40 DISEASES OF THE TRACHEA 



In treating a large number of birds encourage the appetite 

 with stomachic tonics (iron sulphate) in the food and drink- 

 ing water. 



MYCOTIC PNEUMONIA. 



Aspergillosis. 



Definition.— A mycotic disease affecting primarily the 

 respiratory passages, often producing bronchitis and pneu- 

 monia. 



Etiology.— The exciting causes are species of fungi belonging 

 to the genus Aspergillus. These fungi exist abundantly in 

 nature upon all kinds of grain especially during the warm, 

 moist weather. The spores are inhaled with dust or taken 

 with food and lodge on the mucous membrane where they 

 rapidly develop into the fungus, which causes the irritation. 

 The most common species in the domestic birds are the 

 Aspergillus fumigatus, A. nigrescens, A. glaucus and the 

 A. candidus. 



Other species are rarely found in the respiratory tract of 

 birds. The predisposing factors are bronchitis, affections 

 of the lungs, delicate breeds of birds, or delicate and weak 

 individuals. 



Pathology. — (a) On the mucous membrane of the trachea 

 and bronchi is found a thick membranous mass which bears 

 upon its surface a growth of the fungus. These masses are 

 at first soft but become firmer with age and are yellowish or 

 greenish in color, with some resemblance to a fibrinopurulent 

 exudate. They adhere firmly to the mucous membrane 

 which is thickened and congested. These growths may 

 obstruct the air cells and the smaller bronchi, often being 

 found as caseous or even calcareous nodules, somewhat 

 resembling tuberculosis. The nodules vary in size from 

 that of a pinhead to a pea and may involve the greater part 

 of the lung tissue. Nodules may also be found in the liver, 

 intestines, the mesenteric glands or other organs. In very 

 acute cases the lungs may show simply an acute inflammation 

 with secondary conditions in other organs. 



