EXTERNAL PARASITES 57 



as whitish or light-gray, small, roundish patches, 

 which vary from the size of a millet seed to a 

 half-inch in diameter. Later these patches may 

 coalesce and form large areas. 



The diseased area is, covered with a scale which 

 may be depressed in the center and turned up at 

 the edges, giving it a cup-like shape. In the 

 course of four to six weeks the crusts may be 

 one-fourth inch in thickness. 



The feathers become dry, erect, brittle and 

 break off at the surface, leaving large denuded 

 areas'. A disagreeable odor is given off by the 

 diseased areas which has been likened to that of 

 mouldy cheese. As the disease progresses the 

 bird loses its appetite, becomes gradually ema- 

 ciated, weakens and finally dies. 



Treatment. — In the early stage this disease 

 yields to treatment readily. The crusts should be 

 soaked with soapy water containing a five per 

 cent solution of creolin, liquor cresolis, kreso dip, 

 carbolic acid, or similar antiseptic. The fluid 

 should find its way to every part affected. The 

 premises should be disinfected as for lice or other 

 parasites. 



Pneumomycosis— Aspergillosis 



The third fungus disease affecting birds is usu- 

 ally due to the Aspergillus fumigatus, an organ- 

 ism similar to the common green molds. It 

 affects the lungs and is discussed under "Diseases 

 of the Organs of Eespiration. " (See page 145.) 



