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.