PHTHIIUASIS. 



609 



the goat from the ILcmatopma, steiinps and the TrirhHl'des climax, and 

 the pig from the T[,eiiuitopiinis »r/((.s. 



_ The symptoms are, with trifling variations, the same in all domestic 

 animals the prmcipal being rubbing and itching. The animals scratch, 

 bite and attempt to rub against hard objects, even abrading the skin 

 when this is thin and the irritation is severe. 



The parasites may, however, remain localised, and it rarely happens 



Fig. 247. — Sheep louse (Trichoccphahis spharocrplialns). a. Female; 6, antenna ; 

 c, d, dorsal and side view of leg. Enlarged. (After Osbom, 1896 ; Bui. No. 5, 

 Div. Entomology, Dept. Agr.) 



that they are present in any considerable number in all parts of the 

 body. 



In the ox thej^ are principally found in the depression at the back 

 of the base of the horns, and in the upper margin of the neck and the 

 back. In the absence of treatment phthiriasis may become generalised 

 over the entire surface of the body. 



The trichodectes and the melophagus of the sheep choose similar 

 points, but when the wool is long they may be found nearly all over 

 the body. 



In the pig the hsmatopinus is found on the neck, in the region of 

 the poll, about the armpits, and round the eves and easr. 



D.c. 



R R 



