SECTION V. 



DISEASES OF THE SKIN. 



GENERAL CONSIDERATIONS. 



Diseases of the external integument are not observed with the 

 same frequency in all our domestic animals. Particularly common 

 in the dog, horse, and sheep, they are rarer in the ox, pig, goat, cat, 

 and birds. In all these species they take the most varied forms. 

 Old authors have arbitrarily applied to them the titles of the 

 skin diseases of man, and such names as tetters (herpes), rash, rot, 

 mange, scab y thrush, grease, etc., have often served to designate 

 cutaneous diseases of a very different nature.^ These terms have 

 been perpetuated up to the present time. It would be of advan- 

 tage to abandon completely this, old nomenclature, but we would 

 not know how to make the change at present without danger of 

 being misunderstood by practitioners ; we can, however, suppress 

 part of them without any inconvenience, and refer to certain prin- 

 cipal dermatoses those accessory tegumentary lesions described 

 until now as special diseases. Following Hebra^s example, we 

 shall extend the pathological outline of eczema; as Gerlach has 

 already proposed, we shall use the term herpes in order to designate 

 diseases determined by vegetable parasites; finally, we shall reserve 

 the expression mange in order to designate diseases produced by 

 the acari. 



A rigorously scientific division of diseases of the skin is much 

 more difficult to establish in veterinary than in human medicine. 

 In our animals, in fact, their diagnosis is rendered obscure by the 

 presence of hair and pigment ; a diffuse or circumscribed redness 

 is only observed in animals having a white skin ; in others it can 

 only be recognized on certain limited regions where pigmentation 



1 French authors designate these dermatoses under the generic name of Thrush. 

 The word tetters means a benign affection which is characterized by vesicles which 

 are filled with a clear liquid and are disposed in groups. — n. d. t, 



(489) 



