74 DISEASES ,OF POUtTRY. 



are found in abundance between the epithelium and 

 the mucous surface. 



There are no characteristic symptoms in addition to 

 the whitish patches upon the affected membrane. The 

 patients are depressed, the mouth exhalles an acid odor, 

 the head may be swollen, the appetite is preserved, but 

 there is rapid loss of weight and strength. Death is 

 preceded by convulsions. 



The canker of pigeons is believed by some investi - 

 gators to be caused by this fungus.. 



Treatment. — The system of the bird should be 

 strengthened by good food and tonics. The part 

 affected should be treated with antiseptics and particu - 

 larly with a ten per cent solution of borate of soda or 

 with boric acid solution fifteen grains to the ounce 

 of water. These solutions should be applied quite 

 frequently in case the affected part is in the mouth, 

 where it can be reached. When the disease is localized 

 in the lower part of the oesophagus it can ilot be diag- 

 nosed during the life of the bird and hence can not be 

 treated. 



DIPHTHERIA. 



Whitish, grayish, or yellowish patches of false mem- 

 brane are frequently seen upon the mucous membrane 

 of the mouth with various species of birds. This is 

 generally due to diphtheria, a serious, contagious dis- 

 ease described in the chapter on generalized infectious 

 diseases, to which the reader is referred. 



PSOROSPERMOSIS. 



Diphtheritic processes, pustules and ulcers of the 

 mouth in poultry and pigeons have been attributed by 

 numerous authors to psorosperms, or parasitic proto- 



