138 CANINE MEDICINE AND SURGERY 



the affected parts well covered. Keep evacuated all 

 pustules that form, but use no further baths or 

 antiseptic washes. If the treatment is successful 

 and pustule formation ceases, the remaining der- 

 matitis can be relieved by inunction of Lassar's 

 paste,* or of a paste composed of : 



Ac. salicylic 2 parts 



Amylum 24 parts 



Zinc oxid 24 parts 



Petrolatum alba 50 parts 



Ringworm and Favus 



Both of these ailments are caused by vegetable 

 parasites of the genus hypomycetes or fungi. 



Favus is caused by the Achorion schonleinii, 

 which, by attacking the skin and hair, causes de- 

 struction of the latter and the formation of cup- 

 like depressions and scab formation in the former. 

 These scabs (scutula) are of a roundish shape, con- 

 cave in the center, and of a yellowish color. When 

 removed they leave a depression in the skin which 

 is thin and discolored with blood. The hair in the 

 affected portion of the skin falls out, leaving bare 

 spots, and the irritation is considerable. 



Ringworm is caused by another fungus — the Tri- 

 chophyton tonsurans — which invades the hair with 

 its mycelium, the spores as a rule being clunjped 

 round outside the hair. This invasion of the hair 

 and its root produces inflammation of the follicles 

 and renders the hair brittle, so that it breaks off. 

 The clinical symptoms of ringworm are varying 

 irritation, circular bald patches on the skin, slightly 

 elevated at their circumferences and covered with 

 dry, grayish-colored scabs. Upon close examina- 

 tion a few stumps of hairs which have broken off 

 are observed in these bald patches. If an affected 



*Lassar's paste consists of vaaelin six ounces; zinc oxide and 

 starcli of each six drams and salicylic acid thirty grains. 



