530 



pm^ASES OF THE SKm, 



a genuine analogy with facial and genital herpes of man. But the 

 word herpes has been so much used aud abused in veterinary medi- 

 cine that it is impossible to gain any light concerning the nature of 

 a large number of observations described under this appellation. 

 As already proposed by Gerlach, it ought to be reserved to desig- 

 nate herpes tonsurans. 



The benign exanthema which has just been mentioned has noth- 

 ing in common with herpes zoster (zona), which is developed along 

 the cutaneous nerves. 



SHBDDINa OF HAIR AND WOOL. 

 Alopecia. 



Shedding of hair or wool, occurring independently of any disease 

 of the integument, may be observed upon the whole body or be 

 limited to circumscribed regions. It is generally considered as the 

 consequence of certain nutritive troubles of the skin (tropho-neu- 

 roses), which are accompanied by atrophy of the hair bulbs, but we 

 could not affirm without reserve that it is not of a parasitic nature, 

 although up to the present time no micro-organism could be seriously 

 incriminated. 



Etiology. The causes of alopecia are imperfectly known. A 

 general falling out of the hair is always under the influence of a 

 serious alteration of nutrition ; it is also designated under the name 

 symptomatic alopecia. It may appear in cachectic conditions dur- 

 ing gestation (Koller),^ in the course of chronic diseases, of some 

 affection of the blood (petechial fever), under the influence of abun- 

 dant lactation, prolonged sudations (Hertwig), and circulatory 

 troubles of the skin ; it is more rarely due to a spare alimentation, 

 to the ingestion of certain fodders (hay from low, swampy meadows 

 — Fomin). Finally, it is sometimes congenital (Koller).^ 



Areolated alopecia {alopecia areata, area Celsi, area Johnstoni) 

 is considered by some as a tropho-neurosis, that is to say, nutritive 

 trouble, happening in the region of the cutaneous nerve ; others 

 classify it among parasitic diseases. 



Symptoms. 1. In symptomatic alopecia the whole cutaneous 



1 Koller (communication), 



2 Generalized neurotic alopecia has been observed by Joly on an energetic and irri- 

 table horse, which had struggled hard for " une prise de longe." In a few days the 

 flkir became absolutely smooth (Presse Vét., 1889). — n. d. t. \ 



