The part of the foetus that presents itself for entrance into the pelvic cavity and its position are of the greatest importance in giving birth to the young. Either end of the foetus, or its middle portion may be presented for entrance. Theanteriorandposterior presentationsmay be modified by the position that the foetus assumes. It may be in a position that places the back or vertebrae opposite the upper portion of the inlet, or the floor or sides of the pelvic cavity. These positions may be modified by the position of one or both limbs, or the head and neck being directed forwards instead of backwards. In thetransverse presentations, the back, or the feet and abdomen of the foetus may present themselves for entrance to the pelvic cavity. These presentations may show three positions each. The head may be opposite the upper walls of the inlet, the foetus assuming a dog-sitting position, or it may lie on either side.
In order to overcome the friction between the foetus and the wall of the maternal passages, these parts are lubricated by the fluids that escape from the "water bags." If birth is prolonged and the passages become dry, birth is retarded. The hair offers some resistance in a posterior presentation. Young mares that become hysterical have abnormal labor pains that seem to hold the foetus in the womb instead of expelling it.
CARE OF THE MOTHER AND YOUNG.—Although birth is generally easy in the different domestic animals, it may be difficult and complicated, and it is of the greatest economic importance that special attention be given the mother at this time. It is very necessary for her to be free if confined in a stall. If running in a pasture or lot, the necessary shelter from storms, cold or extreme heat should be provided. Other farm animals, such as hogs, horses and cattle, should not be allowed to run in the same lot or pasture.
When parturition commences, the mother should be kept under close observation. If the labor is difficult and prolonged, we may then examine the parts and determine the cause of the abnormal birth. Unnecessary meddling is not advisable. Before attempting this examination, the hands should be cleaned and disinfected, and the finger nails shortened if necessary. The different conditions to be determined are the nature of the labor pains, the condition of the maternal passages, and the position and presentation of the foetus. In the smaller animals this examination may be difficult. In prolonged labor the parts may be found dry and the labor pains violent and irregular, or weak. The foetus may be jammed tightly into the pelvic inlet, it may be well forward in the womb, the head and fore or hind limbs may be directed backwards, or one or more of these parts may be directed forward in such a position as to prevent the entrance of the foetus into the pelvic inlet. Sometimes the foetus is in a transverse position. The parts that present themselves at the pelvic inlet should be carefully examined and their position determined. The necessary assistance should then be given. Any delay in assisting in the birth may result in the death of the young or mother, or both. On the other hand, unintelligent meddling may aggravate the case and render treatment difficult or impossible. There is no line of veterinary work that requires the attention of a skilled veterinarian more than assisting an irregular or abnormal birth.
The attendant must guard against infecting the parts with irritating germs, or irritating and injuring them in any way. The hands, instruments, and cords must be freed from germs by washing with a disinfectant, or sterilization with heat. The quarters must be clean in order to prevent contamination of the instruments and clothing of the attendant by filth. Extreme force is injurious. For illustration, we may take a case of difficult birth caused by an unusually large foetus. Both presentation and position are normal, the forefeet and head having entered the pelvic cavity, but the shoulders and chest are jammed tightly in the inlet, and the progress of the foetus along the maternal passages is retarded. By using sufficient force, we may succeed in delivering the young, but by pulling on one limb until the shoulder has entered the pelvis, and repeating this with the opposite limb we are able to deliver the young without exposing the mother to injury. It may be necessary to change an abnormal presentation, or position, to a normal presentation, or as nearly normal as possible. This should be done before any attempt is made to remove the foetus.
Following birth the mother should not be unnecessarily disturbed. The quarters should be clean, well bedded and ventilated, but free from draughts. If the parturition has been normal, a small quantity of easily digested feed may be fed. If weak and feverish, feed should be withheld for at least twelve hours. The mare should be rested for a few weeks. The young needs no special attention if it is strong and vigorous, but if weak, it may be necessary to support it while nursing, or milk the mother and feed it by hand. If the mother is nervous and irritable, it may be necessary to remove the young temporarily to a place where she can hear and see it, until a time when she can be induced to care for it. The principal attention required for young pigs is protection against being crushed by the mother. The cutting off and ligation of the umbilical cord at a point a few inches from the abdomen, and applying tincture of iodine or any reliable disinfectant is very advisable in the colt and calf.
RETENTION OF THE FETAL MEMBRANES.—The foetus is enveloped by several layers of membranes. Theexternal envelope, the chorion, is exactly adapted to the uterus. Theinnermost envelope, the amnion, encloses the foetus. Covering the external face of the amnion and lining the inner face of the chorion is a double membrane,the allantois. The envelopes mentioned are not the only protection that the foetus has against injury. It is enveloped in fluids as well. Immediately surrounding it is theliquor amnii, and within allantois is theallantoic fluid.
[Illustration: FIG. 19.—Placenta of cow.]
The placentais a highly vascular structure spread out or scattered over the surface of the chorion and the mucous membrane of the uterus, that attaches the foetus and its envelopes to the womb (Fig. 19). It is by means of this vascular apparatus that the foetus is furnished with nourishment. The fetal and maternal placentas are made up of vascular villi and depressions that are separated only by the thin walls of capillaries, and a layer of epithelial cells. This permits a change of material between the fetal and maternal circulation. The arrangement of the placenta differs in the different species. In the mare and sow, the villi are diffused. In ruminants, the villi are grouped at certain points. These vascular masses are termed cotyledons. The maternal cotyledons or "buttons" form appendages or thickened points that become greatly enlarged in the pregnant animal.
Toward the end of the pregnant period, the attachments between the fetal and maternal placentulae undergo a fatty degeneration and finally separate. This results in contractions of the muscular wall of the uterus, and the expulsion of the foetus and its envelopes. In the mare, it is not uncommon for the colt to be born with the covering intact. This does not occur in the cow. Usually the envelopes are not expelled until a short time after birth in all animals, and it is not uncommon for them to be retained. This complication is most commonly met with in the cow.
In the mare theretention of the fetal envelopesor "afterbirth" is commonly due to the muscles of the womb not contracting properly following birth. Abortion, especially the infectious form, is commonly complicated by a retention of the fetal membranes. Any condition that may produce an inflammation of the lining membrane of the womb may result in retention of the "after-birth." Injuries to the uterus resulting from the animal slipping, fighting and becoming crowded are, no doubt, common causes of failure to "clean" in cows.
The symptomsare so marked that a mistaken diagnosis is seldom made. A portion of the membranes is usually seen hanging from the vulva, and the tail and hind parts may be more or less soiled. The latter symptom is especially prominent if the membranes have been retained for several days, and decomposition has begun. In such case, the discharge from the vulva is dark in color, contains small pieces of the decomposed membrane and has a very disagreeable odor. In the mare, acute inflammation of the womb may result if the removal of the "after-birth" is neglected. Loss of appetite, abnormal body temperature, weakness and diarrhoea may follow. Such cases usually terminate in death. Retention of the fetal membranes is a very common cause of leucorrhoea.
The treatmentconsists in removing the fetal envelopes before there is any opportunity for them to undergo decomposition. In the mare, this should be practised within a few hours after birth has occurred, and in other animals, from one to forty-eight hours. In warm stables and during the warm weather, treatment should not be postponed later than twenty-four hours. The only successful method of treatment is to introduce the hand and arm into the uterus, and break down the attachments with the fingers. In the larger animals, the use of the arm must not be interfered with by clothing. Every possible precaution should be taken to prevent infection of the genital organs with irritating germs. It is advisable in most cases to flush out the womb with a one per cent water solution of liquor cresolis compound after the removal of the fetal envelopes.
LEUCORRHOEA.—This is a chronic inflammation of the mucous membrane lining the genital tract, that is associated with more or less of a discharge from the vulva. It is common in animals that abort, or retain the "after-birth."
The discharge may be white, sticky, albuminous, and without odor, or it may be chocolate colored and foul smelling. The tail and hind parts are usually soiled with it. In chronic inflammation of the womb the discharge is intermittent. In mild cases the health of the animal is in no way impaired. Sterility is common. Loss of appetite and unthriftiness occur in severe cases.
Treatment.—Mild cases readily yield to treatment. This consists in irrigating the maternal passages with a one-half per cent warm water solution of liquor cresolis compound. This treatment should be repeated daily and continued for as long a time as necessary.
MAMMITIS.—Inflammation of the mammary gland or udder is more common in the cow than in any of the other domestic animals. In all animals it is most frequently met with during the first few weeks after birth.
A predisposing causein the development of mammitis is a high development of the mammary glands. The followingdirect causesmay be mentioned: incomplete milking, or milking at irregular intervals; injury to the udder by stepping on the teat; blows from the horns and pressure caused by lying on a rough, uneven surface; chilling of the udder by draughts and lying on frozen ground; and infection of the glandular tissue byirritating germs. The latter cause produces the most serious, and, sometimes, a very extensive inflammation. This form of inflammation may spread from one cow to another, causing the milk to be unfit for food, and bringing about the loss of one or more quarters of the udder.
The symptomsoccurring in the different forms of mammitis differ. The inflammation may involve one or more of the glands, and may affect either the glandular or the connective tissue. In some cases the gland may appear congested for a few days before the inflammatory changes occur. The part becomes hot, swollen, tender and reddened. It may feel doughy or hard. If the connective tissue is involved (interstitial form), there is apt to be a high body temperature, the udder may be much larger than normal, is tender and pits on pressure. Loss of appetite usually accompanies this form of mammitis. Very little or no milk is secreted. Sometimes, the milk is greatly changed in appearance, is foul smelling and contains pus. In congestion of the udder and rupture of the capillary vessels, the milk may contain blood.
Mild inflammation of the udder responds readily to treatment. The interstitial form may terminate in abscesses and gangrene. The replacement of the glandular tissue by fibrous tissue in one or more quarters is not uncommon. Death seldom occurs.
The preventive treatmentconsists in avoiding conditions that may favor or cause an inflammation of the gland. Animals that have highly developed mammary glands should be fed a light diet just before and following parturition. Following parturition, a dose of Epsom or Glauber's salts may be given. If the young does not take all the milk, the udder should be milked out as clean as possible. Massaging the udder by kneading or stroking may be practised.
The followingtreatmentis recommended: The application of a thick coating of antiphlogistin once or twice daily is a useful remedy. If the udder becomes badly swollen, it should be supported with a bandage. Extensive inflammation may be treated by the application of cold in the form of packs of cracked ice. Irrigating the gland with a four per cent water solution of boric acid is an important treatment for certain forms of mammitis. Abscess formation or suppuration should be promptly treated by opening and treating the abscesses. If gangrene occurs, it may be necessary to remove a part, or the whole of the udder.
The giving of milk discolored with blood may be treated by applying camphorated ointment twice daily.
SORE AND WARTY TEATS.—Irritation to the teats by filth, cold, moisture and injuries cause the skin to become inflamed, sore and scabby.
Preventive treatmentis the most satisfactory. Sore teats may be treated by applying the following ointment after each milking: vaseline ten parts and oxide of zinc one part. Pendulous warts may be clipped off with a sharp pair of scissors. Castor oil applied to the wart daily by rubbing may be used for the removal of flat warts.
"MILK-FEVER" OR POST-PARTUM PARALYSIS.—This is a disease peculiar to cows, especially heavy milkers that are in good condition. It most commonly occurs after the third, fourth and fifth calving. The disease usually appears within the first two or three days after calving, but it has been known to occur before, and as late as several weeks after calving. The cause is not certainly known. The Schmidt theory is that certain toxins are formed in the udder, owing to the over activity of the cells of the glandular tissue.
[Illustration: FIG. 20.—A case of milk-fever.]
The symptomsare characteristic of the disease. At the very beginning of the attack the cow stops eating and ruminating, becomes uneasy, switches the tail, stamps the feet, trembles, staggers when forced to walk and finally falls and is unable to get up. At first she may lie in a natural position; later, as the paralytic symptoms become more pronounced, the head is laid against the side of the body and the animal seems to be in a deep sleep (Fig. 20). In the more severe form the cow lies on her side, consciousness is lost and the paralysis of the muscles is marked. The different body functions are interfered with; the urine is retained, bloating occurs, respirations are slow, pulse weak and temperature subnormal or normal.
Preventive treatment, such as feeding a spare diet during the latter period of pregnancy, is not always advisable. Heavy milkers should be given one-half pound of Glauber's salts a day or two before calving, and the dose repeated when the cow becomes fresh. Cows affected with milk-fever seldom die if treated promptly.
Thetreatmentconsists in emptying the udder by milking and injecting air or oxygen gas into the gland until it is completely distended (Fig. 21). The milk-fever apparatus should be clean, and the air injected filtered. Before introducing the milking tube into the milk duct, the udder should first be washed with a disinfectant, and a clean towel laid on the floor for the gland to rest on. After injecting the quarter, strips of muslin or tape should be tied around the ends of the teats to prevent the escape of the air. If the cow does not show indications of recovery in from four to five hours, the treatment should be repeated.
[Illustration: FIG. 21.—Milk-fever apparatus: pump; filter; rubber tubing; and milk tube.]
It is very necessary to give the cow a comfortable stall and protect her from any kind of exposure. No bulky drenches should be administered. If she lies stretched out, the fore parts should be raised by packing straw under her. This is necessary in order to prevent pneumonia, caused by regurgitated feed entering the air passages and lungs. It is very advisable to give her the following mixture for a few days after the attack: tincture of nux vomica two ounces, and alcohol six ounces. One ounce of this mixture may be given four times daily in a little water.
1. Name the generative organs of the female.
2. Name the generative organs of the male.
3. Give the causes of sterility or impotency in the male and female.
4. Give the treatment of impotency in the male and female.
5. Describe the probable signs of pregnancy; positive signs of pregnancy.
6. Describe the hygienic care of the pregnant female in a general way.
7. Name the different forms of abortion; give the causes.
8. Describe the preventive treatment of infectious abortion.
9. Give a general discussion of the physiology of parturition.
10. What are the common causes of difficult birth?
11. What parts of the foetus may present themselves at the inlet of the pelvic cavity? What are the different positions of the foetus?
12. What attention should be given the mother at the time of parturition?
13. What attention should be given the young immediately after birth?
14. Give the causes of retention of the fetal membranes; state the method of removing them.
15. Give the causes and treatment of inflammation of the udder.
16. Give the cause of milk-fever; give the treatment.
GENERAL DISCUSSION.—The respiratory apparatus may be divided into two groups of organs, anterior and posterior. The anterior group, thenostrils, nasal cavities, pharynx, larynxandtrachea, is situated in the region of the head and neck. The posterior group, thebronchial tubesandlungs, is situated in the chest or thoracic cavity.
The nostrilsare the anterior openings of the air passages. The nasal cavities are situated in the anterior region of the head, and extend the entire length of the face. Each cavity is divided into three long, narrow passages by the two pairs of turbinated bones. The lining membrane is the nasal mucous membrane, the lower two-thirds or respiratory portion differing from the upper one-third, in that the latter possesses the nerve endings of the olfactory nerve and is the seat of smell. The five pairs of head sinuses communicate with the nasal cavities. Posteriorly and near the superior extremity of the nasal passages, are two large openings, the guttural, that open into the pharyngeal cavity.
The pharynxis a somewhat funnel-shaped cavity. The walls are thin and formed by muscles and mucous membrane. This is the cross-road between the digestive and respiratory passages. In the posterior portion of the cavity there are two openings. The inferior opening leads to the larynx and the superior one to the oesophagus. All feed on its way to the stomach must pass over the opening into the larynx. It is impossible, however, for the feed to enter this opening, unless accidentally when the animal coughs. The cartilage closing this opening is pressed shut by the base of the tongue when the bolus of feed is passed back and into the oesophageal opening.
The larynxmay be compared to a box open at both ends. The several cartilages that form it are united by ligaments. It is lined by a mucous membrane. The posterior extremity is united to the first cartilaginous ring of the trachea. The anterior opening is closed by the epiglottis. Just within is a V-shaped opening that is limited laterally by the folds of the laryngeal mucous membrane, the vocal chords.
The tracheais a cylindrical tube originating at the posterior extremity of the larynx, and terminating within the chest cavity at a point just above the heart in the right and left bronchial tubes. It is formed by a series of cartilaginous rings joined together at their borders by ligaments and lined by a mucous membrane.
The bronchial tubesresemble the trachea in structure. They enter the lungs a short distance from their origin, where they subdivide into branches and sub-branches, gradually decreasing in calibre and losing the cartilaginous rings, ligaments and muscular layer until only the thin mucous membrane is left. They become capillary in diameter, and finally open into the infundibula of the air cells of the lungs.
The lungstake up all of the space in the thoracic cavity not occupied by the heart, blood-vessels and oesophagus. This cavity resembles a cone in shape that is cut obliquely downwards and forward at its base. The base is formed by the diaphragm which is pushed forward at its middle. It is lined by the pleura, a serous membrane, that is inflected from the wall over the different organs within the cavity. The median folds of the pleura divide the cavity into right and left portions. A second method of describing the arrangement of the pleura is to state that it forms two sacks, right and left, that enclose the lungs. The lungs are the essential organs of respiration. The tissue that forms them is light, will float in water, is elastic and somewhat rose-colored. Each lung is divided into lobes, and each lobe into a great number of lobules by the supporting connective tissue. The lobule is the smallest division of the lung and is formed by capillary bronchial tubes, air cells and blood-vessels. It is here that the external respiration or the exchange of gases between the capillaries and the air cells occurs.
VENTILATION.—It is agreed by all persons who have investigated the subject, that unventilated stable air is injurious to animals. At one time it was believed that the injurious effects resulting from the breathing of air charged with gases and moisture from the expired air and the animal's surroundings, were due to a deficiency in oxygen. It is now believed that the ill-effects are mainly due to the stagnation of air, the humid atmosphere, and the irritating gases emanating from the body excretions.
The common impurities found instable airare carbonic and ammonia gas, moisture charged with injurious matter and dust from the floor and bodies of the animals. As a rule, the more crowded and filthy the stable, the more impurities there are in the air. If any of the animals are affected with an infectious disease, such as tuberculosis or glanders, the moisture and dust may act as carriers of the disease-producing germs. Infectious diseases spread rapidly in crowded, poorly ventilated stables. The two factors responsible for this rapid spread of disease are the lowered vitality of the animal, due to breathing the vitiated air, and the greater opportunity for infection, because of the comparatively large number of bacteria present in the air.
The purpose of stable ventilationis to replace the stable air with purer air. The frequency with which the air in the stable should be changed depends on the cubic feet of air space provided for each animal, and the sanitary conditions present. The principal factor in stable ventilation is the force of the wind. In cold weather it is very difficult to properly ventilate a crowded stable without too much loss of animal heat and creating draughts.
For practical purposes, theneed of ventilationin a stable can be determined by the odor of the air, the amount of moisture present and the temperature. It is impossible to keep the air within the stable as pure as the atmosphere outside.
All dangers from injury by breathing impure air, or by draughts can be eliminated by proper stable construction, attention to the ventilation and keeping the quarters clean.
[Illustration: FIG. 22.—A case of catarrhal cold.]
CATARRH (COLD IN THE HEAD).—Catarrh is an inflammation of the mucous membrane lining the nasal cavities that usually extends to the membrane lining of the sinuses of the head. It may be acute or chronic. The inflammation very often extends to the pharynx and larynx. Cold in the head is more common in the horse than in any of the other animals (Fig. 22).
The most common causesof "colds" are standing or lying in a draught, becoming wet, and exposure to the cold. "Colds" are common during cold, changeable weather. Horses that are accustomed to warm stables, are very apt to take "cold" if changed to a cold stable and not protected with a blanket. Most animals are not affected by the cold weather if given dry quarters and a dry bed. Irritation to the mucous membrane by dust, gases and germs is a common cause. Influenza and colt distemper are characterized by an inflammation of the respiratory mucous membranes. In the horse, chronic catarrh is commonly caused by diseased teeth, and injuries to the wall of the maxillary sinus. In sheep, the larvae of the bot-fly may cause catarrh.
The early symptomsusually pass unnoticed by the attendant. The lining membrane of the nostrils is at first dry and red. During this stage sneezing is common. In a few days a discharge appears. This is watery at first, but may become catarrhal, heavy, mucous-like and turbid. In severe cases it resembles pus. The lining membrane of the eyelids appears red and tears may flow from the eye. Sometimes the animal acts dull and feverish, but this symptom does not last longer than one or two days unless complicated by sore throat.
Inflammation of the throatis a common complication of "colds." It is characterized by difficulty in swallowing and partial, or complete loss of appetite. Drinking or exercising causes the animal to cough. If the larynx as well as the pharynx is inflamed, distressed and noisy breathing may occur. Pressure over the region of the throat causes the animal pain.
Common "cold" terminates favorably within a week. Chronic catarrh may persist until the cause is removed and the necessary local treatment applied. Inflammation of the pharynx and larynx may persist for several weeks unless properly treated. Abscesses may form in the region of the throat. Horses frequently become thick winded as a result of severe attacks of sore throat.
The treatmentis both preventive and curative. "Colds" and sore throat can be largely prevented by good care, exercise and properly ventilated stables. Mild cases require a light diet, comfortable quarters and a dry bed. Allowing the animal to inhale steam three or four times daily is useful in relieving the inflammation. Easily digested feeds, and in case the animal has difficulty in swallowing, soft feeds and gruels, should be given. The throat may be kept covered with a layer of antiphlogistin and bandaged. Glycoheroin may be given in from teaspoonful to tablespoonful doses, depending on the size of the animal. Chlorate of potassium may be given in the drinking water.
If the animal becomes run down in flesh, as sometimes occurs in chronic catarrh, bitter tonics should be given. In the latter disease, it is sometimes necessary to trephine and wash out the sinus or sinuses affected with an antiseptic solution. It may be necessary to continue this treatment for several weeks.
BRONCHITIS.—Inflammation of the bronchial tubes may be either acute or chronic. Acute bronchitis is especially common in the horse, while the chronic form is more often met with in the smaller animals, especially hogs. This disease is most common among horses during the changeable seasons of the years. It iscausedby warm, close stables or stalls, and irritating gases emanating from the floor, or manure in the stall. In general, the causes are about the same as in cold in the head. In young animals and hogs, the inhalation of dust, and bronchial and lung worms commonly cause it. Verminous bronchitis usually becomes chronic.
In the acute formof the disease thesymptomscome on very quickly, the fever is high and the pulse beats and respirations are rapid. Chilling of the body occurs, and the animal may appear dull and refuse to eat. The animal coughs frequently. Recovery occurs within a few days, unless complicated by sore throat and pneumonia. In the horse, bronchitis is not a serious disease, but in other animals recovery is delayed and complications are more common.
In chronic bronchitisin the horse, the animal coughs frequently, there is more or less discharge from the nostrils and the respirations may become labored when exercised. The animal is usually weak, in poor flesh and unfit for work. In other cases, symptoms of broken wind are noticed. Severe coughing spells on getting up from the bed, or on moving about are characteristic of bronchitis in hogs. Verminous bronchitis in calves and lambs is characterized by severe spells of coughing, difficult and labored breathing and a weak, emaciated condition.
The preventive treatmentis the same as for "colds." In the acute form the treatment consists largely in careful nursing. Properly ventilated, clean quarters that are free from dust should be provided. The animal should be covered with a light or heavy blanket, depending on the temperature of the stable, and the limbs bandaged. A light diet should be fed for a few days. It is advisable to give the animal a physic of oil. The inhalation of steam every few hours during the first few days should be practised. Glycoheroin may be given three or four times a day.
Animals affected with chronic bronchitis should not be exercised or worked. We should guard against their taking cold, give nourishing feeds, and a tonic if necessary.
CONGESTION OF THE LUNGS.—Pulmonary congestion is generally due to overexertion and exposure to extreme heat or cold. It may occur if the animal is exercised when sick or exhausted. Hogs that are heated from exercise and allowed access to cold water, may suffer from a congestion or engorgement of the lungs. It may be present at the beginning of an attack of pneumonia or pleurisy.
The symptomsare difficult breathing and the animal fights for its breath. The body temperature may be several degrees above the normal. In the mild form, the above symptoms are not so marked. The onset and course of the disease are rapid, recovery, pneumonia, or death often occurring within twenty-four hours.
Pulmonary haemorrhageis not uncommon. The discharge from the nostrils may be slightly tinged with blood, or there may be an intermittent discharge of blood from the nostrils or mouth. The mucous membranes are pale, the animal trembles and shows marked dyspnoea.
The preventive treatmentconsists in using the proper judgment in caring for, and in working or exercising animals. This is especially true if the animal is affected with acute or chronic disease. At the very beginning, bleeding should be practised. Hot blankets renewed frequently and bandages to the limbs is a very necessary part of the treatment. In case of severe pulmonary haemorrhage, treatment is of little use.
PNEUMONIA.—Inflammation of the lungs is more common in horses than in any of the other domestic animals. The croupous form is the most common. The inflammation may affect one or both lungs, one or more lobes, or scattered lobules of lung tissue. The inflammation may be acute, subacute or chronic.
The causesare very much the same as in other respiratory diseases. Exposure to cold and wet, stable draughts, becoming chilled after perspiring freely and washing the animal with cold water are the common causes of pneumonia. Inflammation of the lungs is especially apt to occur if the animal is not accustomed to such exposure. Animals affected with other respiratory diseases are predisposed to pneumonia. Drenching animals by way of the nostril and irritating drenches, or regurgitated feed passing into the air passages and lungs are the traumatic causes of pneumonia.
The symptomsvary in the different forms of pneumonia. In case pneumonia occurs secondarily, the earliest symptoms are confounded with those of the primary disease. The first symptoms noticed may be a high body temperature, as indicated by chills, and refusing to eat. The visible mucous membranes are red and congested, the nostrils dilated, the respirations quickened and difficult, the expired air hot and the pulse beats accelerated. The animal coughs, and in the horse, a rusty discharge may be noticed adhering to the margins of the nostrils. The horse refuses to lie down if both lungs are inflamed. In severe cases the expression of the face indicates pain, the respirations are labored, the general symptoms aggravated, and the animal stands with the front feet spread apart. Cattle are inclined to lie down, unless the lungs are seriously affected. Hogs like to burrow under the litter.
The course of croupous pneumoniais typical, and unless it terminates fatally in the first stage, the periods of congestion, hepatization and resolution follow each other in regular manner. Auscultation of the lungs is of great value in diagnosing and watching the progress of the disease. It is more difficult to determine the character of the lung sounds in the horse and cow than it is in the small animals. This is especially difficult if the animal is fat. During the period ofcongestionwhich lasts about a day, one can hear both healthy and crepitating sounds. The period ofhepatizationis characterized by an absence of sound over the diseased area. The inflammatory exudates become organized at the beginning of this stage, and the air can not enter the air cells. This period lasts several days.Resolutionmarks the beginning of recovery or convalescence. Toward the end of the second period, the inflammatory exudate in the air cells has begun to degenerate. In the last stage, these exudates undergo liquefaction and are absorbed, or expelled by coughing, in from seven days to two weeks, depending on the extent of the inflammation and the general condition of the animal.
In the subacute formthe symptoms are mild and may subside within a week. Sometimesabscessesform in the lung.Gangrenous inflammationof the lung can be recognized by the odor of the expired air and the severity of the symptoms. This form of pneumonia terminates fatally. If the larger portion of the lung tissue is inflamed, death from asphyxia may occur in the second stage.
The success in thetreatmentof pneumonia depends largely on the care. Properly ventilated, clean, comfortable quarters and careful nursing are highly important. Large animals should be given a roomy box stall. Cold does not aggravate pneumonia, providing the animal's body is well protected with blankets and the limbs bandaged. Wet, damp quarters and draughts are injurious. Hogs should be given plenty of bedding to burrow in. A light, easily digested diet should be fed. Very little roughage should be fed. If the animal does not eat well, it may be given eggs and milk. Weak pulse beats should be treated by giving digitalis and strychnine. Counterirritation to the chest wall is indicated. During convalescence, bitter tonics may be given. Constipation should be treated by giving the animal castor or linseed oil.
PLEURISY.—Inflammation of the pleura is most common in horses. It occurs in all farm animals and is frequently unilateral. There are two forms of pleurisy, acute and chronic. Pleuropneumonia is common when the cause is a specific germ. This occurs in tuberculosis, pleuropneumonia of horses and pneumococcus infection.
The common causesare exposure to cold, chilling winds, draughty, damp quarters, and drinking cold water when perspiring. Injuries to the costal pleura by fractured ribs and punctured wounds may cause it to become inflamed.
The early symptoms of acute pleurisy are chills, rise in body temperature, pain and abdominal breathing. The most characteristic symptom is the ridge extending along the lower extremities of the ribs (pleuritic ridge). The animal does not stand still as in pneumonia, but changes its position occasionally, its movements in many cases being accompanied by a grunt. Pressure on the wall of the chest causes the animal to flinch and show evidence of severe pain. Large animals rarely lie down. The cough is short and painful. On placing the ear against the wall of the chest and listening to the respirations, we are able to hear friction sounds. After a few days effusion occurs in the pleural cavity. Although the animal may have refused to eat up to this time, it now appears greatly relieved and may offer to eat its feed. This relief may be only temporary. If the fluid exudate forms in sufficient quantity to cause pressure on the heart and lungs and interfere with their movement, the pulse beat is weak, the respirations quick and labored, the elbows are turned out and the feet are spread apart. All of the respiratory muscles may be used. The expression of the face may indicate threatened asphyxia. We may determine the extent of the pleural exudate by auscultation. There is no evidence of respiratory sounds in that portion of the chest below the surface of the fluid. Dropsical swellings may occur on the under surface of the breast and abdomen.
In subacute casesevidence of recovery is noted in from four to ten days.Acute pleurisyvery often terminates fatally. Under the most favorable conditions, recovery takes place very slowly, sometimes extending over a period of several months. It is not uncommon for the horse to continue having "defective wind."
The treatmentconsists in good care, well ventilated quarters and careful nursing, the same as recommended in the treatment of pneumonia. At the very beginning, the pain may be relieved by the administration of small doses of morphine. If the conditions in the stable permit, a hot blanket that has been dipped in hot water and wrung out as dry as possible, may be applied to the chest wall and covered with a rubber blanket. This treatment should be continued during the first few days of the inflammation. These applications may be reinforced by occasionally applying mustard paste to the sides of the chest.
The animal should be allowed to drink but a limited amount of water. The feed must be highly nutritious. Milk and eggs should be given if necessary. A laxative dose of oil should be given. Calomel, aloes, and digitalis are recommended when the effusion period approaches in order to increase the elimination of fluid, and lessen its entrance into the body cavity. If the amount of effusion is large, puncture of the thoracic cavity with a trocar and cannula may be practised. This operation should be performed carefully, and all possible precautions used against infection of the wound. During the later period of the disease iodide of potassium, iron and bitter tonics should be given.
BROKEN-WIND, HEAVES.—The terms broken-wind and heaves are used in a way to include a number of different diseases of the respiratory organs of the horse. The term heaves is applied almost wholly to an emphysematous condition of the lungs. Broken-wind may include the following diseased conditions: obstruction of the nasal passages by bony enlargements and tumors; tumors in the pharynx; enlarged neck glands; collection of pus in the guttural pouches and paralysis of the left, or both recurrent nerves (roaring).
The common causesof heaves are pre-existing diseases of the respiratory organs, severe exercise when the animal is not in condition and wrong methods of feeding. Heaves is more common in horses that are fed heavily on dusty timothy and clover hay and allowed to drink large quantities of water after feeding, than in horses that are fed green feeds, graze on pastures or receive prairie hay for roughage. Chronic indigestion seems to aggravate the disease. Over-distention of the stomach and intestines due to feeding too much roughage and grain interferes with respiration. Severe exercise when in this condition may result in over-distention, dilation and rupture of the air cells. This is the most common structural change met with in the lungs of horses affected with heaves. It is termed emphysema.
The common symptomsnoted are the double contraction of the muscles of the flank with each expiration, a short, dry cough and the dilated nostrils. The frequent passage of gas is a prominent symptom in well-established cases of heaves. Chronic indigestion is commonly present in heavy horses that are not well cared for, or are given hard work. This condition aggravates the distressed breathing.
Heaves is a permanent disorder, but it may be relieved by climatic changes and careful attention to the animal's diet.
The followingpreventive treatmentis recommended: Dusty hay should not be fed to horses. Clover hay is not a safe feed for horses that are worked hard. When starting on a drive after feeding, the horse should not be driven fast, but allowed to go slowly for a few miles.
The symptoms can be greatly relieved by careful attention to the diet. A limited quantity of roughage should be fed, and this should be good in quality and fed in the evening. During the warm weather, the animal should be watered frequently. After quitting work in the evening the animal may be allowed to drink as much water as it wants. Plenty of grain, soft feed and roots may be fed. A small handful of flaxseed meal given with the feed helps in keeping down constipation. Fowler's solution of arsenic may be given twice daily with the feed, in half-ounce doses for a period of ten days or two weeks. Chronic indigestion should be combated by digestive tonics.
1. Name the organs that form the anterior and posterior air passages.
2. To what conditions are the injurious effects of keeping animals in apoorly ventilated stable due?
3. State the purpose of ventilation. How can the need of ventilation bedetermined in a stable?
4. State the causes of "cold" in the head; give the treatment.
5. State the cause of bronchitis; give the treatment.
6. What are the causes of pneumonia? Describe the symptoms and treatment.
7. What symptoms are characteristic of pleurisy? Give the treatment for pleurisy.
8. Give the causes and treatment of "heaves."
GENERAL DISCUSSION.—The circulatory organs are the heart, arteries, veins and lymphatics. Theheartis the central organ of the circulatory system (Fig. 23). Its function is to force the blood through the blood-vessels. It is situated in the thoracic cavity between the lungs, and enclosed by a special fold of the pleura, the pericardial sack. There are two kinds of blood-vessels, arteries and veins. Thearteriesleave the heart and carry the blood to the many different organs of the body. Theveinsreturn to the heart and carry the blood from the body tissues. Thecapillariesare small blood-vessels, microscopic in size, that connect the arteries with the veins. The arteries carry the pure blood. The opposite is true, however, of the lesser or pulmonary system. The pulmonary artery carries the impure blood to the lungs, and the pulmonary veins carry the pure blood back from the lungs. Thelymphatic vesselscarry a transparent or slightly colored fluid and chyle from the tissues and alimentary canal. This system of vessels empties into the venous system.
[Illustration: FIG. 23.—Photograph of model of horse's heart: auricle; ventricle; pulmonary artery; pulmonary veins; posterior aorta; and anterior aorta.]
The functions of the bloodare to nourish the body tissues; furnish material for the purpose of the body secretions; supply the cells of the body with oxygen; convey from the tissues injurious substances produced by the cellular activity; and destroy organisms that may have entered the body tissues. The cellular and fluid portions of the blood are not always destructive to disease-producing organisms. In certain infectious diseases, the fluid portion of the blood may contain innumerable organisms, and destruction of the blood cells occurs.
In inflammationof tissue the circulation of the blood in the inflamed part undergoes certain characteristic changes. At the beginning there is an increase in the blood going to the part. This is followed by a slowing of the blood stream in the small vessels, and the collecting of the blood cells in the capillaries and veins. These circulatory changes are followed by the migration of the blood cells, and the escape of the fluid portion of the blood into the surrounding tissue. The character of the above circulatory changes depends on the extent of the injury to the tissue.
PALPITATION.—This disturbance in domestic animals seems to be purely functional. It may occur independent of any organic heart disease. A highly nervous condition, excitement, over-exertion, debility from disease and the feeding of an improper ration are the common causes.
The heart beats are so violent and tumultuous as to shake the body, and be noticed when standing near the animal. The heart sounds are louder than normal and the pulse beats small and irregular. It may be differentiated from spasm of the diaphragm by determining the relationship of the heart beats to the abrupt shocks observed in the costal and flank regions.
The treatmentconsists in keeping the animal quiet and avoiding any excitement. A quiet stall away from the other animals is best. The treatment of palpitation resulting from some organic heart disease must be directed largely at the original disease. Morphine is commonly used for the treatment of this disorder. Weak, anaemic animals should receive blood and bitter tonics. If we have reason to believe that the disturbance is caused by improper feeding, the animal should receive a spare diet for a few days. In such cases it is advisable to administer a physic.
PERICARDITIS.—Inflammation of the pericardial sack is usually a secondary disease. It is frequently met with in influenza, contagious pleuropneumonia, hog-cholera and rheumatism. Cattle may suffer from traumatic pericarditis caused by sharp, pointed, foreign bodies passing through the wall of the reticulum and penetrating the pericardial sack. The jagged ends of fractured ribs may cause extensive injury to neighboring parts, and the inflammation spreads to the pericardial sack.
The symptomsof pericarditis may not be recognized at the very beginning when the disease occurs as a complication of influenza, or infectious pleuropneumonia. The manifestation of pain by moving about in the stall, refusing to eat and the anxious expression of the face are the first symptoms that the attendant may notice. The body temperature is higher than normal, and the pulse rapid and irregular. On auscultation, friction sounds that correspond to the tumultuous beats of the heart are heard. When fluid collects within the pericardial sack, the heart beats become feeble and the pulse weak. Labored breathing and bluish discoloration of the lips follow. The disease usually runs a very acute course. The prognosis is unfavorable.
The treatmentrecommended in pneumonia is indicated in this disease. Absolute rest and the feeding of an easily digested, laxative diet is a very essential part of the treatment. At the very beginning morphine may be given to quiet the tumultuous beats of the heart. Cold applications to the chest wall in the form of ice packs should be used. Heart tonics and stimulants such as digitalis, strychnine and alcohol should be administered when the pulse beats weaken. To promote absorption of the exudate, iodide of sodium may be given. Mustard paste, or a cantharides blister applied over the region of the heart is useful in easing the pain and overcoming the inflammation. If fluid collects in sufficient quantity to seriously interfere with the heart action, the sack may be punctured with the trocar and cannula and the fluid withdrawn. Great care must be used to avoid injury to the heart and infection of the part.
[Illustration: FIG. 24.—Elephantiasis in horse.]
ACUTE LYMPHANGITIS.—This is an inflammation of the lymphatic vessels of one or both hind limbs. The attack comes on suddenly and usually occurs in connection with rest, and in horses that are of slow, quiet temperament. Theexciting causeis an infection of the part with bacteria, the infection probably occurring through some abrasion or small wound in the skin.
The local symptomsare swelling, tenderness and lameness in the affected limb. The animal may refuse to support its weight on the affected limb. The lymphatic glands in the region are swollen, and the swelling of the limb pits on pressure. In the chronic form of the disease, the regions of the cannon and foot remain permanently enlarged, and the swelling is more firm than it is in the acute form (Fig. 24).
The general symptomsare high body temperature, rapid pulse and the partial or complete loss of appetite.
The following treatmentis recommended: Exercise is indicated in cases that are not sufficiently advanced to cause severe lameness, or inability to use the limb; rest and the application of woollen bandages wrung out of a hot water solution of liquor cresolis compound are recommended; Epsom salts in one-half pound doses may be given and repeated in two or three days; a very light diet of soft feed should be given; liniments shouldnotbe applied until the soreness in the limb has subsided; iodide of potassium may be given twice daily with the feed.
1. What are the functions of the blood and lymph?
2. State the changes occurring in the circulation in inflamed tissue.
3. What is palpitation? Give the causes and treatment.
4. What are the common causes of pericarditis?
5. Give the causes and treatment of acute lymphangitis.
GENERAL DISCUSSION.—The nervous system may be divided into central and peripheral portions. Thecentral portioncomprises the brain or encephalon and the spinal cord. These organs are lodged in the cranial cavity and spinal canal. The nerves and ganglia comprise theperipheral portion. The nerves form white cords that are made up of nerve fibres. The ganglia are grayish enlargements formed by nerve cells and supporting tissue, situated at the origin of the nerve trunk or along its course.
The brainis an oval mass of nerve tissue elongated from before to behind, and slightly depressed from above to below. It terminates posteriorly in the spinal cord. It is divided into three portions:cerebrum, isthmusandcerebellum(Fig. 25).
The cerebrumforms the anterior portion. It is divided into two lateral lobes or hemispheres by a deep longitudinal fissure. The surface of the cerebral hemispheres is gray and roughened by pleats or folds separated by grooves or fissures. The gray or cortical layer is distinct from the white or connecting structure. The cortical layer is made up of nerve cells or areas which control the voluntary muscles of the body. It is connected with the special senses of touch, temperature and muscle-sense. The gray layer is connected with the posterior portion of the brain, the isthmus or medulla oblongata, by the white nerve tissue.
The isthmusormedulla oblongatais elongated from before to behind and connects the cerebral hemispheres with the spinal cord, anteriorly and posteriorly. It is divided into several different portions, and is made up largely of white connecting fibres with nuclei of gray matter scattered through them. The isthmus is hollowed out by a system of small ventricles that extend from the cerebral hemispheres to the spinal cord, where they terminate in a small, central canal. The isthmus is the highway between the spinal cord and the higher nerve centres. It has in it certain cell centres that give origin to six of the cranial nerves.
[Illustration: FIG. 25.—Photograph of model of horse's brain: longitudinal section; lateral view; cerebrum; cerebellum; and isthmus.]
The third division of the brain is thecerebellum. This is a single mass supported by the isthmus. It is situated posterior to the cerebrum, from which it is separated by a transverse fold of the membranes covering the brain. This mass of nerve tissue is much smaller than the cerebrum. The white nerve tissue forms central nuclei which send out branches that ramify in every direction. The centre of the muscular sense is said to be located in this division of the brain. A second function is the maintenance of body equilibrium through its connection with the nerve of the middle ear.
The spinal cordcommences at the posterior opening (occipital foramen) of the cranial cavity, and terminates posteriorly in the lumbar region at the upper third of that portion of the spinal canal belonging to the sacrum. It is thick, white in color, irregularly cylindrical in shape, slightly flattened above and below and reaches its largest diameter in the lower cervical and lumbar regions. The spinal canal is lined by the outer membrane that envelops the cord, which aids in fixing this organ to the wall of the canal. The spinal cord is formed by white and gray nerve tissue. The gray tissue is situated within the white, and it is arranged in the form of two lateral comma-shaped columns connected by a narrow commissure of gray matter. The extremities of the lateral gray columns mark the origin of the superior and inferior roots of the spinal nerves. The white tissue of the cord is also divided into lateral portions by superior and median fissures. The inferior fissure does not extend as far as the gray commissure, leaving the lateral inferior columns connected by a white commissure. There are certain centres in the spinal cord that are capable of carrying on certain reflex actions independent of the chief centre in the brain. The white matter of the cord is made up of paths over which impulses to and from the brain are transmitted.
There are twelve pairs of cranial nerves. Two pairs belong exclusively to the special senses, smell and sight. Altogether there are ten pairs that are devoted to functions connected with the head, either as nerves of the special senses or in a motor or sensory capacity (Figs. 26 and 27). There are two pairs distributed to other regions. These are the tenth and eleventh pairs. The tenth pair or pneumogastric is distributed to the vital organs lodged within the body cavities.
There are forty-two or forty-three pairs of spinal nerves given off from the spinal cord. The spinal nerves have two roots, superior and inferior. The superior is the sensory root and the inferior is the motor root, both uniting to form a mixed nerve trunk. The sensory root possesses a ganglion from which it originates.
Generally speaking, the cerebrospinal system deals with the special senses, movement of skeletal or voluntary muscles and cutaneous and muscular sensations. In addition to the above there is a distinct system termed the sympathetic. Thesympathetic systemconsists of a long cord, studded with ganglia, extending from the base of the neck to the sacrum. The ganglia are connected with the inferior roots of the spinal nerves. This cord is connected with groups of ganglia and nerve fibres in the abdominal region, and this in turn is connected with terminal ganglia in distant tissues. This system of nerves is distributed to the vital organs of the body.
[Illustration: FIG. 26.—Unilateral facial paralysis caused by injury to seventh cranial nerve; note position of lip.]
[Illustration: FIG. 27.—Bilateral facial paralysis. This colt was affected with facial paralysis when born.]
CONGESTION AND ANAEMIA OF THE BRAIN.—In congestion of the brain, the blood-vessels distributed to the nerve tissue become engorged with blood. It may be either active or passive.
The cause of anaemiaof the brain is an insufficient blood supply. This may be due to an abundant haemorrhage and cardiac weakness caused by shock or organic heart disease.
The causes of congestionof the brain are faulty methods of care and feeding. It sometimes occurs when horses are shipped in poorly ventilated cars, or kept in close stables. Climatic changes, or changing the stable and feed, may cause it. Extremely fat animals and animals that are rapidly putting on fat are predisposed to this disorder. Improper methods of feeding, lack of exercise, constipation and excitement are the most common causes. Passive congestion may result from pressure on the jugular vein by obstructing the flow of blood from the brain, and raising blood pressure in the blood-vessels of the brain. It is sometimes caused by organic heart trouble.
The symptomscome on very suddenly in congestion of the brain. The disease may manifest itself as soon as the animal is moved out of the stall or bed, or it may come on while it is feeding. In slight cases, the animal appears excited and restless, the eyes are bright, the pupils are dilated, and the pulse beats and respirations quickened. If the animal is moving about, it may stop suddenly and show marked symptoms of a nervous disorder, such as turning around, running straight ahead and falling down. The period of excitement is usually brief and may be followed by marked depression. The mucous membranes of the head are a deep, red color.
The symptomsin anaemic conditions of the brain are loss of consciousness, stumbling, falling to the ground and sometimes convulsions. The pig and dog may vomit. Favorable cases return to the normal within a few hours. Acute inflammatory diseases of the brain and its coverings are associated with cerebral hyperaemia or congestion.
The treatmentof mild cases is to give the animal quiet, well-ventilated quarters, where it can not injure itself. The animal should be first subjected to a severe diet and later given easily-digested feed. If it appears greatly excited, bleeding should be practised. Cold applications to the head should be used in all cases in the small animals. For internal treatment, purgatives are indicated. In cases of anaemia, stimulants, vigorous massage, artificial respiration and injection of physiological salt solution are indicated.
SUNSTROKE AND HEATSTROKE.—Most writers make no distinction between heatstroke and sunstroke. The latter is caused by the direct rays of the sun falling on the animal, and the former from a high temperature and poor circulation of air in the surroundings. Under such conditions, the physical condition of the animal and exertion play an important part in the production of the nervous disturbance.
The first symptomsusually noted are rapid, labored breathing, depression and an anxious expression on the face. The horse usually stops sweating. The body temperature is extremely high, the pulse beats weak, the animal trembles, falls to the ground and dies in a convulsion. Unless measures directed toward relief of the animal are taken early in the attack, death commonly occurs. Overheating is rather common in horses that are worked hard during the extremely warm weather. Horses that have been once overheated are afterwards unable to stand severe work during the hot months of the year. Horses in this condition become unthrifty, do not sweat freely and pant if the work is hard and the weather is warm.
The preventive measuresconsist in not exposing animals that are fat, or out of condition to severe exercise if the day is close and hot, especially if they are not accustomed to it. When handling or working animals during hot weather all possible precautions to prevent overheating should be practised.
The treatmentconsists in placing the animal in a cool, shady place and fomenting the body with cold water. The cold packs or cold fomentations should be applied to the head and forepart of the body only. Small doses of stimulants may be given.
MENINGO-CEREBRITIS.—The discussion of inflammation of the brain and its coverings can be combined conveniently, as the causes, symptoms and treatment vary but little. This disorder is met with in all species of domestic animals, but it is most common in horses and mules. Some writers state that meningo-cerebritis is more common during the warm season than it is in the winter. However, this does not hold true in all sections. In the middle west, this disease is more common in late fall and winter.
It is commonly causedby taking into the body with the feed and water certain organisms and toxins that are capable of producing an inflammation of the brain. The infectious organism or toxins are taken up by the absorbing vessels of the intestines.
The secondary form of the disease usually occurs in connection with other diseases such as influenza, tuberculosis and acute pharyngitis, or as a result of wound infection. Unhygienic conditions, as unsanitary and poorly ventilated stables and filthy drinking places, play a very important part in the production of the simple or acute form of meningitis.
Sudden changes in the feed and the feeding of rotten, mouldy feeds may cause it. In the fall and winter it may follow the feeding of too heavy a ration of shredded fodder or any other dry feed. Other exciting causes are overexertion, changes in climate, excitement, injuries to the head and the feeding of too heavy and concentrated a ration.
The symptomsvary in the different individuals, but in general they are the same. At first the animal is dull, or extremely nervous and sensitive to sounds. The pupils of the eye are unevenly contracted at first, later dilated. The eyes may appear staring, or they are rolled about, so that the white portion is prominent. The unusual excitement is manifested in different ways by the different species. During the dull period the animal is indifferent to its surroundings. When it is excited, the pulse beats and respirations are accelerated. The body temperature is often elevated early in the disease. There is a partial or complete loss of appetite. Paralysis may be the most prominent symptom. The animal lies in a natural position, or stretched out and lifting the head occasionally and moving the limbs, but it is unable to rise. Loss of sensibility may gradually progress until the animal becomes semiconscious, or comatose.
In case the inflammation is acute and involves the greater portion of the brain and its coverings, death occurs within a few days. Occasionally the animal survives several weeks. There are few permanent or complete recoveries.
The principal lines of treatmentare preventive measures and careful nursing. This is one of the diseases that can be largely prevented by observing all possible sanitary precautions in caring for animals. It is admitted by writers that the greater majority of cases of inflammation of the brain and its coverings are caused by infection. Proper stable construction, ventilation and disposal of the manure, an occasional disinfection of the stable, cleaning and disinfecting the drinking places and water tanks, and the necessary attention to the ration greatly reduce the loss from this disease.
The animal should be gotten into a dark, quiet, roomy stall that is well bedded. A swing may be placed under a large animal if it is able to support any of its weight, and there is no evidence of nervous excitement. We should do nothing to disturb it. If possible, the position of the animal that is unable to get up should be changed, and the bed kept clean and dry. Cold in the form of wet or ice packs should be applied to the head during the acute stage. Symptoms of excitement must be overcome by large doses of sedatives. Iodide of potassium and strychnine may help in overcoming the paralysis. The bowels should be emptied by giving an occasional physic. A very light, easily digested diet should be fed.
PARTIAL OR COMPLETE PARALYSIS OF THE POSTERIOR PORTION OF THE BODY.—This disorder is especially common in the small animals. The hog is most frequently affected.
The following causesmay be mentioned: Inflammation of the spinal cord commonly occurs in influenza, strangles and mixed infections; constipation brought on by improper feeding and insufficient exercise is a predisposing cause; injuries such as strains and blows in the region of the back may also cause it; compression of the spinal cord by the vertebrae is no doubt a very common cause; dislocation, enlargement of the disks between the vertebrae, bony enlargements resulting from strains and injuries, rickets, tuberculosis and actinomycosis and tumors commonly cause compression of the cord. It is rarely caused by parasites. Young, fat animals are especially prone to injuries in the region of the back. Such animals may suffer from malnutrition of the bones, and complete fractures of the thigh bones may occur. Extreme heat from the sun's rays and close, hot quarters are probable causes.
The symptomthat is most prominent is the partial or complete loss of control over the movements of the hind parts. The appetite may be little interfered with. The animal may sit on the haunches, with the limbs projecting forward, or swing the hind quarters from side to side in walking or trotting. Irregularity in the animal's movements is especially noticeable when turning or backing. In case the animal suffers pain, the spine is held rigid or arched, and when forced to move, marked evidence of pain occurs. There may be a decrease or increase in the sensibility of the part. The increase in sensibility is noticed on striking the muscles with the hand or rubbing the hair the wrong way. Spasmodic twitching or contractions in the muscles sometimes occur. There is frequent elevation of temperature. The animal is unable to pass urine or faeces, or there may be an involuntary passage of the body excretions.
The outcome of this disease is unfavorable. Acute inflammation of the covering of the cord may subside within a few days. Cases that do not recover within a few weeks should be destroyed. Paralysis of the hind parts should not be confused with rheumatism, azoturia and other disorders that may interfere with the movements of the posterior portion of the body.
The treatmentis largely along preventive lines. A predisposition toward rickets, and injuries, may be prevented by feeding a proper ration, and permitting the animal to take exercise. The quarters and the attendant are frequently responsible for injuries. If this is the case, the rough handling of the animals should be immediately corrected, and any condition of the quarters that favors the crowding or piling up of animals should be changed. Large animals may be placed in swings if they are able to support a part of their weight on the hind limbs. This is especially indicated at the very beginning of the disorder. Small animals should be given a good bed. A very light, easily digested ration should be fed. An occasional physic should be administered. Strychnine and iodide of potassium may be given. Cold applications to the back are indicated.
1. What organs comprise the central portion of the nervous system? Peripheral portion?
2. Give a general description of the brain.
3. Give a general description of the spinal cord.
4. What is the sympathetic system?
5. Describe the causes and symptoms of congestion of the brain.
6. What is heatstroke? Give the treatment.
7. Give the preventive and curative treatment of inflammation of the brain.
8. State the causes, and give the proper treatment of paralysis of the posterior portion of the body.