678 



DISEASES OF THE SKIN. 



The principal indications in treatment are the softening of the 

 scabs, their removal, and injections of glycerin of cresolated or car- 

 bolated oil in the external ear (2 to 5 per cent.). 



Addendum. Mange of the Ferret. 



We observe a sarooptio and symbiotic mange on this animal.* 



FOLLICULAR MANGE. 



Follicular mange, which is frequent in the dog and cat, less fre- 

 quent in the pig (Csokor) and ox (Grimm), has sometimes been 

 observed in the sheep (Oschatz), the goat (v. Niederhausern), the 

 stag (Prietsch), even upon the bat, rat (Hahn), and field mouse 

 (Zschokke). It is produced by the Demodex folliculorum. This 

 acarus exists frequently in the comedones of man's face, (dilated 

 sebaceous glands), without producing any morbid phenomenon. 



Natural History. Demodex folliculorum was discovered in 

 1843 by Henle and Simon in the comedones of man. At the same 

 time Tulk found it upon the dog. It is a parasite of the group of 

 Arthropodes, belonging to the family of the Dermatophiles, the 

 order Acari and class Arachnides. At the present date we dis- 

 tinguish several varieties. 



Demodex folliculorum, var. canis, cati, suis (also designated under 

 the name of Demodex phylloides by Csokor), hominis, etc. 



In the adult state the Demodex folliculorum is a vermiform para- 

 site, shaped like a laurel leaf and one-third to one-quarter of a 

 milimetre in length ; it comprises three parts : the head, thorax, 

 and abdomen, the first two being joined in a single organ. The 



1 [Sarcoptic mange, which is determined by Sarcoptes scabiei, var. hydrochœri, is at 

 times localized on the head and feet, at other times it is spread over the whole body. 

 It is indicated by a gelatinous pitchy oozing, by depilations, grayish or brownish 

 scabs and an intense prurituS; When the disease is old the parasites are often accu- 

 mulated upon the ears and feet, on the base of the paws, which become deformed and 

 acquire enormous dimensions. 



Symbiotic mange (auricular acariasis) is produced by Symbiotes auricularum, var. 

 furonis. In the generality of cases its spread is so insidious that the troubles produced 

 by it pass unnoticed. We may, however see the patients scratch their ears; we re- 

 mark also an unusual weakness, depression, and torpidity, but the epileptiform 

 symptoms observed in auricular acariasis of the dog and cat are exceptional in the 

 ferret. 



As soon as the parasites exist in large numbers they produce violent inflammatory 

 phenomena, destruction of the tympanic membranes, lesions of the middle ear, cariea 

 of the internal ear, or a fatal meningo-encephalitis.] 



