Diseases of the Skin. — External Parasites. 201 



rise to it. Filth and neglect favour parasitic development, 

 but do not of themselves produce the disease. 



Symptoms. — Ordinary or sarcoptic mange is characterised, 

 at its earliest period, by intense itching. If the skin of the 

 affected part is examined, there will be observed small 

 red points like flea-bites. These eventually become 

 pustular, and break, exuding a serous fluid, which pro- 

 duces thick, dark crusts, which are ultimately cast off, 

 leaving the part denuded of hair, and of a bleached appear- 

 ance. 



The violent scratching attendant on the affection 

 throughout, creates extreme soreness, and frequently open 

 wounds. The hair about the affected region becomes 

 matted together, and the animal is rendered an object of 

 •disgust and pity. 





.1* 







V 



Fig. 22 

 Sarcoptes Canis. 



Fig. 23. 

 acarus folliculorum. ma- 

 TURE Specimens, a, Mouth ; 

 i>, Papillae on each side ; c, 

 (Gerlach.) Feet. (Fleming.) 



The disease, it not checked early, rapidly extends to the 



