510 



DISEASES OF THE SKIN. 



The duration of the process is often very long. It is always- 

 difficult to obtain a cure. 



Treatment. It consists in cleansing the diseased regions thor- 

 oughly and in drying the moist blotches. Before all else it is 

 indispensable to cut the agglutinated horse-hairs at their root. 

 After having rendered the skin accessible to medicament, we apply 

 upon it a liniment of creosol or tar or astringent drying powders 

 (iodoform mixed with powdered oak-bark), or a solution of nitrate 

 of silver, 6 per cent. The latter produces a blackish coloration of 

 the hair on light coats, a circumstance which should be mentioned 

 to the owner. In most cases the trouble necessitates long treatment. 



We have considered plica or Polish plica as a phenomenon of 

 wet chronic impetiginous eczema of the upper border of the neck 

 and shoulders, an affection in which the propagation of the inflam- 

 mation to the hair follicles may determine an alteration of the 

 horse-hair. The descriptions which were formerly applied to plica 

 in the treatises upon veterinary pathology, and the importance 

 which the public has for a long time attributed to it, occasion some 

 astonishment. It was formerly considered as an enzootic disease. 

 It had also been regarded as a favorable premonitory manifestation : 

 its appearance during the course of an internal disease announced its 

 near cure ; its disappearance, on the contrary, predicted a fatal 

 termination. 



Some authors, Spinola among them, admit that plica depends 

 upon a constitutional disease ; Haubuer classifies it aïnong nutri- 

 tive troubles; others maintain that it is determined by fungi. 

 Haselbach has observed it quite recently on one- tenth of the 

 equine population of Polaud. He considers it an affection of the 

 mane and tail in which a viscous liquid is excreted from the stem 

 of the hair ! Strange opinions formerly advanced as to its nature 

 are rendered still more confusing by the distinction of true and 

 false plica. The latter term has served to designate a simple 

 packing of the hair of the mane and tail by dirt, dust, or other 

 foreign bodies (thistle-heads, etc.). 



In the horse, plica is a disease which is entirely due to neglect. 

 This opinion has been admitted for a long time in human medicine^ 

 where the disease is considered, besides, as an entanglement of the 

 hair due exclusively to the lack of care and to uncleanliuess. 



[I have frequently seen this disease under conditions where it 

 was not possible to attribute it to uncleanness or neglect. I have 



