482 PARASITIC SKIN DISEASES 



alcohol (1.0-5.0) has given good results but the odor is objec- 

 tionable in house pets. Animals being treated with oily or 

 fatty preparations must be kept in a warm place as the heat 

 radiation from the body is increased by such application. 



DERMATOMYCOSIS. 



Vegetable Parasitic Disease of the Skin. 



Definition. A communicable disease of the skin produced 

 by fungi, somewhat similar to ordinary molds. Several 

 species of fungi have been found to produce skin diseases. 

 From the standpoint of clinical diagnosis they may be divided 

 into two classes. Identification is possible only by their 

 cultural characteristics. These parasites occur on the skin 

 in the form of mycelia or filaments which may or may not 

 be segmented. From these segments spores are formed which 

 in turn, germinate to form new mycelia. The spores are 

 round or oblong and under the microscope strongly refract 

 the light. 



Examination. The mycelia and spores are extremely 

 small and require high power magnification. A smear slide 

 made with scrapings from the crusts or scabs, examined under 

 high power, will show them as small, rounded spores either 

 scattered or in chains. The segmented mycelia may also be 

 recognized. It is advisable to pull a few hairs from the dis- 

 eased area and examine near the roots for masses of fungi. 



HERPES TONSURANS. 



Ringworm. Red Itch. 



Etiology. This disease is produced by the Trichophyton 

 tonsurans or other similar forms of fungi which are usually 

 classed as the trichophyta. 



Pathology. The fungi develop around the shaft of the 

 hair and extend down into the follicle but not to the root. 

 The hair becomes brittle, splits and breaks off close to the 

 skin. The enormous number of spores that grow in the 

 follicles and beneath the epidermis set up inflammation, 

 especially in the parts of the skin thickly covered with hair. 



