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DISEASES OF THE SKIN. 



III. SKIN DISEASES CAUSED BY ANIMAL 

 PARASITES. 



A. MANGE OP DOMESTIC MAMMIPBROUS ANIMALS. 



Mange (scabies) is a contagious cutaneous disease produced by 

 acari. Without acari there is no mange. The word mange was 

 used formerly to designate non-parasitic affections of the skin — an 

 inanition mange, an adipous mange, etc., whilst true psora (itch) 

 was attributed to a dyscrasia of the blood. 



The psoroptic acari comprise the three species, Sarcoptes, Derma- 

 tokoptes (Psor optes), and Dermatophagoides {Symhiotes). The Dem- 

 odex (Acari folliculorum), which produce follicular mange, are not 

 generally considered as forming a part of the group of psoroptic 

 acari. 



These parasites give rise to so many separate dermatoses in our 

 domestic animals — each animal species has its acari — that the ex- 

 pression mange must necessarily be incomplete unless the species 

 and variety of the parasite be indicated. Sarcoptic, psoroptic, and 

 symbiotic manges are consequently distinguished. 



Mauge is frequent in the sheep and dog ; it is quite common in 

 the horse, but rare in the ox, cat, and pig. It is considered as 

 very contagious, and is classified among the epizootic diseases. We 

 have preferred to describe it in the section on Diseases of the 

 Skin, for in a work like this the practical side should predominate. 

 Certain manges, indeed, such as those of the ear or feet, are without 

 any importance from a sanitary standpoint, and do not present any 

 clinical interest. 



History. Mange in man and in animals has been mentioned 

 from the most remote ages, Moses having already considered mange 

 of animals as a special affection. Acari have also been known for 

 many centuries. According to Gerlach, the Arabian doctor Aven- 

 2oar was the first to point them out, in 1174 ; Furstenberg says 

 that they are described under the name of suren in Hildegarde's 

 Physica (1200). Wedell found acari in the cat in 1672, Kersting 

 in the horse in 1789, Walz in the sheep in 1809, Gohier in the ox 

 and the dog in 1812, Spinola in the pig in 1846. Numerous works 

 have been published on these parasites. From an entomological 

 and clinical standpoint those of Gerlach and Furstenberg have 



