THE SKIN 157 



swine that have been kept in one lot. The finding of the 

 parasite is positive evidence upon which to base a diag- 

 nosis. 



Treatment. Sarcoptic mange may be successfully 

 treated by the use of the lime and sulphur dip or nicotine 

 dip, repeating every ten days for three dippings, 

 provided that the quarters are cleaned and disinfected 

 and the thick scabs are removed so that the dipping solu- 

 tion may gain access to the parasites. Some old chronic 

 cases do not respond readily, if at all, to treatment because 

 of the thick, wrinkled skin which protects the parasite. 



Demodectic Mange 



Demodectic or red mange is not so prevalent in swine 

 in America as is sarcoptic mange. Red mange rarely 

 occurs enzootically. 



The cause of red mange is the Demodex folliculorum, 

 var. suis. This parasite is not visible to the unaided eye. 

 Microscopically, it is found to be similar in shape to an 

 oat grain and has four pairs of short legs. The life cycle 

 of this parasite is practically the same as of the Sarcoptes 

 scarbiei, var. suis, except that the ova are deposited in a 

 pustule in the hair follicles and sebaceous glands instead 

 of in intradermal galleries. 



Lesions. The skin of the legs of swine is most fre- 

 quently affected. The parasite gains entrance to the 

 hair follicles, where it produces inflammation and causes 

 depilation. The inflammatory reaction causes a redness 

 of the skin, hence the name. In a case of long standing 

 the skin is red, thick, wrinkled, cracked, practically hair- 

 less, and evolves a peculiar characteristic odor. The 

 disease extends slowly upon the animal body, and it is 

 not uncommon to find only one animal affected in spite 

 of the fact that there are many swine in the same pen. 

 Positive diagnosis can be made only by identifying the 

 parasite microscopically. 



Treatment. This condition is practically incurable, 

 at least in so far as our present knowledge is concerned. 

 Affected animals should be sent to slaughter, as this 



