Part 35

PIG. PNEUMONIA.

Symptoms, chill, burrowing, hot skin, cough, disturbed breathing, indications of exudation. Treatment, laxative, sedative, nauseant, febrifuge, wet jacket, blister.

Hogs are not exempt from this disease. They show the same symptoms of chill with hiding under the litter, followed by a hot stage, cough, hurried breathing, and (if the clothing of fat is not too thick) conclusive results on auscultation and percussion.

As treatment bleeding from the ears and tail is sometimes resorted to with questionable benefit. A laxative of three ounces of castor oil or three or four croton beans given in the food is of value. Tartar emetic in doses of ¼ grain and nitrate of potash in 10 grain doses should be shaken on the tongue at least four times daily to keep up a continued nausea and action on the urinary organs. The tartar emetic so worthless in the larger animals is of value in the pig and dog. A damp compress or blister may be used. The skin of the animal is difficult to blister, but by the use of the Danish croton liniment, mentioned for the ox, of hot water, or of a mixture of oil of turpentine and croton, 8 parts of the former and 1 part of the latter, a sufficient effect can usually be obtained.

DOG. PNEUMONIA.

Breeds most liable. Causes, over-exertion, cold baths, clipping, exposure in cold, distemper. Symptoms, chill, fever, disturbed breathing, cold extremities, cough. Treatment, dietary, nursing, laxative, nauseant, febrifuge, moist jacket, mustard, stimulants, tonics, heart tonics and careful nutrition during convalescence.

This is a frequent affection in hounds. In hunting or coursing dogs the causes are like those operating in the horse. The clipping of long haired dogs in inclement weather, swimming dogs in winter without afterwards drying or heating them by exercise, and shutting them out of doors at night, when accustomed to a warm dwelling are occasional causes. It sometimes occurs epizootically and frequently supervenes during distemper.

The chief symptoms of chill, fever, and difficulty in breathing are like as in other animals, while the results of auscultation and percussion are more satisfactory than in any other domestic animal. The dog sits on its haunches to facilitate breathing; his elbows turned out, his mouth open and his tongue protruded. Coldness of the ears and a short quick cough are usually marked symptoms.

Treatment. The general care applicable to other animals is equally demanded here. The diet should consist of mild broths, or farinaceous foods with a little gravy if necessary to render it palatable.

Bleeding from the jugular has been recommended and may be admissible at the outset of the disease in a very few appropriate cases. If costiveness exists a tablespoonful of castor oil may be given (more or less according to the size of the animal), following this up by the tartar emetic, nitre and sugar recommended for bronchitis. The poultice jacket is of great value. Mustard poultices may later be applied to the sides of the chest. Stimulants, tonics and nourishing diet may be required during convalescence, or when the disease assumes a low type.

CROUPOUS PNEUMONIA IN FOWLS.

In chickens exposure and neglect are alleged causes. Foul coops and the contrast between the warm building and cold outer air are justly blamed. Ruffled feathers, drooping head, dark colored comb and wattles, trailing wings, a disposition to gape, panting and cough are noticed. Under the wings and over the back crepitations and dulness may be detected. The patient may take a teaspoonful of castor oil, and saltpetre or iodide of potassium may be given in the drinking water. In careful doses the other remedial measures may be attempted.

Pneumonia in birds. Causes, exposure, neglect, foul coops, hot, close houses, etc. Symptoms, erect plumage, drooping head, wings, and tail, dark comb, gaping, panting, cough, crepitation. Treatment, hygienic, laxative, febrifuge.

ACUTE PLEURISY IN THE HORSE. PLEURITIS.

Causes, cold, damp, soils and exposures, as with rheumatism, youth, vigor, heavy diet, digestion, or hepatic disorder, over-exertion, perspiration and succeeding chill, wading or swimming rivers, standing in snow, salted snow, rain, sleet, snow, draughts between open doors and windows, clipping, cold sponging of legs, tuberculosis, a common cause in man and cattle is rare in horses, surface pneumonias, cancers, actinomycosis, tumors. Traumas from broken rib, penetrating intercostal wound, blows, contusions, ruptured pulmonary or intercostal abscess. Irritant (infectious) exudate suggests microbes. Symptoms, chill, reaction, partial sweats, pawing, pointing one foot, hyperthermia, hard, jarring pulse, hurried breathing, inspiration catching, pleuritic ridge, uneasy movements, hacking cough, tumors and twitching of chest muscles, tender intercostals, grunting, friction sound, subsiding with appearance of dull area below, signs of effusion, relief, dyspnœa, lifting flanks and loins, perspirations, stocking limbs, pasty swelling on sternum, effusion of same level on both sides, creaking sounds, splashing, gurgling, metallic tinkling, weakness, sinking. Signs of adhesions, compression of lung, abscess. Duration. Lesions, early formation of false membranes, pleuritic effusion, its composition, its color at different stages, dry pleurisy, sero-fibrinous, sero-fibro-purulent, hydro-pneumothorax, tubercle. Prognosis. Treatment, during the chill, warm air, clothing, drinks, injections, compresses, pilocarpin during early inflammatory stage, derivatives, dry cupping, mustard, cantharides, hot water, or air, cold applications, laxatives, calmatives, antirheumatics, alkaline agents, with bitters, diuretics, heart tonic, iodine, mercury, thoracentesis.

Causes. Pleurisy is common in all domestic animals and especially so in cold, damp, exposed localities which suffer equally from rheumatism. It occasionally extends to the fascia of the limbs, the joints, or the navicular or other trochlea as a rheumatic affection. The disease is prevalent among young and vigorous horses, four or five years old, on stimulating feeding. Here hepatic derangements and poisons, over-exertion, perspiration and succeeding chills are especially to be suspected. Plunging the limbs in ice cold water as in wading a river (Fromage), standing in snow and above all in salted snow, or facing a cold rain, sleet, or snow when perspiring or fatigued, are recognized causes. A full drink of ice cold water when freely perspiring, and followed by standing in the frosty air, or in a cold current indoors. Exposure unblanketed after clipping in winter (Field, Trasbot), and even sponging the body or legs with cold water when heated or fatigued or both. St. Cyr found that pneumonias stood to pleurisies as 3: 1, Trasbot as 10: 1, yet the latter draws attention to the fact that in cavalry horses habituated to the stable and sent out into camps in the depth of winter, the pleurisies are more numerous than pneumonias. This may suffice to show the importance of the rôle filled by cold and chill in the production of pleurisy. Yet many physicians look upon the chill as a predisposition only, while the true origin of disease is microbian. And in man a large proportion of pleurisies appear to be distinctly tuberculous. Bowditch traced 90 cases of acute pleurisy and found that 32 had tuberculosis. The objection to generalizing too largely on this for the lower animals is that the horse and dog, in which tuberculosis is rare, are by far the most common subjects of pleurisy, whilst cows which are very prone to tuberculosis show few cases of simple pleurisy. Again we find pleurisy in the horse as the result of other diseases localized in or adjacent to the pleura, and where there is nothing to indicate tuberculosis. Thus it follows pneumonia approaching the surface of the lung, cancers, actinomycosis and other tumors, and traumas—a pulmonary abscess bursting into the pleura, a broken rib scratching and lacerating the lung, a perforating wound of the intercostal space, or in cattle a sharp pointed body advancing from the reticulum toward the heart.

But the presumptive absence of the tubercle bacillus in the great majority of pleurisies in the horse does not prove the absence of all pathogenic microbes. Trasbot, who rejects the microbian theory, found that the injection of a little of the exudate into the pleural cavity of a sound horse, always determined a generalized pleurisy. Injections of distilled water with the same antiseptic precautions, made separately by himself and Laborde, had no pathogenic effect. Trasbot attributes the pleurisy vaguely, to the irritant effect of the exudate, but if it should finally be shown that this exudate contains microbes, though they may not be those of tuberculosis, the irritant action will be much more clearly explained. There are forms of pleurisy which are unquestionably the result of microbes, as in lung plague, influenza, canine distemper, glanders, tuberculosis, pneumo-enteritis, actinomycosis, and theoretically it might be supposed that in our ordinary acute pleurisies, other germs that have been lurking harmless in the system may take occasion by reason of the lowered vitality induced by a chill, or a trauma, to colonize the thoracic serosa and develop pleurisy. Under such a theory, the predisposing and microbian element would remain equally effectual, but only operative when conjoined, neither being pathogenic without the other.

Until the constancy of the microbian factor is demonstrated we must recognize the time honored doctrine, that pleurisy may be due to cold, exposure, over exertions, to traumatic injuries, blows, concussions, fractures, penetrating wounds, and to extension by contiguity from adjacent diseases.

Most commonly pleurisy is unilateral on the right side but is often on the left or on both sides.

Symptoms. There is the early symptom of shivering followed by a hot stage in which the limbs participate and partial sweats bedew the surface. There are first uneasy movements of the fore limbs with some lifting of the flanks and this discomfort increases until the patient is panting with pain and occasionally glancing round at his heaving flanks and even pawing as in colic. If the pleurisy is confined to one side the corresponding fore limb is often advanced before the other. The temperature is 102° and upward. The pulse is quick, hard and incompressible being usually compared to a jarred wire and beats from 48 to over 60 per minute. The breathing is highly characteristic. It is hurried, is carried on chiefly by the abdominal muscles to avoid the rubbing of the inflamed pleuræ on each other, and has the inspiration short and suddenly checked by an audible closure of the glottis while the expiration is slow and prolonged. This character of the breathing is well observed when the ear is placed against the false nostril. The laboring abdominal muscles stand out as a ridge from the outer angle of the ilium along the lower ends of the last ribs (pleuritic ridge). A tremor on this line is often noticeable in the early stages. It may also be felt by the hand laid on the costal region. The horse does not stand obstinately still as in pneumonia, but frequently moves as if seeking an easier posture. The short, hacking cough contrasts with the deep, rare cough of pneumonia. The expired air is not so hot, nor the mucous membrane of the nose so red as in the last named disease and there is no nasal discharge. A twitching of the muscles of the chest is sometimes seen and if the intercostal muscles are pressed upon, the animal winces and frequently grunts. This last symptom is likewise seen in rheumatic disease of the intercostal muscles (pleurodynia) but the absence of the fever, the cough, and other chest symptoms sufficiently distinguish this. Auscultation detects in the early stages in addition to a healthy respiratory murmur, a friction sound audible in inspiration only in short jerks near the close of the act and comparable to the rubbing of the palm of one hand over the other laid over the ear, but this is no longer heard when effusion of liquid has taken place into the pleuræ. Percussion in the early stages detects no change from the healthy chest resonance.

If not relieved in from twenty-four to thirty-six hours, a remarkable modification of the symptoms takes place indicating the occurrence of effusion. The violent symptoms are suddenly relieved. The quick catching breathing which is in many cases accompanied by a grunt, becomes easy and though fuller than natural is comparatively regular. In particular the inspiration is free and full and comparatively painless, the sudden check and the grunt by which it was arrested having alike disappeared. The tension of the abdominal muscles and the tucked up appearance of the flanks give way; the pulse acquires a softer character, the haggard pinched countenance is relaxed, and a general appearance of comfort and even liveliness prevades the animal. This temporary improvement is often so great that the horse will take to feeding as if he had all at once recovered.

The apparent recovery is, however, only transient. Soon the pulse becomes more frequent and loses its fulness, the breathing is more laborious and attended with a characteristic lifting of the flanks and loins, the nostrils are widely dilated, the limbs outstretched and the elbows outturned, the eyes stare and project and the countenance has a haggard appearance indicating threatened suffocation. Partial sweats may break out on the surface, due to the state of nervous excitement and general relaxation and supplementing in some degree the impaired exhalation from the lungs. Auscultation over the lower region of the chest shows a complete absence of the respiratory murmur, rising to the same level precisely at all points. Percussion elicits no resonance on the same region. If the effusion has taken place slowly or existed for some time, the dulness and absence of sound will usually indicate that the liquid rises to the same level on both sides. So thin and permeable is the posterior mediastinum in its lower part that unless thickly coated by new solid exudations, the effusion readily passes through it and rises to the same height on both sides. If gas as well as liquid is produced in the pleural sac a gurgling or splashing sound may be heard on auscultation, and occasionally, after rising or other change of position, a metallic tinkling, due to droppings from the shreds of false membranes above into the fluid below.

As the disease proceeds dropsical effusions are observed beneath the skin of the breast and abdomen, a mucous rattle is heard in the trachea, the nose, ears and limbs become cold, the pulse increases in rapidity and weakness, shows the distinct anæmic tremor or thrill, and becomes rapidly imperceptible; the horse moves unsteadily and often falls suddenly dead.

This early fatality is, however, only seen in the worst cases. In those about to terminate favorably improvement is shown usually about the fourth day. The lifting of the flanks and loins becomes moderated, the ribs move more freely, the grunt ceases, the pulse is fuller, softer and less frequent, and auscultation and percussion show a steady decrease in the effusion. Appetite meanwhile returns, the horse moves more freely, lies down for a length of time in succession, and convalescence lasts from two to three weeks.

In the less fortunate cases structural changes more or less permanent, keep up symptoms of illness for a variable length of time. Sometimes after the liquid effusion has been absorbed the lung remains attached to the side of the chest by newly formed tissue (false membrane) and while this is undergoing a drying and organizing process, it gives rise to a leathery, creaking sound heard on auscultation and easily mistaken for crepitation. Sometimes an abscess forms on the surface of the pleura or in the newly organized false membrane, and either bursts into the pleural sac (empyema) where it serves to increase and sustain the irritation, or it makes its way through the intercostal spaces and is discharged externally. In this last case its advance toward the surface is heralded by an extensive inflammatory infiltration and pasty swelling much more tender to the touch than the dropsical swelling already referred to. Another condition is that in which false membranes of considerable thickness invest a lung and, following the law of all fibrous structures in process of organization, they contract and cause a compression and partial collapse of the contained lung tissue. A flattening of the corresponding side of the chest and a muffled and almost inaudible respiratory murmur is the result of this condition. In some measure these symptoms are present during convalescence in all cases of pleurisy since the lung never expands to its full size till some time after apparent recovery, but it is only when the organ is invested with false membrane that the symptoms are very apparent.

In all such cases of prolonged pleurisy from protracted structural change there is continued illness without the violent symptoms by which the acute form of the disease is manifested. The acute suffering, the restlessness, the grunt, and even the catching breathing may be absent; the temperature may be almost reduced to the healthy standard, the pulse small and tolerably soft, the appetite considerably improved and the different secretions tolerably normal; yet the pinching of the intercostal spaces causes sharp pain, and measurement, auscultation and percussion testify to the persistence of disease. The animal is hidebound, unthrifty and unequal to any exertion. The cough is weak and painful and sometimes accompanied by a grunt.

Besides the changes connected with exudation and effusion, and organization or suppuration in the exuded products, gangrene sometimes results. A case of this kind is related by Percivall.

The duration of pleurisy may thus extend from two days in very acute cases to several weeks, or even months if we estimate it by the continuance of hydrothorax in the chronic cases.