An inflammation of the substance of the lungs, or pneumonia is characterized by an exudation into the air cells, solidifying for a time that portion of the lung affected. The first appreciable anatomical change in this disease is an abnormal accumulation of blood, due to an active congestion of the parts involved. This condition lasts but for a short time, and is speedily followed by an exudation, a material which escapes from the blood and coagulates within the air-cells. The cells are filled and distended with this exuded matter and cease to contain air. The lung is solidified, presenting an appearance not unlike liver, and hence this condition is called hepatization.

If the progress of the disease be favorable, the exudation is removed mainly or exclusively by absorption, and the recovery of the affected part is complete. If the disease progresses unfavorably, absorption of the product within the air cells does not take place, the substance of the lung softens and breaks down, a condition called purulent infiltration.

The constitutional symptoms then become more marked, the distress more apparent. The expression grows even more piteous and haggard, the eyes more sunken. The nostrils dilate, the cough loose, becomes persistent and distressing, and the mouth and lips are covered with a thick slime. The breath which has a sweet, sickish odor, comes quick and short. Approaching suffocation is obvious. The sitting position so long maintained is still persevered in, until the limbs become dropsical, the skin cold and clammy, the pulse faint and flickering, finally death ends all.

Causation

While exposure to cold, is an evident cause of pneumonia in many cases, it is probably but an exciting influence co-operating with an existing morbid condition or predisposition, which we are unable to comprehend. The disease is in many cases developed spontaneously, no obvious cause apparent.

Symptoms

The invasion of the disease is often abrupt. In a large proportion of cases pneumonia is ushered in with a chill, as shown by shiverings. Speedily following the chill pain is manifest, in some oases severe, in others very slight. Cough usually appears soon after the attack commences. It may be prominent, and is sometimes wanting. The matter coughed up is at first scanty and thick. In a certain proportion of cases it soon assumes a character distinctive of the disease termed rusty, from its reddish tint like iron rust.

Fever follows immediately the invasion of the disease. The pulse runs high, loss of appetite occurs, great thirst is experienced, and prostration manifested. The nose becomes hot and dry, the eyes reddened. The respirations increase in frequency, as the disease progresses, until a sense ot suffocation forces the animals to assume a sitting position, with extended bead and protruded tongue.

Diagnosis

During the early stage, by placing the ear to the affected side, crepitation can be heard in most cases. This when present is highly distinctive of pneumonia. The crepitant sound is dry, very line, crackling, and heard only on inspiration. This sound is due to the separation or bursting of agglutinlzed bubbles, and is much the same as one hears made by the boot when walking on crusted snow.

In the second stage, after the lung has become solidified, percussion shows marked dulness, a flat dead sound being emitted. The respiratory sound becomes exaggerated by the law of transmission of sound by solids, and the bronchial respiration is distinctly heard. Crepitation may be present in this stage, and may be wanting.

When recovery from the disease commences, the respiratory sound grows more natural, crepitation at times returns, and frequently a sub-oropltant sound is heard. This is fine, moist, and bubbling, carrying the idea of small bubbles, heard with either inspiration or expiration, or with both acts.

Dulness on percussion, becomes less and less marked, and finally disappears, but a trace is often left for a time after an examination by the ear shows the exudation to have been removed. If the disease does not clear up, but passes into the stage of infiltration, the dulness or flatness on percussion continues, and coarse bubbling sounds are detected, due to the presence of pus in the alr-cells, heard at times louder just after coughing, and can often be appreciated by placing the flat of the hand to the chest, when a sensation of fine bubbling will be transmitted.

Prognosis

Pneumonia is a very serious disease, and is very often fatal. At times only a small proportion of the lung is affected, the disease then being termed circumscribed. The extent of the disease in a great measure lndlcates the gravity and danger. Accidents and complications are very liable to invest the oases with greater gravity, and where there are no symptoms which denote imminent danger, sudden changes often take place for the worse.

When convalescence in the disease sets in, recovery is generally complete. From purulent infiltration there is very little hope of recovery.

Treatment

Pneumonia belongs among those diseases distinguished as self limited. If uncomplicated and not attended with accidents, it runs a definite course, ending in restoration, provided the powers are maintained. The treatment must be supportive and every influence calculated to depress the system,must be studiously avoided.

In the first stage, the object should be to relieve symptoms, to diminish the intensity of the inflammation, and prepare the system to bear the severe strain forced upon it. Many authors advise the use of blisters, but this the writer cannot endorse, considering their employment injudicious. Other authorities recommend flaxseed meal poultices, and warm fomentations. These are objectionable from the tact that the animals is liable to become chilled while the applications are being removed and changed. The object is to prevent the air coming in contact with the chest, and no better means can be devised than the cotton jacket. Many thicknesses of cotton batting can be quilted on to cloth, cut with holes for the fore legs, and roughly shaped to envelop the chest from the neck to the loins. This when basted on to the animal is a sure protection, and contributes to his comfort, by keeping the skin moistened with perspiration, and all the advantages of a poultice are thereby secured.

Opium should be given in the first stage to subdue the pain and to quiet the system. If the pulse is full and bounding and the animals in good health previous to the attack, sedatives may be combined with the opiate, and the morphine and aconite prescription recommended in acute pleurisy be used. If pain is not severe, and fever runs high, the tincture of aconite root may be given every two hours, alone, or in the following mixture -

℞ Tr. Opii Camphoratae ℥ i Tr. Aconiti Rad. gtt.xxv.

Potass. Chloratis ℥ ij.

Ammon. Muriatis ℥ i.

Syr. Simplicis ℥ i.

Aquaae ad. ℥ iij.

Ft. Mist. Shake well. Sig. Dose one teaspoonful from four to six hours.

A room of equitable temperature should be chosen, and good ventilation be maintained. Never wait in pneumonia until trouble comes; rather anticipate it, and be prepared for emergencies. Commence early with supportive measures, and insist upon it the animal takes nourishment at regular intervals. Select the concentrated and most sustaining nutriment such as raw eggs, beef juice, and beef extracts.

To support and sustain the vital powers and to prolong life beyond the limit of the disease, is the general indication in the second stage. Opium if indicated may still be persisted in, and stimulants and stimulating tonics should be commenced. Given moderately at first, but pushed if the need becomes manifest. Quinine in two grain doses should be given every four hours, and two teaspoonfuls of brandy may be administered in milk at intervals, and the effects watched. Should the pulse weaken, the stimulant must be increased to a tablespoonful dose, and given every two or three hours. If failure of the powers seems imminent, one teaspoonful of the aromatic spirit of ammonia must be added to each dose of brandy.

If the limit of the disease is reached, and resolution commenced, recovery promises to be rapid, and there is little or no danger of a renewed attack. In the stage of resolution, tonic remedies are indicated, the quinine can be discontinued, and some combination of iron be substituted. The elixir calisaya bark, iron and strychnine, in teaspoonful doses before feed-ing, is an admirable tonic. It is sometimes difficult to secure a reliable preparation however, in which event the following mixture will be found useful -

℞ Ferri et Ammoniae Cit. ℥ iss. Tr. Nucis Vomicae ℥ ij.

Tr. Cinchonas Comp. ℥ iv.

Ft. Mist. Sig. Dose one teaspoonful three times daily before feeding.

Cod liver oil should be added to the treatment, and given in tablespoonful doses after eating or mixed with the food. As soon as the animal is fairly convalescent a solid diet may be allowed, meat raw or cooked as he seems to prefer, in fact anything within reason that he will eat, and the quantity need not be much restricted. Exercise in the open air in pleasant weather should be early encouraged.

In event the lung breaks down, and the disease passes into the stage of purulent infiltration, there is little or no hope for the animal. The only treatment is to crowd the stimulants and nourishment.

Recent authorities have advised the use of chloral hydrate, to combat the pain in pneumonia. The writer feels that there are decided objections to its use, from its peculiar depressing action on the heart, which organ throughout the disease needs to be stimulated and strengthened.