GEELACH ON THE ITCH AND MANGE. 167 



form of mange observed in the horse, but which has no true 

 character to distinguish it from the human itch. 



2ndly, The horse mange in man disappears spontaneously, 

 the eruptions diminishing progressively in intensity; some- 

 times it continues so long that treatment is found necessary. 



Srdly, The predisposition for this disease is very different 

 in different persons. Some men recover from it in the course 

 of a fortnight or three weeks, others in from six to eight 

 weeks, and, in a few, treatment is required to cause the dis- 

 appearance of symptoms within this time. A soft and very 

 hairy skin is the most favourable to the spread and long con- 

 tinuance of the horse mange on man. 



4>thly, The transmission occurs through several insects of 

 )th sexes, or pregnant females. Persons suffer that attend 



mangy horses, even when these are not much affected. 



dthly, The treatment is similar to that for itch, only not 



severe. 



This form of horse mange is transmissible to cattle. Fur- 

 ler observations are called for to prove its communication 

 to the dog, cat, and pig. Gerlach has not succeeded in in- 

 ducing the disorder in sheep, by placing the sarcoptes equi 

 on these animals. 



Contagion in the horse is not so ready as might be sup- 

 posed, and a healthy horse may stand for weeks near a mangy 

 one without suffering. This depends on the state of the 

 system, and individual peculiarities. 



Scabies equi dermatodectica is that form of mange which 

 we are most conversant with, as connected with the existence 

 of an acarus known to veterinarians since the days of Gohier, 

 and which is the acarus alluded to by Kersting, Hertwig, 

 Hering, Erasmus Wilson, and others. We are all acquainted 

 with the irritation, denudation of hair, and development of 

 scurf which indicate the presence of this parasite, so readily 



