FACE-MITES. 



49 



Fig. 25.— De- 

 mo d ex of the 

 dog; mites 

 shown in hair- 

 follicle. Greatlj' 

 enlarged. Orig- 

 inal. 



glands of the hair. If purposely introduced from the dog to 

 the skin of man, it causes an itching sensation, and soon 

 afterwards a sore spot and a scab. As proved by many trials 

 it is a very fortunate thing that this parasite 

 does not readily migrate to man. Fig. 25 

 shoves a number of the parasites in the hair- 

 follicle of a dog. 



Remedies. — The disease caused hy these 

 parasites upon domesticated animals is not 

 easily cured, and only in the early stages is 

 a cure possible. In this case salves or oint- 

 ments made from salicylic acid, or a mixture of 

 one part benzine to 4 to 8 parts of soft soap, 

 do good service. A strong kerosene-emulsion 

 would also, no doubt, be of great value, es- 

 pecially if an extract of pA^rethrum is added. 

 An ointment made of half a pound of lard, 2 

 ounces of tar, and 4 ounces of sulphur, rubbed 

 in before a fire or in the sun, is very effective, 

 if it is allowed to remain on the skin for some days. Peruvian 

 balsam, a salve made of corrosive sublimate (1:100), Creolin 

 (2: 100), Lysole, Styrax (1: 30 oil), a salve made of canthar- 

 ides (1:6 fat) are also recommended. Several other washes 

 are frequently used which \\411 be given later. Success de- 

 pends much more on the manner in v^hich the medicinal agents 

 are used than upon the agent itself, and the strongest ones 

 may prove perfectly useless if not properly applied. Nothing 

 short of a thorough rubbing in of the salves will suffice, and 

 this operation has to be performed many times. Of course the 

 patient should be w^ell fed, as even after the death of the par- 

 asites the skin is for a long time in an inflamed condition. 

 Cleanliness is here also the best preventive, and the diseased 

 animal must be isolated and its old sleeping place should be 

 thoroughly disinfected. 



There is still another species of Demodex, similar to the 

 one infesting the dog, that has repeatedly been more or less 

 injurious to cattle. Mr. W. Faxon first called attention to 

 the diseased condition of cow-hides received in Boston from 



