138 Enzootic Pneumonia of Young Animals. 



cliopneiiHioiiia with or without a simultaneous pleuritis or peri- 

 carditis. Individual lobules or occasionally whole lobes (espe- 

 cially the anterior and median lobes and the anterior angle of 

 the principal lobes) apjjear brown, jjurple or grayish-red, flesh- 

 like, dense, non-crepitant when cut into. The interlobular con- 

 nective tissue appears occasionally somewhat swollen; the 

 bronchi contain mucoid, gelatinous yellowish masses of secre- 

 tion. The bronchial and mediastinal glands are markedly 

 swollen. 



The chronic form presents a flabby pneumonic consolida- 

 tion. Occasionally one finds in the affected pulmonary tissue 

 purulent or caseous foci from pea to walnut size, in other cases 

 dry, grayish yellow necrotic foci, sometimes also cavities as 

 large as a fist. The pleurae present the picture of a chronic 

 fibrous adhesive inflammation. The bronchial and mediastinal 

 Ijanpli glands often show considerable chronic swelling and 

 exceptionally contain dry foci up to the size of a lentil. 



Pneumonia assumes the form of bronchopneumonia sup- 

 purativa if caused by bacillus pyogenes (Olt, Holth) or bacteria 

 of the coli group (J. Miiller). It is then characterized by a 

 light 3^ellow suppurative condition of the small bronchi, in the 

 middle of the hepatized or only atelectatic lobules. A gradual 

 purulent liquifaction of lobules, inspissation of pus and adhesive 

 pleurisy radiating from the bronchioles takes place in the 

 further course of the disease. 



Kitt described a caseous broncliopneuniouia iu a young steer which was very 

 similar to pulmonary tuberculosis, but differed from it in that there were no 

 caseous foci in the connective tissue between the white yellowish caseous looking 

 lobules; calcareous changes and cavity formation was likewise absent. The exudate 

 in the bronchi contained exclusively the bacillus bronchiolitidis vituli (see page 135), 



Symptoms. The duration of the period of incubation varies 

 a good deal according to the type and virulence of the patho- 

 genic bacteria, and it can be determined only in cases with 

 an acute course. 



According to Schreiber septic pneumonia occasionally appears on the second 

 day of life ; in other cases on the ninth to seventeenth day after infection. In 

 contagious catarrhal pneumonia of young pigs Grave observed a period of incubation 

 of ten to fourteen, rarely up to twenty-four days. 



The clinical picture itself varies a good deal. One can 

 distinguish, generally speaking, an acute and a chronic form 

 of the disease. 



The acute form is usually observed in very young animals 

 a few weeks old at the utmost; it is initiated by a decrease 

 in the lively behavior and in appetite, and by a fel)rile ele- 

 vation of temperature up to 41° to 42° C. The respiration 

 is accelerated from the start and becomes more and more fre- 

 quent, so that after a few days the number of respiratory move- 

 ments may be 40-60 even 100 per minute. At the same time 

 the respiration becomes forced, the animals spread their front 

 legs, stretch their heads and neck; calves and foals also dilate 

 their nostrils. Cough occurs soon after the onset of the dis- 



