DEPILATING THRUSH. 539 



scab falls off we find in its place a blotch, the epidermis of which is 

 slightly desquamated, and where the hairs grow again gradually. 

 The duration of the disease varies from six to twelve weeks. In 

 cases where its normal course is interfered with by mechanical in- 

 fluences (scratching, rubbing, etc.), it spreads by a series of inocu- 

 lations; new blotches are developed in the neighborhood of the 

 healed regions, and it may last for many months, even for years. 



In suckling calves it is mainly located in the neighborhood of 

 the mouth (mouth thrush). It has also been observed in the same 

 location upon other sucking animals (lambs, kids, young pigs). 

 Some authors have described an impetiginous eczema which is non- 

 parasitic and limited to the buccal mucous membrane. But the 

 clinical picture and the striking contagious character of this disease 

 indicate that in the majority of cases depilating thrush is indicated, 

 an opinion which has been elsewhere confirmed by the microscopic 

 researches of Hahn,^ who found the trichophyton in the buccal 

 lesions. According to this author, the trouble is mainly character- 

 ized by the presence upon the surface of the mucous membrane on 

 the edge of the lips, and at times over the whole surface of the 

 body, of spots which become covered with dry, furfuraceous scabs; 

 on those which are developed upon the skin we observe the hair 

 slit and broken by the fungi. It is very obstinate in young 

 animals. 



2. In the dog. As a rule, it is located on the head and ex- 

 tremities ; at times it extends over the entire surface of the body. 

 It starts with round, isolated, distinctly circumscribed spots ; later 

 we may find upon the whole skin bare island-like spots, which are 

 of circular or elliptic form, and from one to two centimetres in 

 diameter ; they are particularly numerous in the neighborhood of 

 the lips, eyes, and extremities. In some cases these islands unite 

 into large blotches, the objective character of which varies accord- 

 ing to the location and length of the process ; we find quite often 

 the alterations of plain non-inflammatory alopecia in it {area Celsi) ; 

 frequently also the skin is covered with scabs, sometimes thin, of 

 an amianthous or dirty gray color, at other times this is thicker, 

 agglutinating the hairs at the base ; when detached, the integument 

 appears copper -red or red-brown colored and strewn with a large 

 number of small pimples of the size of a millet-seed (compressed 

 tumefied follicles). Sometimes the diseased parts are quite promi- 



1 H'ahn: Miinchen. Jahresber., 1861. 



