Part 30

In favorable cases recovery takes place in one or two days. There is a return of life and appetite, a gradual improvement in pulse and breathing, the respirations becoming deeper and longer, and in a few hours all the more violent symptoms may have disappeared. With a more gradual improvement recovery may still be complete in four or five days.

Lesions. When the subject has died suddenly the appearances are essentially those of uniform engorgement of the pulmonary capillaries with blood. The general aspect is a dark red, varying from reddish brown to black, the darkest shades corresponding to circumscribed areas of actual hæmorrhage. In the worst cases the whole mass may appear like black currant jelly. The lungs do not collapse when the chest is opened, they are more or less friable at various points, and different portions will sink or float in (not on) water, according as it may be more or less airless. A dark liquid blood exudes freely from the torn or cut surface. Sections of the lung tissue hardened and examined under the microscope show the alveoli and bronchioles devoid of exudate, but having their cavities compressed and obliterated by the pressure of the swollen mucosa, and its investing blood clot. The heart is overdistended with fluid blood. In asphyxiated cases the general venous system is filled with black, liquid blood, and the serosæ spotted with petechiæ.

Nature. The nature of this disease is variously understood. It differs from inflammation in the absence of active cell proliferation, and migrations of inflammatory exudation, and of fever at all proportionate to the extent of the lesions. All these may and do supervene if the patient survives but they are practically absent for a length of time at the outset. Some attribute it to paresis of the vaso-motor centres for the lungs, as the result of their over stimulation and of the retrocession of blood from the chilled surface to the internal organs. But congestions caused by cutting the cervical branch of the sympathetic nerve or the sciatic plexus are not marked by a similar blood extravasation and destruction of tissue. The delicate structure of the lung tissue and the comparative absence of mechanical support will account for this in part, the great force of the circulation overloading the capillaries, under the impulse of the heart so closely adjacent, has doubtless a certain effect, and the venous nature of the blood thus forced into the lungs and calculated to arrest all normal function has a potent influence. If we add to this, for the over-exertion cases, the sudden advent into the circulatory stream of unchanged peptones and other ingredients of the portal blood of highly fed and plethoric animals we find a sufficiently pathogenic combination. In all acute cases however the adiposity, poor condition and susceptibility to speedy exhaustion must be given their full share of responsibility.

Treatment. Girths, saddles and anything else that may hamper the movement of the chest must be at once removed and the horse’s head turned to the wind, an active stimulant given and the legs well rubbed and loosely flannel bandaged. The nature of the stimulant is of less consequence than its prompt administration. Two ounces of chloroform, of sulphuric ether, or of sweet spirits of nitre; half a pint of whisky, brandy or gin; or a pint of any of the more stimulating wines may be given, diluted in warm water so as to remove their irritating qualities. A drink of warm gruel will often go far to restore warmth to the surface and to unload the overtaxed lungs. Frequent large injections of warm water have a similar effect. Active hand rubbing of the legs and the wrapping of them loosely in flannel bandages previously warmed at the fire is equally valuable. If a roomy, well ventilated, loose box can be obtained the horse should be led to it gently and a light but warm rug placed upon the body. Valuable derivation may be obtained from pediluvia, the feet and legs up to the knees and hocks being put in buckets of water as hot as the hands can bear, and at the same time actively rubbed. If this is impossible the legs may be wrapped in bandages and wet with hot water every few minutes. Or this soothing derivative agent may be applied as well to the surface of the chest. A blanket wrung out of hot (nearly boiling) water until it no longer drops is wrapped round the body and covered up with two or three dry rugs. A second smaller rug is wrung and placed on the neck and covered by a sufficiency of hoods to keep in the heat. The legs are meanwhile hand rubbed and bandaged and the other measures above recommended carried out to restore the circulation in the surface and extremities. The time honored practice of bleeding freely from the jugular vein is one of the most effective means of relieving the overcharged heart and lungs, and should be resorted to at the earliest possible moment. The blood will at first flow in a small, dark stream, but as the circulation obtains relief the jet will increase in volume and the general symptoms will improve. From four to six quarts may be taken with advantage from an ordinary horse. This is not a pneumonia but an overloaded heart and lungs, threatening speedy death and which the abstraction of blood promptly relieves.

The longer the bleeding is delayed the less effective it is. It should not supersede the other measures already recommended. There is no real paradox in both bleeding and giving stimulants in such a case, as the essential condition is one of weakness, and if the abstraction of blood has been of use in relieving the clogged heart and lungs, the depression under which these have labored may be still further overcome by agents calculated to rouse their suspended vitality.

Trasbot strongly recommends large doses of tartar emetic and iodide of potassium to reduce the blood pressure in the lungs, an advice which will be received with hesitation by those who dread the already paretic condition of the heart. His combination of iodide of potassium with digitalis will be more confidently resorted to. One drachm of the former may be given with a half drachm of the latter twice daily.

With the advent of marked fever and other signs of pneumonia, the treatment for that disease should be resorted to.

PULMONARY ŒDEMA.

Causes, pneumonia, extra force of right heart or weakness of left, insufficiency of mitral valves, deflection of blood by obstruction in one portion of lung, pressure of tumor on pulmonary veins. Malignant œdema. Malignant catarrh. Bright’s disease. Anæmia. Parasitism. Symptoms, abnormal heart sound, or urinary secretion. Parasitism. Percussion shows flat sound auscultation lowered, respiratory murmur, heightened blowing. No crepitation. Expectoration serous. Prognosis grave. Treatment, attacks primary disease. Posture. Elimination. Dry capping. Heart tonic.

A dropsy of the lung tissue may supervene in weak conditions, in the course of inflammatory disease of the lungs; it may also depend on an imperfect balance in the forces of the right and left heart respectively, which leads to the habitual throwing of blood pressure back upon the lungs. Still more frequently the congestion and dropsy depends on insufficiency of the mitral valves by reason of which a reflux of blood toward the lungs takes place at each heart beat. The pressure of tumors on the pulmonary veins may have a similar action. Obstruction of circulation in one portion of lung may cause an extra blood pressure on an adjacent one, and œdema so caused may be found especially in cattle and pigs in which the interlobular connective tissue is specially abundant. This may be seen in miliary tuberculosis in cattle, and it probably contributes to produce the extraordinary liquid collections that characterize lung plague. In cattle also malignant œdema may affect the lung, and an œdematous condition is sometimes met with in malignant catarrh. Bright’s disease is another cause, the uræmic dropsy finding a favorite seat of election in the loose lung tissue unsupported by solid tissues. The anæmia resulting from parasitism like distomatosis may similarly affect the lung.

The symptoms of pulmonary œdema will usually be complicated by those of the affection causing it. Thus modification of the first heart sound or of the urinary secretion, or the existence of parasitism, would furnish valuable indications.

The physical signs of lung disease vary. If pneumonia is present it is betrayed by its characteristic symptoms. In the absence of inflammation there is dullness on percussion over the affected area, and on auscultation an absence of the respiratory murmur, and perhaps abnormal clearness of bronchial, cardiac and other sounds from deeper parts. It differs from pneumonia in the absence of fever and of any crepitation surrounding the consolidated portion. The expectoration is serous or watery, rather than rusty or purulent.

The prognosis is always grave in proportion to the incurable nature of the primary disease. Chronic valvular or Bright’s disease, miliary tuberculosis or malignant tumors would render the case hopeless, while in acute pneumonia, or nephritis or parasitism there may be some hope. The treatment will largely consist in the therapeutics of the primary disease, yet we may also seek to relieve the dangerous symptoms of œdema. The frequent change of position may serve to limit hypostatic accumulation. Diuretics or purgatives in strong patients will favor absorption. Pilocarpin more than any other agent secures temporary absorption but cannot be continued owing to its depressing effects. Digitalis is often valuable in improving the heart’s action, and acting freely on the kidneys. Dry capping on the chest acts as a derivative.

ATELECTASIS. COLLAPSE OF LUNG.

Atelectasis in bronchitis, congenital, etc. Airless condition in the absence of exudation. Causes, congenital persistence in butcher animals. Blocking of air tubes by exudate—ball valve. Desquamation of ciliated epithelium. Compression by hydrothorax, pneumothorax, and false membrane. Symptoms. Percussion flatness, juvenile respiration elsewhere, blowing sounds loud. Drum-like sounds on emphysema and pneumothorax. Cyanosis. Lesions, depressed, flesh-like, non-crepitating lobules or lobuletes, sink in water, dilatable. Treatment, rouse respiratory centres, douches, cold and warm, slapping, electricity, forced inspiration, diet, massage. Treat attendant disease.

This has been already referred to as a result of bronchitis, but it deserves special mention as a sequel of that affection, and in various domestic animals, as an independent condition. The condition is one of consolidation of lung by the complete exclusion of air, but without any infiltration of its substance by inflammatory exudate or dropsical effusion. The tissue remains in its normal state apart from the fact that its bronchioles and air sacs are undilated. The affected portion has a solid dark fleshy appearance. The collapsed portion often represents one lobule or group of lobules which communicate with a single bronchium.

Causes. In some instances the conditions remain from birth, the lobule never having been called into use. This is seen especially in cattle and other meat producing animals, in which active breathing is systematically suppressed in the interests of rapid growth and the deposition of fat. In the improved breeds the lungs remain larger than the exigencies of the life demand, and large portions remain out of use. In bronchitis the condition is acquired, and is mainly dependent on the blocking of a bronchial tube with tenacious mucus or a desiccated mass. The pathological lesions of bronchitis favor this since one of the earliest changes in the inflamed mucosa is the desquamation of the columnar epithelium. This removal of much of the cilia and the paralysis of much of what is left annihilates for a time the normal method of clearing away the secretion, and this being now produced in excess blocks the tubes. This secretion virtually acts like a ball valve in favoring the exit of the air during the convulsive expiration of coughing, and hindering its entrance during the succeeding inspiration. The bronchia and bronchioles decrease in size to near their termination, so that, as forced out in coughing, the secretion enters the larger tube and allows the exit of air, which as drawn back in inspiration it enters the smaller tube and closes it against any possible ærial entrance. Mendelssohn and Traube demonstrated this action by introducing a shot into a dog’s lung, and in two days the left lung was found collapsed and the right one the seat of complementary emphysema. The violence and frequency of the cough therefore bears a ratio to the occurrence and extent of atelectasis. Other causes are the compression of the lower lobes of the lung by hydrothorax, by pneumothorax (developed by lacerated lung or perforated chest wall) or by a false membrane contracting in process of organization.

Symptoms. As a congenital condition in the improved meat producing animals the condition is rarely recognized in life and cannot be said to be a defect. The collapsed lobule being farther removed from the air may be a more favorable field for the growth of pathogenic bacteria, but on the other hand these do not so readily penetrate it as if the tubes were open. When the collapse is more extensive, the contrast in the flatness on percussion and indistinctness of the respiratory murmur on the affected side, and the marked resonance and loud murmur on the other, may serve to identify the affection. In extensive, traumatic cases this contrast is much more prominently marked, as the expanded portions have to take on extra compensatory work and are not infrequently rendered emphysematous. The drum-like sound in percussion of such parts, and in the upper part of the chest in pneumothorax are pathognomonic of these conditions. Again in hydrothorax the horizontal upper level of the area of dulness betrays a liquid cause. Severe cases are marked by cyanosis.

The lesions seen in atelectasis consist in depressed areas of a dark fleshy color on the surface of the lung, usually sharply limited by the borders of the lobules, and in strong contrast with the bulging, light colored lobules adjacent, which are often emphysematous. The collapsed lobule may usually be dilated when air is forced into the bronchium, but if it has been of some standing this is often difficult or impossible. If it has resulted from bronchitis or compression of a previously inflated lung it will often float in (not on) water, from a little retained air, but in congenital atelectasis it is airless and sinks to the bottom.

When treatment is demanded it will vary according to the cause. In congenital atelectasis the respiratory centres must be roused. The new born animal may be sprinkled alternately with ice cold and hot water, or the chest may be slapped with the palm of the hand or a wet towel. The nostrils must be cleared of mucus, and the lungs inflated by blowing or bellows, the larynx being pressed back against the gullet to prevent inflation of the stomach. If available electricity may be applied to the chest walls. These measures may be repeated at intervals and the systemic weakness overcome by nourishing food, stimulants and friction of the skin.

In acquired atelectasis we should seek to correct the disease to which it owes its existence. In bronchitis the measures already indicated for the liquefaction and removal of the expectoration will be in order; in hydrothorax a judicious paracentesis and in pneumothorax the aspiration of the gas, and the closure of any traumatic opening through which that gas has gained access.

HÆMOPTYSIS.

Causes, over-exertion in plethoric, glanders, pulmonary tubercle, petechial fever, embolism, aneurism, ulcerated new formations, anthrax, septicæmia, hæmorrhagic diathesis. Symptoms. Inappetence, cough, cold limbs, rigor, hard pulse, jugular pulse, violent heart beats, unsteady gait. Discharge, bloody, crimson, frothy, with cough, without acid, excited breathing, debility. Indications from pre-existing disease. Treatment, quiet, elevated head, cold irrigation, ice bags, acetate of lead, opium, ergot, matico, tannin, iron, oil of turpentine, laxatives, cool stable.

The term hæmoptysis (αιμα, blood, πτυω, I spit,) is now entirely restricted to bleeding from the lungs and lower air passages. It is a very rare complaint in the lower animals, but is sometimes seen in both horse and ox. In very plethoric subjects the overloaded circulatory organs give way in the delicate membrane, lining the ultimate bronchial tubes and the air cells. The exciting cause in such cases is usually some severe effort of draught, a violent gallop, or other unwonted exertion. It occurs in glanders from rupture of caseated pulmonary nodules. It does not appear to be so common in phthisis in the lower animals as in man, but one case occurred under the eye of the writer in which the bursting of a large tubercle in the lung of a cow involved the rupture of a considerable vessel with a fatal result. Pulmonary embolism and infarction, petechial fever, aneurism, ulcerated neoplasms, anthrax, and septicæmia are additional causes. Lastly hæmoptysis sometimes takes place in hæmorrhagic subjects without any appreciable rupture of vessels, the blood sweating from the surface of the bronchial mucous membrane.

Premonitory symptoms are sometimes noticed, such as dulness, and lassitude, loss of appetite, a frequent short cough, coldness of the limbs and surface, shivering, full, hard pulse, pulsation in the jugulars, tumultuous action of the heart, and unsteadiness of gait.

More commonly it comes on suddenly as the result of severe muscular strain or excitement. The blood flows from the nose, and rarely from the mouth in solipedes, but indiscriminately from both in other animals. It is bright red, clear, frothy, or mixed with mucus, and variable in amount. It is easily distinguished from nasal hæmorrhage, which is not frothy, and from bleeding from the stomach, which is clotted and blackened, with an acid odor from the presence of the gastric juice. The cough of hæmoptysis contrasts with the sneezing of epistaxis and the retching of hæmatemsis. The rattling cough increases the discharge, as does also a dependent position of the head. Besides the cough there is usually an anxious countenance, accelerated breathing and considerable lifting of the flank. When the loss is excessive there is weakness, giddiness, rolling of the eyes, and pallor of the visible mucous membranes.

The previous ill-health of the patient, the presence of tubercle as ascertained by auscultation and percussion, and the hæmorrhagic constitution as shown by occurrence of bleeding from other parts of the system will lessen the chances of a favorable termination. Sometimes, too, the flow is so profuse that the blood cannot be coughed up, and filling the bronchial tubes it destroys life suddenly by suffocation.

Treatment. When brought on by severe exertion absolute quiescence will usually check hæmoptysis. Keeping the head in an elevated position favors its arrest. The application of cold water to the head, neck and thorax, and the giving of iced water, strongly acidulated by vinegar or one of the mineral acids may sometimes be required. In threatening or obstinate cases one drachm of acetate of lead may be given thrice daily to check by its astringent effect on the vessels, and the addition of a drachm of opium is of great value in suppressing the cough. Ergot, tannin, matico, and oil of turpentine have each been employed with advantage, and when costiveness exists a saline laxative (one pound sulphate of soda) may be usefully resorted to. The patient should be kept in a cool, airy dwelling, and should rest for fifteen or twenty days after an attack.