Chapter XI: Part 11

Up to the 7th day 50 per cent. were dark red; after the 7th day only 13.3 per cent.; and after the 15th day none. Up to the 7th day 83.3 per cent. were either dark red or sero-sanguineous and not one had attained to translucency. After the 7th day only 8 per cent. were of port wine hue, and by the 15th day 24 per cent. of all cases of over seven days standing were already transparent. Of all cases of over 15 days standing, 80 per cent. were perfectly translucent and none showed the dark red hue. Finally after the 30th day all remaining cases were limpid. This of course must not be applied with the same confidence in both directions. While translucency of the effusion bespeaks seven days standing and probably fifteen or twenty, the dark red hue must not be held to imply a recent date for the attack. A relapse in the course of convalescence may easily and quickly stain anew a liquid that was already limpid, or had advanced far toward this condition.

The appearance of the lung tissue in a case of confirmed pleurisy is characteristic. The lung is of a dull red color, shrunken, slightly collapsed, flabby, scarcely crepitant under pressure and heavier than water or floating in water. It is tough, not friable like hepatized lung, and its cut surface is dry, smooth, and presents the interlobular septa very well marked. This is due to the compression by effused liquid, and by the organizing and contracting false membranes covering the lung and implies nothing more than simple condensation. The air cell may be collapsed, but contains no new product and has not parted with its epithelium and the lung can be inflated through the bronchia.

_Differentiation according to the nature of the effusion._ Pathologists have divided acute pleurisy into the _dry_, _sero-fibrinous_, and _sero-fibro-purulent_.

=1. Dry or fibrinous pleurisy= has usually a more acute type and the exudate containing an excess of the fibrinogenous elements forms a coagulum or false membrane on the affected surface tending to bind that to the part adjacent—the lungs to the costal pleura. The serum, small in quantity, is in the main retained in the exudate or if set free is actively reabsorbed by the healthy pleura.

=2. Sero-fibrinous pleurisy.= This form is usually less acute and more extended involving perhaps an entire pleural sac, or even both sides of the chest. This is the common form of pleurisy and is that referred to in the experiments of St. Cyr and others above. The earliest lesions in experimental cases (with chloride of zinc solution) in dogs are an uniform bright red congestion, with a bright, shining surface as yet perfectly dry. There is already shedding of patches of the endothelial cells, swelling and proliferation of the superficial connective tissue cells and the formation of a few pus globules. This is seen in from half an hour to six hours after the application of the irritant.

Next follows the exudation of fibrine and serum, which respectively coagulate as false membrane on the inflamed membrane, or drop to the bottom of the sac as liquid. The fibrine appears as granules, little knobs and threads between and on the endothelial cells and entangling a few pus cells. The changes are now much more marked in the connective tissue cells, which are more numerous, larger, nucleated and often stellate or polygonal. Changes are well advanced in twenty-four hours. The cells go on increasing to the fourth or fifth day, when new blood vessels are formed into the membrane and may be injected from the pleura. From this time, in favorable cases absorption of the liquid proceeds, and the fibrine is organized, and by the fourteenth day is transformed into connective tissue, the superficial cells forming endothelium and the deeper, branching connective tissue cells. The result is the thickening of the pleura and the formation of adhesions. The case, however, may prove fatal, or it may be protracted through the continued production of fibrine and serum, or it may pass into empyema.

=3. Sero-fibrino-purulent pleurisy.= =Empyema.= This is usually very dangerous as well as complicated. It may supervene on the last described form. It may depend on rupture into the pleura of abscess of the lung, bronchial glands, liver, diaphragm or intercostal space and the infection of the chest cavity. It may in the same way follow the laceration of a bronchium by a broken rib, the perforation of the intercostal space by a foreign body, or (in cattle) the penetration of the chest by a sharp pointed body from the reticulum. It may follow at once on pleurisy of a very high grade. Probably in all such cases there is infection of the pleura by pus microbes. When there is a communication with a bronchium, the reticulum or the external air there are usually septic germs in addition, and the contents of the chest become fœtid.

The purulent fluid may accumulate in the lower part of the pleural sac, or it may be confined in abscess form in the false membrane, and extend thence into surrounding tissues. The pus-containing pleura, or cavity infected by the pus germs, assumes the appearance of a granulating surface, or of the lining membrane of an abscess, and continues to produce pus in greater or less amount.

The formation of pus in the pleura is known as _empyema_. When air enters the pleura through a wound perforating the chest wall, or when gas is formed in the pleura, the condition is =pneumothorax=. As liquid is usually present as well it is =hydro-pneumothorax=.

Tubercular and other forms of pleurisy have in certain cases been superadded to the specific local lesions, by which such diseases are individually characterized.

_Prognosis._ Occurring in an otherwise healthy system and especially if confined to one side of the chest, pleurisy is not frequently fatal, and under appropriate treatment recovery is oftentimes rapid and satisfactory. A certain number of cases merge into chronic hydrothorax, the inflammation apparently subsiding, but reabsorption failing to take place. The hydrothorax may last for months or even a year.

_Treatment._ If seen during the _chill_ and before inflammation has been definitely established every effort must be directed to secure its abortion, if possible. No time should be lost in placing the patient in a warm comfortable stall or box, covering him with woolen blankets and actively rubbing and loosely flannel bandaging the legs. Warm drinks and warm injections must be given. Half an ounce or an ounce of camomile or boneset in infusion in two or three quarts of hot water, or in the absence of this any of the carminatives, or etherial, alcoholic or ammoniacal stimulants may be given. Pilocarpin in 7 grain dose hypodermically may promptly secure a revulsion of blood to the skin and at once overcome the chill and prove a most effective derivative from the pleura. Placing the legs in buckets of hot water, or the whole animal in a hot air bath will often act equally well. Packing the chest and even the abdomen in a blanket wrung out of very hot water and covering it closely by one or two dry ones, or, better still, by a rubber or other impermeable covering, will long retain both heat and moisture, securing free cutaneous circulation, and soothing in a most effective way the irritation in the chest. This may be maintained as long as requisite to relieve the patient, and then the body may be uncovered, a part at a time, rubbed dry and covered with a dry woolen blanket. By using elastic circingles over the compress they are adapted to the respiratory movements and any restriction in the movement of the ribs is beneficial by limiting the friction, pain and irritation in the pleura.

In the second stage, when inflammation has already set in, the same general measures of derivation toward the skin and hot bath or soothing derivative compress are still demanded though they may be substituted by more stimulating derivatives. The bleeding of the patient into his own vessels is sought in various ways. On the continent of Europe stimulating embrocations (essential oils, ammonia and oil, mustard, etc.) are applied to the limbs. In America and England similar agents are more commonly applied to the walls of the chest and dry cupping in the same region has been resorted to. Metallic cups with small mouths and having a capacity of about a pint each, have the air rarefied by plunging into each a spirit lamp, and, on its withdrawal, suddenly applying the mouth of the cup on the skin of the costal region previously well coated with lard. Another form of cup is made with a tube and stopcock in its otherwise blind end by means of which it is exhausted with a syringe after its mouth has been applied to the skin. In the absence of both a narrow mouthed glass tumbler may be employed, the air is rarefied by inserting into it a burning spill of paper or wood for a few seconds and on its withdrawal the cup is instantly inverted on the skin. If the animal is very hairy or very thin it may be necessary to shave the part, and smear with oil and even to select a very narrow mouthed cup. When applied the cup is cooled with water or otherwise and owing to the partial vacuum the skin is strongly drawn up into it and the blood accumulates in and under the skin. It may be kept on for half an hour at a time and with ten or twelve cups on one side the patient tends to profuse perspiration establishing a strong revulsion toward the skin, and great relief. In dangerous cases three or four applications may be required in twenty-four hours.

Next to this the mustard application is perhaps the safest and most valuable. The best ground mustard (black by preference) is made into a very thin pulp with tepid or cold (never hot nor boiling) water and rubbed in against the hair so as to soak the surface of the skin; it is then closely covered with paper and with a rubber or other impervious covering or, in default of better, with a close blanket and left on for two hours. By this time the skin should be thickened to the extent of at least a quarter of an inch and the derivation and relief will be very manifest.

Cantharides is sometimes used but like most other severe irritants, is liable to induce sympathetic irritation in an already severely inflamed pleura, and thus to obviate all benefit. Cantharides is also liable through extensive absorption to irritate the kidneys. To counteract this Bouley gave ½ drachm doses of camphor with alleged good effect.

Some practitioners make local applications of hot water and of aqua ammonia (confined) but unless very closely watched these are liable to destroy the hair follicles and produce permanent blemish.

The hot air, steam bath, and hot compress have the advantage over the mere irritant derivatives that their action is from first to last soothing and free from all risk of inducing sympathetic irritation and yet as derivatives they are eminently efficient. Next to them in safety and efficacy comes dry cupping.

The irritant derivatives are often the most valuable, but must be used with great judgment. They are always dangerous when the pleural inflammation runs very high and when the local irritation and suffering are specially acute. Under such circumstances it is usually desirable to adopt other measures to moderate the severity of the inflammation, and to fall back on baths, compresses and cups until the irritation is alleviated before vegetable or animal vesicants are resorted to. In acute and severe attacks these latter are especially applicable to the early stages before the inflammation has been fully formed, or after the stage of free effusion has set in.

With high fever and no benefit from hot local applications, cold irrigation or refrigerant compresses to the walls of the chest, have proved useful, but considering the rôle filled by cold in causation and the suggested relation between pleurisy and rheumatism this is not to be followed as a general practice.

If the patient has been a hearty feeder and if there is evident costiveness a purgative (aloes or sulphate of soda) is often desirable at the outset, but if the disease is of a low type this is always dangerous, owing to susceptibility of the intestinal mucosa and it is safer to correct constipation by injections or at most by a pint of olive oil.

When the suffering is very acute and is aggravating the fever, a hypodermic injection of morphine will often greatly relieve and even favor a revulsion of blood toward the skin, but as it tends to suppress the action of both bowels and kidneys it should be avoided unless it seems absolutely necessary, and above all it should not be given by the stomach. Cocaine hypodermically may be used to relieve pain.

Both fever and suffering can sometimes be greatly relieved by large doses (2 drachms 3 or 4 times daily) of salicylate of soda, which again suggests a close relation of the disease to rheumatism. Acetanilid or phenacetin may be used to fill the same indication.

Next come the questions of alkaline and diuretic treatment. Some cases do well if given nitrate of potash freely in the drinking water. Some prefer the alkaline diuretics, such as acetate of potash or ammonia, bicarbonate of potash or soda, biborate of soda, or the vegetable diuretics such as colchicum, squills, etc. Fraënkel found that, while comparatively ineffective alone, these proved most efficient (in man) when combined with cinchona or other bitter. The hint should be useful to the veterinarian. Diuretics in the stage of effusion should be pushed as far as the strength of the patient will warrant.

Friedberger and Fröhner recommend pilocarpin, and no agent produces an equal secretion from the natural emunctories and an equal tendency to reabsorption. It is however so profoundly exhausting that it must be used with the greatest judgment and caution.

Digitalis has often an excellent effect. Though not primarily a diuretic, it is a powerful tonic of the heart and circulation, and by increasing the blood tension it usually produces a free flow of urine. In combination with the diuretic salts it may be used from the first but it is especially valuable, after effusion and when attention must be given mainly to securing reabsorption. Care is demanded that we avoid its cumulative action, and in place of continuous large doses, a strong infusion applied over the loins will sometimes have a good effect. It may also be combined with bitters and even with ferruginous tonics in the advanced stages.

In combination with neutral salts and digitalis, iodide of potassium would seem to be indicated. Results however do not show a great superiority to other diuretics in favoring absorption.

Tincture of iodine, painted upon the chest over the affected parts, and repeated until tender, acts more or less as both a derivative and deobstruent. A liniment of iodide of potassium and soap is a convenient form of application.

The inunction of the chest walls with mercurial ointment has strong advocates both among physicians and veterinarians, and is combined in such cases with the exhibition of calomel internally. Unless the good effects are shown in a day or two it may well be abandoned.

When effusion becomes dangerous through excess, and in advanced cases when it fails to yield to medicinal measures thoracentesis is called for. (See under _hydrothorax_.)

PLEURISY IN CATTLE.

Milch cows and work oxen most liable. Causes. Damp buildings and
locations, sudden transitions from heat to cold, exposure when
fatigued, etc. Symptoms, rigor, reaction, cold horns and limbs, later
hot, excited pulse, catching breathing, hyperthermia, 104° to 105°,
tender chine and intercostals, friction sound, later dulness,
creaking, weaker murmur, subacute cases often tuberculous, effusion
unilateral, chronic cases. Lesions, as in horse with superficial
marbling of lung. Treatment, laxative, warm drink, compresses,
derivatives, sedatives, diuretics, heart tonics, diuretics,
thoracentesis.

This is not common in young growing cattle, but is more frequent in milch cows and work oxen. It is due to the same causes as in the horse, and especially to chills when heated, damp buildings and locations, cold draughts between open windows or doors, and cold storms. The greatest danger comes from hot, close stables, like many distillery stables, approximating to the temperature of the animal body and from which the stock are suddenly turned out of doors, or shipped by car or boat with a temperature near zero, and above all if furnished ice water to drink. Such animals taking no exercise to increase the circulation and heat, are especially liable to shiver and contract illness. Rigors too are easily induced in animals standing in hot buildings, when, in connection with the cleaning, an adjacent door is thrown wide open or two on opposite sides of the house. Working oxen heated with exercise and then exposed to extreme cold and compulsory inaction are endangered.

_Symptoms._ The attack is manifested by the same general symptoms as in the horse. The rigors are often very well marked, especially over the shoulder; the tenderness of the chine and intercostal spaces is striking; the breathing is catching but there is rarely the same restlessness as in the horse; the bowels are costive, appetite and rumination impaired or suspended, and the paunch is often distended with gas. The tenderness of the intercostal spaces, the friction sound of the pleura, and the maintenance of the respiratory murmur and the normal resonance of the lung, become the ultimate diagnostic symptoms. The pulse may be 70° and upward, the temperature above 104° to 105°. In some insidious cases indeed the fever is very slight and besides the general wasting of the animal, the indications obtained by physical examination alone enabled us to recognize the malady. Tuberculous pleurisy which is very common in cattle is to be suspected in such cases.

Effusion is recognized by the dulness of the lower part of the chest up to a certain line, and often unilateral, by the softer pulse, by the dilated nostrils, or open mouth, the contracted facial muscles, by the glazed eye, and anxious expression, by oppressed breathing and often by engorgement under the chest and in the limbs.

When the disease lasts over ten or twelve days it tends to pass into the chronic form. Or a chronic pleurisy of a subacute type may begin _de novo_ and pursue an insidious and latent course.

If the disease commences as a subacute affection there may have been for a month, capricious appetite, general ill-health and falling away before any other symptom is noticed. Now the breathing is manifestly excited, a small, short cough is heard at intervals, the pulse is accelerated but weak, and pinching auscultation and percussion detect unequivocal signs of pleurisy. From this the symptoms become more decided though for a length of time they are very slight, the animal meanwhile becomes increasingly emaciated, and perishes ultimately in a state of great weakness. Such insidious cases are always to be suspected of tuberculosis.

The _post mortem appearances_ resemble those of the horse. The surface of the lung beneath the diseased portions of pleura, however, often presents a marbled appearance from the infiltration of the areolar tissue between the adjacent pulmonary lobules. The organization of the false membranes begins on an average about the tenth day.

_Treatment._ The same general principles must be followed as in the horse. Bleeding can rarely be employed, partly because the disease so often assumes a subacute form, and partly because when first seen considerable effusion has often already taken place and severe depletive measures are thereby contraindicated.

A laxative dose (1 ℔.) of sulphate magnesia, may be given in warm gruel, and the same means by compresses, hot fomentations and counterirritation adopted, and the same sedative and diuretic medicines given as in the horse. In the advanced stages and in the low types of the disease the stimulating diuretics (sweet spirits of nitre, and liquor of the acetate of ammonia) and vegetable and mineral tonics are especially indicated. The diet in these last types must be nutritive, laxative and easily digested.

Tapping of the chest is equally applicable as in the horse, (_see Hydrothorax_.)

In the chronic forms everything is to be done to support the general health whether by food stimulants or tonics, and counterirritants may be applied several times.

PLEURISY IN SHEEP.

Causes, exposure, after clipping, washing in cold weather,
alternations from hot buildings to cold fields, shedding of the wool.
Symptoms, hyperthermia, troubled breathing and pulse with catching
inspiration, tender intercostals, friction sound, and signs of
effusion. Treatment, preventive, shelter, febrifuges in food or water,
aqua ammonia to sides.

The causes of pleurisy in sheep may be largely included in the general statement—exposure. Cold washing and exposure after clipping is especially injurious. Devieusart saw 300 cases of pleurisy and thirty deaths in a flock of sheep shorn in February. If kept secluded in warm buildings sheep may be shorn in midwinter, but any reckless exposure, and any sudden reduction of the temperature of the building is liable to be disastrous. Scab and other skin affections which lead to a shedding of the wool in inclement weather may also be the occasion of widespread attacks. Otherwise the causes are essentially those of the same disease in the larger animals.

The _symptoms_ resemble those of pneumonia, but with the peculiar sharp, short arrest of the inspiration, and the marked tenderness of the intercostal spaces as above described. The cough is short, dry, hacking and infrequent or suppressed as much as possible. Auscultation and percussion signs, corresponding to those found in other animals, are easily got in the newly shorn sheep. In the unshorn the wool must be parted and a stethoscope employed.

The _treatment_ is mainly _preventive_, or when the disease is present, of a general nature applicable to flocks. A warm barn, with pure air, blanketing, wet compresses, to which may be added extract of henbane, and nitrate of potash in the drinking water give examples of general medication. As a derivative, aqua ammonia and oil may be applied in lines on the chest exposed by parting the wool or generally on the shorn. Where the patient can receive the requisite attention further treatment should be on lines laid down for cattle.

DOG. PLEURISY.

Causes, exposure to cold, etc. Chill, reaction, disturbed breathing,
catching inspiration, rapid, hard pulse, hyperthermia, tender chest,
friction sound, later dullness at lower part of the chest in any
position. Treatment, as in pneumonia, with antirheumatics and
diuretics freely. Thoracentesis.

This is occasionally seen in the dog as the result of exposure, and like other diseases of the chest is easily recognized. It owns the same causes with pneumonia.

_Symptoms._ There is first dulness, shivering and some excitement of respiration. To this follow the more acute symptoms, the hard pulse, the rapid, catching breathing, the animal standing or sitting on his haunches, the open mouth, pendent tongue, the injected mucous membrane, the costiveness, but above all the tenderness of the intercostal spaces, the early friction sound on auscultation, the pain and normal resonance on percussion, the muscular twitchings and the short, suppressed, painful cough. When effusion has occurred its amount may easily be estimated by turning the animal alternately on its feet, back and haunches, and observing how high the dullness extends in these various positions.

The same _treatment_ may be adopted as in _pneumonia_, with this difference that salicin may be given freely, and when effusion has taken place active diuretics are specially indicated, and hence tincture of squills (a teaspoonful) may be made to replace the nitre. In advanced and obstinate cases, or where danger exists from rapid effusion, the liquid may be drawn off with a cannula and trochar as in other animals.

PLEURO-PNEUMONIA. BRONCHO-PNEUMONIA. BRONCHO-PLEURO-PNEUMONIA.

Though we often meet with typical forms of _bronchitis_, _pneumonia_ and _pleurisy_, it is much more common to find them combined more or less with each other. Thus combined inflammation of the bronchial tubes and pulmonary substance is frequent; inflammation affecting both the lung and its investing pleural membrane is no less common; and cases are seen in which all three structures are involved. These conditions are to be recognized by the presence of the symptoms of both the coexisting maladies but particularly by the indications furnished by touch, auscultation and percussion. The predominance of one disease over another will decide the nature of the treatment which must be adapted to the peculiar character of each case whether _mainly bronchitic_, _pneumonic_, or _pleuritic_. It is these mixed cases that test the ability and judgment of the practitioner as he must carefully individualize each case, ascertain the different parts affected, the grade of the inflammatory action, the nature of the attendant fever, the presence or absence of epizootic influence, etc., and having all these conditions in view must apply remedial measures accordingly.

It must be evident that particular directions cannot be supplied for all of these cases. General principles only can be inculcated and their adaptation to the varied phases of different cases left to the judgment of the student.

HYDROTHORAX.

All animals liable. Causes, pleurisy, obstruction to pulmonary or
intercostal veins, heart disease, Bright’s disease, anæmia, parasitic
or otherwise. Effusion reddish gray or clear straw color, inflammatory
and dropsical. Symptoms, troubles of respiration, as a secondary
disease complicated by dropsies elsewhere, signs of hydrothorax
without fever, shedding of hair. Treatment, diuretic, tonic,
derivative, thoracentesis, trochar and cannula or aspiration, point of
election for puncture, method, asepsis, drainage by aspirator, or into
an antiseptic solution, eligible cases, dangers attending
thoracentesis, shock, rupture of false membranes and lung, infection
of pleura, injection of antiseptics.

_Hydrothorax_ or _water in the chest_ is common to all domestic animals. It is as we have seen one of the most ordinary results of _pleurisy_, and may persist long after that disease has disappeared. It likewise occurs independently of inflammation as a dropsical effusion. Thus when the return of blood by the bronchial, pulmonary or intercostal veins, is hindered by any cause such as tumors in the bronchial glands or subvertebral region a passive effusion may take place through the coats of the vessels. In imperfection of the mitral valves the regurgitation of blood in the pulmonary veins during each cardiac systole equally causes such transudation. Chronic disease of the kidneys (Bright’s disease) with the retention of effete and injurious materials in the blood leads to dropsy of the chest as in other parts of the body. Again in many debilitated conditions parasitic and otherwise, with a tendency to general dropsy the chest participates and a collection of fluid takes place in the pleuræ.

The nature of the contained fluid will vary according to the conditions in which it has been effused. If the result of inflammation there are the different stages already indicated: _first_, of a yellow citrine color or red from contained blood; _second_, grayish and muddy either from contained pus or other changes taking place in the fluid; and _third_, clear limpid and translucent as seen in the later stages. If merely a dropsical effusion the fluid is watery clear and translucent or with a slight straw color. The inflammatory effusion contains fibrine or fibrinogenous elements, is associated with the formation of false membranes, and though it may remain fluid so long as it is retained in the chest, it coagulates rapidly when withdrawn. The dropsical effusion rarely contains fibrine, and then only in very small amount, and it does not coagulate when drawn off from the chest. The inflammatory effusion usually contains a greater proportion of common salt, phosphates or albumen than exist in the blood, and floating granules, particles and cell forms, none of which conditions characterize the dropsical effusions. The most prominent feature of the inflammatory effusions is thus seen to be their power of coagulation, by virtue of the contained fibrine, when exposed to the air.

_Symptoms._ When a sequel of pleurisy it is manifested by the symptoms already mentioned under that head as indicating the occurrence of effusion.

The dropsical cases may come on rapidly and present all the signs of troubled respiration together with the results of auscultation and percussion that characterize rapid inflammatory effusion but without the fever and acute symptoms of pleurisy. More usually it comes on insidiously, the lung accommodates itself to the gradual increase of the fluid and it is only when the accumulation has become excessive that the symptoms become prominent. In heart or kidney disease the filling of the legs and infiltrations of the eyelids and of the skin beneath the chest and abdomen are precursors or early concomitants of the disease, but in all cases the accumulation in the chest is to be measured by the height of the line of dulness on percussion and the extent of chest surface giving forth no respiratory murmur on auscultation. As the liquid rises on both sides of the chest, as it always does in such cases in the horse, the breathing becomes short and labored, being chiefly effected by the action of the diaphragm and the flanks—the ribs moving only slightly. The nostrils are widely dilated with each breath. The previously existing want of vigor and energy, the weak pulse, the poor appetite and the pallor of the mucous membranes become aggravated; the animal becomes very weak and prostrate, the loins insensible, the permanently tucked up flanks labor tumultuously, the loins rise in inspiration, the face is pinched and haggard, the eyeballs glazed and protruding, and death is preceded by the same general symptoms as in rapid effusion after pleurisy. A prominent feature of this, as of all dropsical affections, and one usually seen in the hydrothorax of inflammation as well, is the ease with which, even at an early stage of the disease, the long hairs of the mane and tail may be pulled out. In many cases they come out in handfulls when the comb or the fingers are passed through them.

_Treatment._ The treatment must be of the actively diuretic kind recommended for the effusion of pleurisy. It is modified however in one respect. The inflammatory action having subsided or nearly so and the condition being now essentially one of weakness a free use of tonics is demanded. Many a patient dies in such circumstances from the actively depletive treatment to which it has been subjected and the want of attention to its need of generous diet and other support. The agents prescribed for the advanced stage of pleurisy may be given, or the digitalis or other diuretics and bitters may be combined with iodide of potassium in one or two drachm doses, the amount being apportioned to the strength of the animal. Iron in the form of sulphate, perchloride or iodide may be freely given combined with gentian, quassia, or other vegetable tonic, and above all a liberal and easily digested diet must be allowed. Good will sometimes result from repeated applications of strong iodine ointment to the sides with active friction.

When the condition is dependent on disease of the heart, kidney or other organ, these must be attended to according to their special requirements.

Disconnected from such complications hydrothorax will often give way to an active treatment similar to that indicated above. In some cases however our only hope of even temporarily prolonging life lies in the operation for drawing off the fluid.

=Tapping the chest= or as it is technically called =thoracentesis= or =paracentesis thoracis= has proved sufficiently successful in the lower animals to warrant its continuance in cases that resist other modes of treatment. It is highly probable that the larger proportion of unsuccessful cases is due in great part to the hopelessly advanced stage at which it is often had resort to, to the insufficient precautions adopted in its performance, and to the want of appropriate dietetic and medicinal treatment. Dr. Bowditch’s treatment by _paracentesis_ saved in the human subject at the rate of about two patients in five and we ought by availing of similar precautions to reach the same standard.

The cannula employed in veterinary practice is a silver tube two inches in length, a quarter of an inch in diameter and furnished with a shield of the same metal at one end. The trochar by which it is introduced is of steel or brass. To carry out Dr. Bowditch’s system the operator must supply himself with a syringe of a somewhat smaller bore and an intermediate brass piece of a size adapted to fit accurately into the cannula and supplied with a stopcock. By an instrument of this kind the fluid can be drawn off by means of the syringe without any risk of the introduction of ærial germs which always tend to induce suppuration and even a putrefactive decomposition in the contained fluid.

The point selected to operate on is, in the horse, ox or dog, in front of the anterior border of the ninth rib, at its lower end or close to its union with the cartilage. The point of the trochar should be directed slightly upward and forward to avoid the possibility of injuring the diaphragm. The skin is first rendered aseptic by shaving, followed by a thorough soapy wash and a free use of mercuric chloride solution (1:500). It is then pricked with a lancet, then drawn aside that the wounds in the skin and muscles may not correspond after the cannula has been withdrawn. The trochar is then pushed steadily through the intercostal space till all obstruction has been overcome, when it may be concluded that the pleural sac has been reached. The trochar is now withdrawn and the fluid allowed to flow from the cannula until there is presumably some risk of the introduction of air, when the brass piece is to be applied and the remainder drawn off with the syringe or aspirator. As a substitute for the aspirator a caoutchouc tube, eighteen inches long, put on the cannula or needle and having its lower end plunged in a solution of boric acid will prevent the entrance of germs. A prob has often to be introduced to prevent plugging of the cannula by floating false membranes, and a new puncture in a different place may be necessary. In the case of excessive accumulation it is often advisable to draw it off at two operations, as recommended in large abscess of the pleura and for the same reasons. The need for such a precaution will be understood when it is stated that in bad cases the chest contains as much as six or seven ordinary stable bucketfuls of the liquid. If, however, it is limited in amount it may be all withdrawn at once.

The most successful cases in the horse have been upon young, vigorous animals, from four to eight years old, during the first month of illness, and where the pleurisy has been confined to one side.

Dr. Bowditch lays down the following rules for the adoption of paracentesis in man (_Clinical Medicine_, by Prof. W. T. Gairdner):—

“I now never operate unless I find some distension or rounding out of the chest, and filling up of some of the intercostal spaces, so that the chest presents a uniform curve, and not alternate depressions and elevations as in the healthy chest. I operate under the following circumstances when I feel certain there is fluid:

“1. When there is _severe permanent dyspnœa_—orthopnœa—however acute the disease if I find fluid filling the pleural cavity, or nearly filling it.

“2. When there are occasional attacks of orthopnœa threatening death, even if there be not sufficient to fill more than half of the cavity. If the fluid seems to be the cause of the dyspnœa I operate, because occasionally I have lost a patient while waiting for more extensive physical signs. This rule I apply to acute and chronic cases.

“3. I use the trochar after three or four weeks of ineffectual treatment, without any absorption being produced.

“4. In chronic idiopathic hydrothorax, a latent pleurisy with simply physical signs to indicate _extensive_ effusion, but when the rational signs are either very slight or none at all save a general malaise and weakness.”

The use of iodide of potassium and vegetable and mineral tonics must be perseveringly employed and the strength further supported by a generous diet, to secure the animal against the dangers of extreme prostration, of suppuration, or other undesirable conditions of the exuded product.

Among the dangers attending thoracentesis are fainting as a result of shock on the sudden withdrawal of so much liquid, rupture of the false membranes, and even of the enclosed lung tissue or of blood vessels, under the sudden expansion of the partially collapsed lung confined by the investing false membrane, and the introduction of pus or septic germs into the pleural cavity. To obviate the first named dangers tight bands (circingles) around the chest will give support and limit sudden expansion. In case of excess of liquid the withdrawal of one-half or two-thirds at a time will allow opportunity for accommodation. Hæmorrhage may be met by the internal use of chloride, sulphate or nitrate of iron, matico, hamamelis or tannic acid, and a weak solution of boric acid or other antiseptic agent may even be injected in small amount into the pleural cavity.

In obstinate and chronic cases the injection of a weak solution of iodine and iodide of potassium is often of service. In other cases a normal chloride of sodium solution (previously sterilized) may be introduced as soon as a partial evacuation causes uneasiness, and by a succession of such evacuations and injections the residuum liquid may be rendered clear and largely aseptic on a single occasion.

In the smaller animals the selection of the most dependent part for insertion of the trochar is not so essential, as the body may be turned to facilitate the drainage.

On completion of the operation the wound may be again treated antiseptically and coated with aristol or collodion.

PNEUMOTHORAX. AIR OR GAS IN THE PLEURA.

Causes, decomposition of liquid effusion, perforation from a
bronchium, the stomach, a thoracic wound. Symptoms, metallic tinkling,
splashing, succussion, drum-like resonance, suppressed respiratory
murmur, distance of cough sound, distress, anxiety, dyspnœa, bulging
intercostal spaces, sometimes a wound. Treatment, closure of wound,
calmatives, aspiration of gas. Treatment for pleurisy.

The collection of air or gas in the cavity of the pleura has already been noticed as coexisting with liquid effusion in some cases of advanced pleurisy. It may arise from other causes, among which may be noted: 1. When a mass of pulmonary tubercle connected with a bronchial tube has opened into the pleural sac. 2. When a communication has been established between the pleural cavity and the alimentary canal, as in combined rupture of the stomach and diaphragm, or of the double colon and diaphragm. 3. When a rib is fractured and the broken end penetrates the lung tissue and opens into one or more small bronchial tubes. 4. When a wound has been inflicted penetrating the walls of the chest and forming a valvular orifice through which air is drawn inward during each inspiratory act, but out of which it cannot pass when the thorax collapses.

The amount of gas present may be extremely slight, or in a case such as that from a valvular wound it may cause complete collapse of the lung, filling up the entire half of the thorax and bulging into the opposite half.

The _symptoms_ are often very obscure. If with liquid the metallic tinkling after rising, in small animals the splashing when shaken and the other sounds of auscultation and percussion will point it out as described under _pleurisy_. In the case of a broken rib the distortion, swelling and tenderness, will lead to suspicion. A penetrating sound will be sufficiently evident, and in the case of tubercle previous cough and ill-health will have been manifest.

The specific signs of uncomplicated pneumothorax are: 1st, A drum-like resonance on percussion over the seat of the gas, usually at the upper part of the chest; 2d, A partially suppressed or distant respiratory murmur over the same area; 3d, A muffled or suppressed sound of the cough; 4th, Sometimes, especially if the gas is abundant, prominence of the chest on that side; 5th, There are also more or less distress and anxiety, difficult breathing, quick, weak, rapid pulse, and other signs of illness.

Some cases of this kind recover spontaneously or with the liquid effusion with which they are associated; in traumatic cases the wound is sometimes sealed up by a pleuritic exudation which here becomes a curative process; while in some examples of valvular wound of the lung or walls of the chest death may ensue in a period varying from a few minutes and upwards to weeks.

_Treatment_ is limited to the prevention of the ingress of air through an external wound where that exists; the employment of opiates and other agents to moderate attendant suffering; to measures calculated to moderate the intensity of resulting pleurisy, and, in cases where there is imminent danger from accumulation of gas, to the puncture of the chest and the careful withdrawal of the gas by aspiration. If necessary sterilized air may be made to replace the aspirated gas.

PYO-PNEUMOTHORAX, EMPYEMA.

Causes, septic cocci entering through wound or blood. Symptoms, those
of hydrothorax, with prostration, fœtor, and it may be issue of pus.
Treatment by antiseptic injections.

A purulent fluid in the pleural cavity may be found in ordinary pleurisy, but is much more likely to supervene in traumatic forms, in which the pus cocci reach the cavity through the wound of the bronchia, alimentary canal, or chest walls.

The symptoms are essentially those of pneumothorax, with greater prostration, and in certain cases a distinct feverish smell or fœtor of the breath, or the escape of pus through a wound. In treatment the difference from pneumothorax is mainly in the antiseptic character of the injections and the freer employment of stimulants and tonics. Salt, salicylic acid, borax, peroxide of hydrogen, aluminium acetate, or potassium permanganate solutions may be used. Tonics (quinia) and antiseptics (sulphites, salicylates, iron) may be given.

CHRONIC PLEURISY.

Animals liable. Causes, irritation through effusion and exudate acting
on susceptible pleura, or by other disease products in lung or pleura.
Unhygienic surroundings and management predisposes. Frequent chills in
cold water. Symptoms, unthriftiness, easily blown, fatigued, or
sweated, cough, paroxysmal under exertion, pallor of mucous membranes
becoming congested on slight exertion, difficult breathing when
recumbent, percussion and auscultation signs of pleurisy and
hydrothorax. Lesions, great liquid effusion, clotting on exposure,
with much albumen and cell forms. False membranes partially organized.
Treatment, tonic, diuretic, derivative, diet nourishing,
counterirritants, paracentesis.

In all domestic animals acute pleurisy may merge into the chronic form, the irritation being maintained by the presence of the residuum liquid and the false membranes and adhesions which interfere with the free dilatation of the chest. The pleura too, having been once inflamed, retains an increased susceptibility to such disturbing conditions. In other cases the affection is symptomatic of other chronic affections, as tuberculosis, glanders, and neoplasms of various kinds. It has been seen especially in old, weak and debilitated subjects, kept in confined, impure stables or habitually exposed to undue cold and damp. Hence dairy cows in unhygienic conditions, and hunting dogs, which plunge in water when heated, are among the most frequent victims.

_Symptoms_ are often obscure. The affected horse may be bright and lively, showing little respiratory disturbance unless under exertion. Yet there is a general appearance of unthriftiness, with erect, dry hair, hidebound, and a small, dry cough. Under work there is hurried breathing, early exhaustion, ready perspiration, and aggravation of the cough which then occurs in paroxysms. Auscultation and percussion give characteristic signs according as there may or may not be false membranes or effusion at particular points. It is usually bilateral in horses, unilateral in other animals.

In cows in addition to the corresponding symptoms, there is pallor of the mucous membranes when at rest, quickly transformed into congestion under exercise, suppression of the milk, and weak heart beats unless when excited. In the advanced condition the animal has difficulty of breathing when recumbent on the sound side and subcutaneous infiltration is felt or seen beneath the sternum or in the limbs. The affected side shows an increased dimension, vertical and longitudinal, of the chest, and the intercostal spaces in their lower part bulge out and fluctuate.

In cows and indolent animals there may be a quiescent condition or very slow progress, but any violent exertion is likely to give a sudden stimulus to the morbid process.

_Lesions._ The liquid effusion, usually unilateral, except in the horse may amount to 40 quarts in the latter animal, 30 quarts in the ox (Rigot), and 5 to 6 quarts in the dog. Unless there has been a recent sudden accession of inflammation it is of a pale straw color, with, in the dog, a slight rosy tinge. It clots loosely on exposure to the air and contains a large amount of albumen and few cell forms. The false membranes are thick and white at some points and red and vascular at others. In the main they are completely organized. The lung is more or less collapsed and the right heart dilated and attenuated.

_Treatment_ must be in the main tonic, diuretic and derivative. Food must be nourishing, digestible and in liberal amount; diuretics and bitter tonics with digitalis and, (if there is little fever) preparations of iron are to be pushed as far as the strength will allow; and the counterirritants applied to the sides of the chest a number of times in succession. Iodides may be used internally and externally, and _paracentesis_ must be employed unless early improvement is manifested.

PLEURODYNIA.

Definition. Symptoms, stiffness, pointing of fore limb, catching
inspiration, tender intercostals, less fever, cough, and hardness of
pulse than in pleurisy, no friction sound nor signs of pleuritic
effusion. Treatment, antirheumatic, derivatives, colchicum, alkalies,
salicylate, salol, phenacetin, warm (steam) bath, warm building and
clothing.

_Definition._ Rheumatism of the intercostal muscles. This has been occasionally observed in the horse, and is liable to be mistaken for pleurisy, which it closely resembles in its symptoms. There are the same stiffness of the fore limb on the affected side, the same short breathing, the same fixed and inactive appearance of the ribs, and the same extreme tenderness on pressure as in pleurisy; but the high type of fever, the cough and the full hard and accelerated pulse are usually absent; the tenderness tends to shift from one point to another, there is no shivering nor friction sound in the early stages, and no subsequent absence of sound and deadness on percussion over the lower part of the chest as result from effusion. When associated with fever it is very difficult to distinguish from pleurisy, and its recognition can only be made by these physical signs just mentioned.

_Treatment._ This must be the same as in rheumatic attacks in general. Rub the chest actively and repeatedly with a mixture of equal parts of spirits of turpentine, laudanum and olive oil, give ½ drachm doses of powdered colchicum daily and bicarbonate of potass freely in the water drank. Or give four times a day 2 drachms of salicylate of soda, or 1 drachm of salol, or phenacetin. A warm building and warm clothing are essential elements in treatment.

BRONCHIAL ASTHMA IN THE DOG.

Definition. Pathology, neurotic origin, bronchial spasms, swelling of
mucosa, fibrinous inflammation of bronchioles, Berkart’s
streptococcus, irritants formed in indigestion, overfeeding,
inactivity, plethora, constipation. Symptoms, obesity, sluggishness,
recurrent paroxysms of dyspnœa, hard cough, tense abdomen,
constipation, piles, depilation of skin, tartar covered teeth, fœtid
breath. Retching, vomiting, a glairy mucus, emaciation may follow.
Lesions, emphysema, fatty deposits in mediastinum, old standing
diseases of the heart, lungs and digestive organs. Treatment,
antispasmodics by lungs or rectum, stramonium, nitre fumes, emetic,
purgatives, vegetable diet, exercise, sedatives, blisters. Asthma in
the horse.

_Definition._—A neurotic affection mainly affecting the pneumogastric nerve, and leading to paroxysms of stenosis or constriction of the bronchioles and attacks of dyspnœa. In its initial stages it is associated with corpulence and disordered digestion, and later with congestion and swelling of the mucosa of the bronchioles, emphysema, and dilatation of the right side of the heart.

_Pathology._ Asthma is generally attributed to spasm of the bronchial muscles (Williams), and though recent observations have failed to sustain this it must be admitted that in the majority of cases it is of decided neurotic origin. Again it is attributed to erythematous swelling in patches of the bronchial mucosa, (Clark). Another theory is that it is a fibrinous inflammation of the mucosa of the bronchioles, the tenacious exudate blocking the tubes more or less completely and relief coming with a more diffluent secretion. Berkart found a streptococcus in the sputa which he supposed to be the final cause. Again it has been held to depend on the circulation in the blood of deleterious matters introduced during digestion. Again it has been attributed to a neurosis roused by constipation and the accumulation of irritant matters in the intestine. Whatever local conditions may be operative, there can be no doubt that in dogs it is almost exclusively confined to those kept indoors, overfed, without exercise, plethoric and constipated. The disease seems to originate in and persist by nervous disorder propagated from the digestive organs. A change of diet or any disturbing cause may bring on a paroxysm.

_Symptoms._ The disease is one of pet dogs, kept in towns, deprived of exercise, fresh air, and of the opportunity to relieve the bowels at will, and gorged with highly spiced meats, and sweets at least three times a day. Sluggishness and obesity are marked characteristics of the dog when first attacked though in the advanced stages the violence of the paroxysms and their frequent recurrence may have induced extreme emaciation.

The affection is usually ushered in by a cough, at first slight, but soon becoming frequent, hard and sonorous, as in the early stages of bronchitis. The cough becomes very troublesome and the breathing habitually labored, but at irregular intervals a paroxysm comes on which threatens death by suffocation. The dog stands or sits on his haunches with open mouth, pendent tongue and staring eyeballs, panting for breath, and has his condition aggravated by every change of position or other source of excitement. By the frequency and severity of the attacks may be estimated the danger of the patient.

An examination in the intervals of the attacks detects some disturbance of the digestive organs. The tense and distended condition of the abdomen usually manifests the existence of overloaded stomach and bowels, of indigestion, tympany and constipation. Piles are often present as a result of long continued costiveness. The skin is dry and unthrifty, and often in patches denuded of hair. The teeth are covered with tartar and the breath fœtid.

Retching is occasionally seen to occur during a violent access of coughing, but only a little glairy mucus is brought up.

The cough, hurried breathing, and paroxysms of dyspnœa become aggravated, the general health suffers largely, and death often ensues in a state of great weakness and emaciation.

On _dissection_ of such cases the lesions of various old standing diseases of the heart, lungs, or abdominal organs have been met with at times, and such disorders have doubtless assisted in maintaining and aggravating the asthma. The most constant lesions, however, are emphysema of the lung, and accumulations of fat in the mediastinum.

=Treatment.= 1st. =During a paroxysm.= This is confined to the administration of antispasmodics either by inhalation or as an injection to avoid the additional suffering of swallowing. Ether or chloroform may be inhaled from a sponge, but the employment of these should be guarded especially in advanced cases when besides the prevailing weakness there is reason to suspect structural changes in the heart. The same agents in doses of one, two or three teaspoonfuls, or laudanum in double that quantity may be thrown up as an enema, and may be combined with a couple of ounces of castor oil when costiveness exists. The fumes from burning stramonium or from burning brown paper which has been previously soaked in a strong solution of nitrate of potass, will in many cases suddenly cut short the paroxysm. If on the other hand there is reason to believe that the stomach is overloaded the attacks will often be suddenly cut short by giving an emetic. For this purpose a grain of tartar emetic may be shaken upon the tongue, or a dessert spoonful of wine of ipecacuan, or of antimony, poured over the throat. 2d. =In the intervals between the paroxysms.= Attention must be given to counteract any inflammatory action in the chest by which the disease may be maintained. Our chief object, however, must be to divest the animal of its superfluous fat and bring the digestive organs into a healthy condition. Unfortunately the propensity to fatten in some dogs seems to be a morbid condition. The food appears to be stored up as fat at the expense of muscular and other tissues even when the animal is kept on the borders of starvation. All flesh must be withheld and coarse vegetable fare alone allowed. A well boiled pudding (porridge) made with oatmeal or Indian corn meal, water and a little salt, with a small quantity of skimmed milk or buttermilk, is an excellent diet in such cases. The amount must be small, though the hitherto pampered favorite will rarely seek to fully replenish his stomach until he has forgotten his former extravagant habits.