced up by the pressure of the blood and close the auriculo-ventricular openings and prevent the return of blood into the auricles; the contraction of the ventricles forces the blood from the right ventricle into the lungs through the pulmonary artery and its branches, and from the left ventricle into the aorta, thence through the arteries to all parts of the body. After the contraction of the ventricles the heart is again in momentary repose and is being filled with blood, while the valves in the aorta and pulmonary artery close to prevent the return of blood into the ventricles. (See [Pl. VII].)
The average weight of the heart of an ox is said to be from 3½ to 5 pounds; but, of course, owing to the many breeds and sizes of cattle, it must vary in different animals.
The vessels that convey the blood from the heart to all parts of the body are called arteries; those which return the blood to the heart are called veins. The arteries divide and subdivide (like the branches of a tree), become smaller and smaller, and ultimately ramify into every part of the body. Between the ultimate ramifications of the arteries and the beginning of the veins there is an intermediate system of very minute vessels called capillaries, which connect the arterial with the venous system of the circulation. The walls of the arteries are possessed of a certain amount of rigidity, sufficient to keep the tubes open when they are empty.
The blood leaves the left ventricle through a single vessel, the common aorta, consisting of the anterior and posterior aortas, which give off the large arteries.
The veins take the blood from the capillaries in all parts of the body. They begin in very small tubes, which unite to become larger in size and less in number as they approach the heart.
In its course an artery is usually accompanied with a vein and in many situations with a nerve. The more important arteries are placed deep within the body; when they are superficial, however, they are generally found where least exposed to injury, as, for example, on the inner side of the legs. Arteries are less numerous than veins, and their total capacity is much less than that of the veins. A great number of veins are in the tissue immediately beneath the skin and do not generally accompany arteries.
The blood, throughout its course in the heart, arteries, capillaries, and veins, is inclosed within these vessels. Except where the large lymphatics empty into the venous blood, there is no opening into the course of the blood.
All the arteries except the pulmonary and its branches carry bright-red blood, and all the veins, except the pulmonary veins, carry dark-red blood. The impure dark-red blood is collected from the capillary vessels and carried to the right auricle by the veins; it passes down into the right ventricle, and thence into the pulmonary artery and through its branches to the capillaries of the lungs, where the carbonic-acid gas and other impurities are given up to the air in the air cells of the lungs (through the thin walls between the capillaries and the air cells), and where it also absorbs from the air the oxygen gas necessary to sustain life. This gas changes it to the bright-red, pure blood. It passes from the capillaries to the branches of the pulmonary veins, which convey it to the left auricle of the heart; it then passes through the auriculo-ventricular opening into the left ventricle, the contraction of which forces it through the common aorta into the posterior and anterior aortas, and through all the arteries of the body into the capillaries, where it parts with its oxygen and nutritive elements and where it absorbs carbonic-acid gas and becomes dark colored. (See theoretical diagram of the circulation, [Pl. VII].)
The branches of certain arteries in different parts unite again after subdividing. This reuniting is called anastomosing, and assures a quota of blood to a part if one of the anastomosing arteries should be tied in case of hemorrhage, or should be destroyed by accident or operation.
THE BLOOD.
The various kinds of food, after being digested in the alimentary canal, are absorbed and carried into the blood by the lymphatics, and by the blood to the places where nutrition is required. The blood takes from all parts of the body all that is no longer required, and carries it to the different organs through which it is eliminated from the body. It contains within itself all the elements which nourish the body.
The blood may be considered as a fluid holding in solution certain inorganic elements and having certain bodies suspended in it. To facilitate description, the blood may be considered as made up of the corpuscles and the liquor sanguinis. The corpuscles are of two kinds, the red and the white, the red being the more numerous. The color of the blood is caused by the coloring matter in the red corpuscles, which are the oxygen carriers. Both kinds are very minute bodies, which require the aid of the microscope to recognize them. The liquor sanguinis is composed of water containing in solution salts, albumen, and the elements of fibrin.
The lymphatics, or absorbents, are the vessels which carry the lymph and chyle in the blood. They begin as capillaries in all parts of the body, gradually uniting to form larger trunks. Placed along the course of the lymphatic vessels are glands, in some situations collected into groups; for example, in the groin. These glands are often involved in inflammation arising from the absorption of deleterious matter.
Absorption is the function of the lymphatics. The liquor sanguinis passes from the blood capillaries to supply nutrition to the tissues. All of the liquor sanguinis that is not required is absorbed by the lymphatic vessels and conveyed back to the blood by the lymphatic ducts. The lymphatics which proceed from the intestines convey the chyle into the blood during digestion. As a rule, the lymphatic vessels follow the course of the veins. All the absorbent vessels convey their contents to the thoracic duct and right great lymphatic vein, which empty into the anterior vena cava, where the lymph and chyle mix with the venous blood, and thus maintain the supply of nutritive elements in the blood.
THE PULSE.
As fully explained, the heart pumps the blood throughout the arterial system. The arteries are always full and each contraction of the ventricle pumps more blood into them; this distends their elastic walls and sends along them a wave which gradually becomes less perceptible as it nears the very small arteries. This wave constitutes the pulse, and is lost before the capillaries are reached. The sensation or impression given to the finger when placed upon the artery shows the force exerted by the heart and some important facts concerning the condition of the circulation. In adult cattle the average number of pulsations in a minute is from 50 to 60. The pulse is faster than normal after exercise, excitement, on hot days, from pain, and as a result of fullness of the stomach. In old animals it is slower than in the young and in males slightly slower than in females. In fevers and inflammations and in local diseases of the heart the pulse rate is increased. If the rate is greater than 100 or 110 to the minute the outlook for recovery is not good.
Other variations of the pulse are known as infrequent pulse, which means that the number of pulsations in a given time is less than normal. The irregular or the intermittent pulse is when the pulsations do not follow in regular order. The large pulse and the small pulse refer to the volume of the pulse, which may be larger or smaller than usual. The strong pulse and the feeble pulse refer to the strength or weakness of the pulsation. The pulse is said to be hard when the vessel feels hard and incompressible, the soft pulse being the opposite. By dicrotic pulse is meant that kind of pulsation which makes each beat seem double, and therefore it is generally called the double pulse.
The venous or "jugular pulse" is the pulsation so frequently observed in the jugular vein of cattle and is particularly noticeable while they are ruminating—"chewing the cud." It is not always associated with disease, but may be a symptom of some disease of the heart; in such cases the jugular pulse is continuous.
The place selected for feeling the pulse in cattle is where the submaxillary artery winds around the lower jawbones, just at the lower edge of the flat muscle on the side of the cheek; or, if the cow is lying down, the metacarpal artery on the back part of the fore fetlock is very convenient for the purpose.
THE EXAMINATION OF THE HEART.
Corresponding to the beats of the heart two sounds are emitted which are of a definite type in healthy animals. The first is produced by the contraction of the heart and the flow of blood out of it; the second is caused by the rebound of blood in the aorta and the closure of the valves that prevent it from flowing backward into the heart, whence it came. The first sound is the longer and louder of the two, though of low pitch. The second sound is sharper and shorter, and is not always easy to hear. There is a brief interval between them.
To distinguish these sounds, the ear is placed against the left side of the chest, a little above the point where the elbow rests when the animal is standing in a natural position, and about opposite the sixth rib. Both heart sounds are reduced in intensity when the animal is weak or when the heart is forced away from the chest wall by collections of fluid or by tubercular or other growths. Nonrhythmical heart sound is often caused by pericarditis or by disease of the valves. It may also be attributable to overfilling of the heart upon the right side, as occurs in severe congestion of the lungs and in some febrile diseases.
In pericarditis, sounds like scraping, rubbing, or splashing may be heard, entirely apart from the two normal sounds above described.
The impulse of the heart, as felt by placing the hand against the chest, is of some consequence in reaching a conclusion in respect to disease of the heart; but it must be remembered that the impulse may be very much increased by diseases other than those of the heart, as, for example, inflammation of various organs, severe pains, etc. The impulse may be increased also (when disease does not exist) by work, exercise, fright, or any cause of excitement, or, in general, by anything that causes acceleration of the pulse.
The impulse of the heart may be felt and the sounds may be heard fairly well in lean cattle, but in fat ones it is difficult and often impossible to detect either impulse or sound with any degree of satisfaction.
PALPITATION.
When the impulse of the heart is excessive—that is, when it beats more or less tumultuously—the familiar expression "palpitation of the heart" is applied; by many it is called "thumps." The hand or ear placed against the chest easily detects the unnatural beating. In some cases it is so violent that the motion may be seen at a distance. Palpitation is but a symptom, and in many instances not connected with disease of the structure of the heart or its membranes. A badly frightened animal may have palpitation. When it comes on suddenly and soon passes away, it depends on some cause other than diseases of the heart; when it is gradually manifested, however, and becomes constant, although more pronounced at one time than another, heart disease may be suspected, especially if other symptoms of heart disease are present.
INJURY TO THE HEART BY FOREIGN BODIES.
Cattle are addicted to the habit of chewing and swallowing many objects not intended as articles of food. Every veterinarian of experience has met with instances to remind him of this, and it is well known to butchers. Among the great variety of things that have thus found their way into the stomachs of cattle the following have been noticed: Finger rings, knitting needles, old shoes, table knives, wood, pieces of leather, pieces of wire, buttons, hairpins, brushes, nails, coins, etc. The more sharply pointed objects sometimes penetrate the wall of the stomach, in some cases causing gastric irritation enough to produce indigestion, gradually work their way through the diaphragm toward the heart, pierce the pericardium (bag inclosing the heart), wound the heart, and thus prove fatal to the animal. Cases are recorded in which the foreign body has actually worked its way into one of the cavities of the heart. Instances are known, however, in which the object took a different course, and finally worked its way toward the surface and was extracted from the wall of the chest. While it is possible that the foreign body may pierce the wall at different parts of the alimentary canal, as it frequently does that of the rumen (paunch), it is thought that in most cases it passes through the wall of the reticulum (smaller honeycombed compartment, or second stomach) and is drawn toward the heart by the suctionlike action of the chest. Post-mortem examinations have demonstrated the course it pursued, as adhesions and other results of the inflammation it caused were plainly to be seen. All manner of symptoms may precede those showing involvement of the heart, depending upon the location of the foreign body and the extent of inflammation caused by it. Severe indigestion may occur; stiffness and difficulty in moving about owing to the prods of the sharp body following muscular contraction; pain on pressure over the front, lower, or right side of the abdomen; coughing and difficult, quick breathing. In most cases the foreign body does not penetrate to the heart, nor even to the pericardium.
Symptoms.—The symptoms are as follows: The animal is disinclined to move actively, the step is restricted and cautious, sudden motion causes grunting, the attitude is constrained, the feet are drawn somewhat together, the back is arched, the face has an anxious expression. If the disease is of several days' standing, there is likely to be soft swelling (edema) beneath the neck, in the dewlap, and under the chest, between the fore legs. Breathing is short and difficult; it may clearly be painful. The pulse is rapid, 80 to 120 per minute. The muscles quiver as though the animal were cold. Rumination and appetite are depressed or checked. The dung is hard, and to void it appears to cause pain. These symptoms usually develop gradually, and, of course, they vary considerably in different animals, depending upon the size and location of the foreign body and the irritation it causes.
As a matter of course, in such cases treatment is useless, but when it is possible to diagnose correctly the animal could be turned over to the butcher before the flesh becomes unfit for use; that is, before there is more than a little suppuration and before there is fever. Knowing that cattle are prone to swallow such objects, ordinary care may be taken in keeping their surroundings as free of them as possible.
PERICARDITIS.
Inflammation of the pericardium (heart bag) is often associated with pneumonia and pleurisy, rheumatism, and other constitutional diseases, or with an injury. It also occurs as an independent affection, owing to causes similar to those of other chest affections, as exposure to cold or dampness and changes of the weather.
Symptoms.—It may be ushered in with a chill, followed by fever, of more or less severity; the animal stands still and dull, with head hanging low, and anxiety expressed in its countenance. The pulse may be large, perhaps hard; there is also a venous pulse. The hand against the chest will feel the beating of the heart, which is often irregular, sometimes violent, and in other instances weak, depending in part upon the quantity of fluid that has transuded into the pericardial sac. The legs are cold, the breathing quickened and usually abdominal; if the left side of the chest is pressed on or struck, the animal evinces pain. There may be spasms of the muscles in the region of the breast, neck, or hind legs. After a variable time swelling may also appear in the legs and under the chest and brisket.
In those animals in which the heart sounds may be heard somewhat distinctly, the ear applied against the chest will detect a to-and-fro friction sound, corresponding to the beats of the heart. This sound is produced by the rubbing of the internal surface of the heart bag against the external surface of the heart. During the first stages of the inflammation these surfaces are dry, and the rubbing of one against the other during the contraction and relaxation of the heart produces this sound. The dry stage is followed by the exudation of fluid into the heart sac, and the friction is not heard until the fluid is absorbed sufficiently to allow the surfaces to come in contact again. But during the time the friction sound is lost a sound which has been called a "churning noise" may take its place.
The friction sound of pericarditis can not be mistaken for the friction sound of pleurisy if the examination is a careful one, because in the heart affection the sound is made in connection with the heart beats, while in the pleuritic affection the sound is synchronous with each respiration or breath of air taken in and expelled from the lungs.
Treatment.—When pericarditis is complicated with rheumatism or other diseases the latter must be treated as directed in the description of them. The animal must be kept in a quiet, comfortable place, where it will be free from excitement. Warm clothing should be applied to the body, and the legs should be hand-rubbed until the circulation in them is reestablished, and then they should be snugly bandaged. The food should be nutritive and in moderate quantity. Bleeding should not be performed unless the case is in the hands of an expert.
At the beginning give as a purgative Epsom salt—1 pound to an average-sized cow—dissolved in about a quart of warm water and administered as a drench. When there is much pain 2 ounces of laudanum, diluted with a pint of water, may be given every three hours until the animal is better. Do not give the laudanum unless demanded by the severity of the pain, as it tends to constipate. Give one-half ounce of nitrate of potassium (saltpeter), dissolved in drinking water, four or five times a day. After the attack has abated mustard mixed with water may be rubbed well over the left side of the chest to stimulate the absorption of the fluid within the pericardium. The other medicines may be discontinued and the following administered: Sulphate of iron, 2 ounces; powdered gentian, 6 ounces; mix and make 8 powders. Give one powder every day at noon, mixed with feed, if the animal will eat it, or shaken up with water in a bottle as a drench. Also the following: Iodid of potassium, 2 ounces; nitrate of potassium, 8 ounces; mix and make 16 powders. Give one in drinking water or in drench every morning and evening. The last two prescriptions may be continued for several weeks if necessary.
In extreme cases tapping the pericardium with a trocar and cannula to draw off the fluid is resorted to, but the operation requires exact anatomical knowledge.
After death from pericarditis there is always more or less fluid found in the pericardium; the surfaces are rough and covered with a yellow-colored exudate. There are also in many cases adhesions to a greater or less extent between the heart and pericardium.
MYOCARDITIS.
Inflammation of the muscular structure of the heart occurs in limited, circumscribed areas, as evidenced by post-mortem examination, and it is probably always somewhat involved in connection with pericarditis and endocarditis. It may readily be inferred that if the whole organ were inflamed death would ensue immediately. Usually myocarditis results from the preexistence of blood poisoning or of some infectious febrile disease.
Symptoms.—The chief symptoms are those of heart weakness. The heart beat is fast, weak, and often irregular. Respiration is difficult and rapid. There is great general weakness and depression. Death comes suddenly.
Treatment.—Treatment consists in supporting the animal by the use of stimulants, such as ammonia, coffee, digitalis, camphor, etc. Complete quiet must be provided, and the general care should be as in pericarditis.
ENDOCARDITIS.
When the membrane which lines the cavities of the heart—the endocardium— suffers inflammation, the disease is called endocarditis. The cause is another disease, during which substances that irritate the lining of the heart are produced and admitted into the circulation. These substances are usually living organisms, or it is possible that in some cases they are chemical irritants. Endocarditis occurs as a complication of or sequel to pneumonia, blood poisoning, inflammation of the womb, rheumatism, or severe wounds or abscesses. The symptoms are much the same as those of pericarditis, and it is difficult to discriminate between the two affections. There is a jugular pulse, the legs may become dropsical, and there is a tendency to faint if the head is elevated suddenly. The bellowslike sound is more distinct than it is in pericarditis. It is the most fatal of heart diseases, because of the liability of the formation of clots, which may adhere to the valves, change in the structure of the valves, and often a complication with an abnormal condition of the blood. Clots may be formed in the heart, and, being carried to other parts, prove fatal by interrupting the circulation in some vital organ.
Treatment similar to that advised for myocarditis may be followed in this disease.
VALVES OF THE HEART.
The valves are subject to abnormal growths and structural changes in chronic endocarditis or as a result of acute endocarditis. Sometimes valves are torn by sudden, extreme muscular effort or a congenital abnormality. Cases are also reported in which they have been found ruptured.
Symptoms.—The general symptoms are those of heart weakness, accompanied with edema and congestion of the lungs.
Treatment.—Relief is sometimes afforded, but usually only temporarily, by the use of stimulants, especially digitalis.
RUPTURE OF THE HEART.
Sudden effort, blows, or disease may lead to rupture of the heart of the ox. The first cause does not operate so often in cattle as in horses. Tuberculosis or ulceration from other causes, such as a foreign body, is the most common source of this accident. Rupture is shown by sudden fainting, followed very shortly by death.
HYPERTROPHY AND DILATATION OF THE HEART.
This is an enlargement of the heart, and may consist of the thickening of the walls alone, or at the same time the cavities may be either enlarged or diminished. Dilatation of the cavities has been noticed as existing independently of thickened walls. In hypertrophy the sounds of the heart are loud and pronounced, may be heard on both sides of the chest distinctly, and palpitation occurs to a greater or less extent. Fortunately both conditions are very rare in cattle.
ATROPHY.
Atrophy is the technical term for wasting of the muscular tissue. Atrophy of the heart is very rare among cattle, and is usually a result of other diseases.
FATTY DEGENERATION OF THE HEART.
This condition of the heart is met with in some very fat cattle, but it must be understood that the accumulation of fat around the heart is not referred to by this designation. In fatty degeneration the elements of the muscular tissue are replaced by fatty or oily granules. The muscle becomes weak, the heart contractions are insufficient, and heart weakness is shown by general weakness, shortness of breath, and weak, rapid pulse.
CYANOSIS.
Owing to the most prominent symptoms, cyanosis is also called "blue disease," and is seen occasionally in new-born calves. It is recognized by the blue color of the mucous membrane (easily seen by looking within the mouth and nostrils), the coldness of the surface of the body, and rapid, labored breathing. It is caused by non-closure of the foramen ovale, connecting the right with the left side of the heart, and the consequent mixing of the venous with the arterial blood. Calves so affected live but a short time.
MISPLACEMENT OF THE HEART.
Cases are recorded in which the heart has been found out of its natural position, sometimes even outside the chest. This is a congenital condition for which there is no remedy. A heifer calf with the heart entirely outside the thoracic cavity and beneath the skin in the lower part of the neck was kept for two years at the veterinary hospital of the University of Pennsylvania, during which time it grew to be a well-developed cow.
WOUNDS OF ARTERIES AND VEINS.
When a blood vessel is opened a glance will tell whether it is an artery or a vein by simply remembering that bright-red blood comes from arteries and dark-red from veins. When a vein or a very small artery is severed the blood flows from the vessel in a continuous and even stream, but when one of the larger arteries is severed the blood comes in intermitting jets or spurts corresponding to the beats of the heart. It is well to call attention to the fact that the dark-red blood which flows or oozes from a wound soon becomes bright red, because it gives up its carbonic-acid gas to the air, and absorbs oxygen gas from the air, which is exactly the change it undergoes in the capillaries of the lungs.
The general treatment of wounds will be found in another section; here it is necessary only to refer briefly to some of the most practical methods used to arrest hemorrhages, as instances occur in which an animal may lose much strength from the loss of blood, or even bleed to death unless action is prompt.
BLEEDING (HEMORRHAGE).
The severity of a hemorrhage depends upon the size of the vessel from which the blood escapes, though it may be stated that it is more serious when arteries are severed. If the wound in an artery is in the direction of its length, the blood escapes more freely than if the vessel is completely severed, because in the latter instance the severed ends retract, curl in, and may aid very much in arresting the flow. When the blood merely oozes from the wound, and even when it flows in a small stream, the forming of the clot arrests the hemorrhage in a comparatively short time.
Slight hemorrhages may be checked by the continuous application of cold water, ice, or snow, to the wound, as cold causes contraction of the small vessels. Water from a hose may be thrown on a wound, or dashed on it from the hand or a cup, or folds of cotton cloths may be held on it and kept wet. Ice or snow may be held against the wound, or they may be put into a bag and conveniently secured in position.
Hot water of an average temperature of 115° to 120° F. injected into the vagina or womb is often efficient in arresting hemorrhages from those organs. Tow, raw cotton, lint, or sponges may be forced into a wound and held or bound there with bandages. This is an excellent method of checking the flow of blood until the arrival of an expert. If the flow persists, these articles may be saturated with tincture of iron, but it is not advisable to use it unless necessary, as it is a caustic and retards healing by causing a slough. In cases of necessity, the articles may be saturated with vinegar, or tannic acid or alum dissolved in water may be used instead. Whatever article is used should be left in the wound sufficiently long to make sure that its removal will not be followed by a renewal of the hemorrhage. Sometimes it must remain there one or two days.
An iron heated white and then pressed on the bleeding vessel for three or four seconds is occasionally used. It should not be applied longer, or else the charred tissue will come away with the iron and thus defeat the purpose of its application.
Compression may be applied in different ways, but only the most convenient will be mentioned. To many wounds bandages may easily be applied. The bandages may be made of linen, muslin, etc., sufficiently wide and long, according to the nature of the wound and the region to be bandaged. Bed sheets torn in strips the full length make excellent bandages for this purpose. Cotton batting, tow, or a piece of sponge may be placed on the wound and firmly bound there with the bandages.
Many cases require ligating, which is almost entirely confined to arteries. A ligature is a piece of thread or string tied around the vessel. Veins are not ligated unless very large (and even then only when other means are not available) on account of the danger of causing phlebitis, or inflammation of a vein. The ligature is tied around the end of the artery, but in some instances this is difficult and it is necessary to include some of the adjacent tissue, although care should be taken not to include a nerve. To apply a ligature, it is necessary to have artery forceps (tweezers or small pincers may suffice) by which to draw out the artery in order to tie the string around it. To grasp the vessel it may be necessary to sponge the blood from the wound so that the end will be exposed. In case the end of the bleeding artery has retracted, a sharp-pointed hook, called a tenaculum, is used to draw it out far enough to tie. The ligature should be drawn tightly, so that the middle and internal coats will be cut through.
Another method of checking hemorrhage is called torsion. It consists in catching the end of the bleeding vessel, drawing it out a little, and then twisting it around a few times with the forceps, which lacerates the internal coats so that a check is effected. This is very effectual in small vessels, and is to be preferred to ligatures, because it leaves no foreign body in the wound. A needle or pin may be stuck through the edges of the wound and a string passed around between the free ends and the skin ([Pl. XXVII], fig. 10), or it may be passed around in the form of a figure 8, as is often done in the operation of bleeding from the jugular vein.
ANEURISM.
A circumscribed dilatation of an artery, constituting a tumor which pulsates synchronously with the beats of the heart, is called aneurism. It is caused by disease and rupture of one or two of the arterial coats. The true aneurism communicates with the interior of the artery and contains coagulated blood. It is so deeply seated in cattle that treatment is out of the question. Such abnormalities are ascribable to severe exertion, to old age, to fatty or calcareous degeneration, or to parasites in the blood vessels. Death is sudden when caused by the rupture of an aneurism of a large artery, owing to internal hemorrhage. Sometimes spontaneous recovery occurs. As a rule no symptoms are caused in cattle by the presence of deep-seated aneurisms, and their presence is not known until after death.
A false aneurism results from blood escaping from a wounded artery into the adjacent tissue, where it clots, and the wound, remaining open in the artery, causes pulsation in the tumor.
THROMBOSIS (OBSTRUCTION) OF THE ARTERIES.
Arteries become obstructed as a result of wounds and other injuries to them, as those caused by the formation of an abscess or the extension of inflammation from surrounding structures to the coats of an artery. Arteries are also obstructed by the breaking off of particles of a plug or clot, partly obstructing the aorta or other large artery. These small pieces (emboli) are floated to an artery that is too small to permit them to pass and are there securely held, producing obstruction. These obstructions are shown by loss of power in the muscles supplied by the obstructed artery and by excitation of the heart and by respiration after exercise. The loss of power may not come into evidence until after exercise.
Symptoms.—While standing still or when walking slowly the animal may appear to be normal, but after more active exercise a group of muscles, a leg, or both hind legs, may be handled with difficulty, causing lameness, and later there is practically a local paralysis. These symptoms disappear with rest. In some cases the collateral circulation develops in time, so that the parts receive sufficient blood and the symptoms disappear.
INFLAMMATION OF VEINS (PHLEBITIS).
When bleeding is performed without proper care or with an unclean lancet, inflammation of the vein may result, or it may be caused by the animal rubbing the wound against some object. When inflammation follows the operation, the coats of the vein become so much enlarged that the vessel may be felt hard and knotted beneath the skin, and pressure produces pain. A thin, watery discharge, tinged with blood, issues from the wound. The blood becomes coagulated in the vessel. In inflammation of the jugular the coagulation extends from the wound upward to the first large branch. Abscesses may form along the course of the vein. The inflammation is followed by obliteration of that part in which coagulation exists. This is of small import, as cattle have an accessory jugular vein which gradually enlarges and accommodates itself to the increased quantity of blood it must carry.
Treatment.—The treatment for inflammation of the vein is to clip the hair from along the course of the affected vessel and apply a blister, the cerate of cantharides. Abscesses should be opened as soon as they form, because there is a possibility of the pus getting into the circulation.
In the operation of bleeding the instruments should be clean and free from rust. If the skin is not sufficiently opened, or when closing the wound the skin is drawn out too much, blood may accumulate in the tissue, and if it does it should be removed by pressing absorbent cotton or a sponge on the part. Care should also be used in opening the vein, so that the instrument may not pass entirely through both sides of the vein and open the artery beneath it.