288 DISEASES OF THE SKIN 



Symptoms. — ^The symptoms are those of severe itching, 

 with which is associated a squamous eczema, the skin being 

 covered with bran-hke scales which accumulate to form thick 

 crusts. If diffuse, the skin surface assumes a peculiar silvered 

 appearance "as if strewn with guano." The underlying skin 

 is thickened and creviced. If diffuse and of long duration 

 emaciation follows. It is difficult to find the mites under the 

 microscope, as they are limited in numbers. 



Treatment. — ^The skin should be thoroughly scrubbed with 

 green soap and water to soften the crusts. This may be 

 followed by the use of sulphur ointment, creolin liniment, or 

 a tar salve. 



Follicular Mange. — Occurrence. — This form of mange 

 which is common in dogs, where it assumes two forms, the 

 squamous and the pustular, is rare in other animals, with the 

 possible exception of the pig. 



Etiology. — The hair follicle mites, Demodex foUiculorum, 

 live in the sebaceous glands and hair follicles. Following 

 their invasion pus cocci enter, leading to abscess formation. 

 In swine the Demodex foUiculorum (var. suis) is the offender. 

 The region of the snout, neck, ventral portion of the chest, 

 the abdomen and inner parts of the thighs are the favorite 

 seats. In these regions pox-like pustules to hazel-nut-sized 

 boils or abscesses as large as walnuts appear. In the center 

 of an abscess hundreds of the mites may be found. 



Diagnosis. — Diagnosis depends upon finding the mites 

 under the microscope. 



Prognosis. — ^The prognosis in swine is not good, as the 

 disease is very obstinate. An operative treatment which 

 consists in removing the affected skin is recommended. 



HERPES. RINGWORM. 



Definition. — ^A contagious skin disease due to a fungus and 

 characterized by the formation of round, sharply defined 

 areas covered with scales and short, uneven hair stumps. 



Occurrence. — Ringworm is very common in cattle, especi- 

 ally during the winter season, when they, are stabled. It is 

 sometimes, therefore, known as " barn itch." While more or 



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