924 Favus of Fowls. 



(b) Favus of Fowls. 



Wliilc-conih; Welsser Kamm, Hahnenkamm-Grind [German]; 



Tinea s. Favus Galli, Tinea cristce Galli; Favus de 



la poule, Crete hlanche, Maladie de la 



erete, Lophophytie [French].) 



Favus of fowls is a contagious skin disease of cliiekens 

 Avliieli chiefly affects the unfeathered portion of the integiunent 

 of the head, procUicing a moukly deposit, and which is caused 

 by a variety of the favus fungais called the Lophophyton (der- 

 matomyces) gallinarum. 



History. Fowl favus, which appears first to have become known 

 after the introduction into Europe of foreign lireeds of chickens, 

 especially Cochin China and Brahma hens, was showai to be a mycotic 

 disease nearly simultaneously by Fr. Miiller (1858), Leisering (1858), 

 and Gerlach (1859), and Avas later descri])ed in detail by Rivolta (1873) 

 and by ]\Iegnin (1881). A thorough etiological investigation of the 

 disease with transmission experiments was made bv Schiitz (1884). 

 More recently Duclaux (1890), Constantin & Sabrazes (1893), Tis- 

 chutkin (1894), as well as Matruchot & Dassonville (1899) have studied 

 the disease. 



Occurrence. Principally fowls belonging to the larger 

 Asiatic breeds are attacked b}" the disease, especially in zoologi- 

 cal gardens, somewhat less frequently indigenous breeds of 

 fowls. According to Sabouraud, Suis & Suffran, cocks are more 

 frequently affected than hens, and fowls with short beaks more 

 than others. The birds are said to fall ill at the earliest in the 

 6tli or 7th months of life after the comb and the wattles have 

 obtained a certain degree of development. Now and then 

 turkeys may be affected (Theobald). 



Etiology. The Lophophyton gallinarum Matruchot & Das- 

 sonville (Dermatoinyces s. epidermophyton s. achoxion gal- 

 linarum) is a variety of the fa\ais fungus closely related to the 

 tricophyton fungus; it forms two kinds of hj^jh?? on the skin, 

 the one are long, undulating filaments which are 2 to 5 microns 

 thick, divided into unequally long segments, free from proto- 

 plasm, and have delicate walls and often gnarled side shoots; 

 the other are short, at times have forked branches and consist 

 of ^ or 4 thick-walled cells that contain a strongly retractile pro- 

 toplasm, about 4 to 6 microns thick (by Ziirn and others consid- 

 ered to be chains of spores) and later on divide into single cells. 

 The disease is spread exclusively by the last named socalled 

 l)ermanent mycelia, while actual spores are said to be wanting 

 (Matruchot & Dassonville). 



Pure cultures of the fungus are obtained after isolation (see page 

 901 ) at room temperature, l)ut more easily at a temperature of 30° C. 



