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.