Symptoms. 



921 



lying beneath the little shield causes a trough-shaped depression 

 to be formed. 



On parts of the skiu in man which are not covered with hair the development 

 of favus shields is preceded by a process similar to that of herpes tonsurans 

 vesiculosus (favus herpeticus, early herpetic stage of favus). Formerly a similar 

 form of favus, arising from a natural infection, was attributed by Quincke to a 

 special favus fungus (frequently called achorion Quinckeanum) which he claimed 

 to produce honeycomb ringworm in cats and mice. 



Symptoms. In cats and dogs the paws, especially around 

 the claws, the scalp, and in cats especially the external ear are 

 the favorite localizations of the disease, that is, those parts of 

 the body which are most exposed to infection while the cats plav 

 with the mice they have caught ; but favus may occur on other 



Fig. 



136. Favus scutellum on the outer surface of the external 

 (after Schindelka). 



ir of a cat 



parts of the body, not rarely in the region of the umbilicus, at 

 the lower chest and on the inner surface of the legs. 



Accompanied by a slight or without any itching, small 

 round and yellow or grayish white spots develop here and there 

 over the skin above which they slightly protrude. Gradually 

 increasing in size to that of a one-cent piece, they be- 

 come rough and concentrically cracked on the surface ; the mar- 

 gins are raised, giving the lesions their characteristic saucer 

 or cup-shaped depression. The fungous shields or favus cups 

 (Fig. 136), which are formed in this manner, are yellowish or 

 silver gray on the outside, but always sulphur-yellow in their 

 interior (especially after moistening with alcohol) ; they may be- 



