Pneumonia In Dogs Research Articles

THE RELATIONSHIP OF INFECTING DOSAGE, LEUCOCYTIC RESPONSE, BACTEREMIA, AND EXTENT OF PULMONARY INVOLVEMENT TO THE OUTCOME OF EXPERIMENTAL LOBAR PNEUMONIA IN THE DOG

The present study comprises observations on the course and outcome of experimentally produced Type I pneumococcus lobar pneumonia in dogs. It was found that within certain limits of dosage the outcome of the disease was closely related to the amount of culture and the volume of the starch inoculum employed. The much higher mortality rate resulting from simply increasing the volume of starch in which the pneumococci were suspended, appeared to be due chiefly to the greater area of lung tissue initially involved. Certain striking relationships were observed to exist between the leucocytic response, extent of pulmonary involvement, bacteremia and outcome. Marked changes in the number of white blood cells at end of the first 24 hours of the disease provided more valuable prognostic information than either the blood culture or the size of the lesion. Dogs showing high white counts at this stage seldom succumbed, while absence of leucocytosis and leucopenia were associated with a mortality which increased with the diminishing numbers of circulating white blood cells. Over 90 per cent of the animals with counts of less than 2,000 cells per c. mm. died. The extent of the pulmonary lesion was likewise observed to bear a direct relationship to death rate. With the lesion confined to a single lobe the mortality was only 1 per cent. Spread to other lobes was accompanied by a sharply rising death rate until it reached 98 per cent in dogs with three-fourths the lung field involved. Increasing occurrence of bacteremia paralleled both the decreasing white counts and the extending pulmonary lesions and subsequent to the 24 hour stage of the disease the presence or absence of pneumococci in the blood appears to be of more significance, in relation to outcome, than either of these two other factors. Even in the presence of leucopenia and an extensive lesion the animal might survive provided the blood remained sterile.

THE METABOLISM OF LUNG TISSUE IN EXPERIMENTAL LOBAR PNEUMOCOCCUS PNEUMONIA IN THE DOG

The metabolism of infected and uninfected lung tissues was determined at various stages of experimental lobar pneumococcus pneumonia in dogs. Analyses of tissues and analyses of the blood entering and leaving the lungs indicate a fairly normal aerobic metabolism of the tissue throughout the course of the infection.

Visceral Displacement in Pneumonia

Introduction MEDIASTINAL displacement and diaphragmatic elevation are commonplace findings in massive atelectasis and in certain phases of pulmonary tuberculosis, and physicians are beginning to realize that they may occur also in lobar pneumonia. Van Allen and I (1) have reported several instances in experimental dogs. Thoenes (2) reported 11 cases of pneumonia, all showing displacement of the heart to the affected side. Wallgren (3) stated that he had frequently observed, in the pneumonias of young children, displacement of the heart to the affected side. St. Engel (4) considered elevation of the diaphragm on the affected side a common occurrence in lobar pneumonia. Griffith (5) reported displacement of the heart to the affected side in 16 out of 40 cases of lobar pneumonia in very young children. Coryllos and Birn-baum (6) reported mediastinal and diaphragmatic displacement toward the affected side in experimental pneumonia in dogs and stated that they frequently found the heart and trachea similarly d...

LOBAR PNEUMONIA

In a preliminary paper we have given the results of our experimental investigations on lobar pneumonia in dogs, briefly stating the experimental facts on which we have based the theory that lobar pneumonia must be considered as the pneumococcic variety in the large category of obstructive atelectasis of the lung. In the present paper, we propose to develop this theory further and to show that a new light may be thrown on our knowledge concerning lobar pneumonia which may help to explain in a simple and clear way a great number of its features that have heretofore been inexplicable; furthermore, we shall show that pneumonia, up to now considered an exclusively medical disease, may be as much surgical as medical, and as such require an emergency treatment, necessitating a closer collaboration of the thoracic surgeon, the internist and the bronchoscopist. We shall first develop our conception of lobar pneumonia and

ON THE MECHANISM OF CHLORIN RETENTION IN PNEUMONIA

THE FOLLOWING CONCLUSIONS MAY BE DRAWN FROM AN ANALYSIS OF THE PROTOCOLS: 1. The chlorin output is very much diminished during the process of experimental pneumonia in dogs (tables I and II). The quantity of chlorin retained in the cases with well developed exudates (table I) is much larger than the exudate could account for. 2. Turpentine pleurisy in dogs (tables III and IV) also is associated with a retention of chlorin, but this is not so marked as in pneumonia. There is no direct quantitative relation between the water output and the chlorin excretion. 3. The rabbits with pneumococcal septicemia (tables V and VI) did not retain chlorin in any phase of the disease, a fact which Hutchison has also noticed. It seems justifiable to conclude that the retention of chlorin in the organism in the course of pneumonia is conditioned by more than one factor. The formation of the exudate is one of these factors, but it alone is not capable of producing the same degree of chlorin retention as occurs in pneumonia. The additional factors are not yet determined; but it may be stated that the retention of chlorin is probably not due to the general effect of the pneumococcus on the organism or to its injury to the kidney. The principal cause of the retention seems, therefore, to be due to local changes associated with the pulmonary condition.