PARASITOLOGY. 53 



imal becomes thin, even emaciated, and is a dejected 

 looking creature. If a scraping be made from a 

 fresh scab by aid of the knife (care being taken to 

 secure the serum from between the scab and the 

 skin) and this scraping be examined under the micro- 

 scope, the parasites may be observed. If this scrap- 

 ing be placed in a bottle and the bottle placed in the 

 sun or other warm place, the parasites will leave the 

 scab and will be seen as minute white specks upon 

 the walls of the bottle. 



Sarcoptes Scabei ; variety Suis (Suis — hog). 



Synonym. — Itch-mite. 



History. — Not common in the United States. 



Animal Infested. — It is the only species of the sub- 

 family Sarcoptidae that infests the hog. 



Condition Produced ; Symptoms. — The scab para- 

 sites may begin their propagation primarily at any 

 point on the body, though usually they begin near 

 the ears, around the eyes, on the inner side of the 

 thighs, or between the forelegs. The parasites cause 

 intense itching, the animal rubs and scratches, scabs 

 appear, the skin becomes thickened, and the hair 

 stands erect; in later stages the hair falls out. This 

 parasite has been transmitted to man and dog, where 

 it produced temporary parasitism, causing intense 

 Itching for a few days. 



Sarcoptes ScABEi ; variety ovis (Ovis — sheep). 

 Syjionym. — Face-scab parasite of sheep. 

 History. — Rare in America. 



Condition Produced. — A scabby condition of the 

 head, resembling other forms of scabies. 



