30 Georgia State College of Agriculture 



Parasites of Sheep 



EXTERNAL PARASITES. 



Sheep Louse (Trichodectes spherocephalus) . 



Lousiness is a somewhat common trouble with sheep. Sheep 

 lice of the above species are not blood suckers but live upon the 

 substance of the surface of the skin. They cause irritation and 

 restlessness, loss of condition and emaciation. 



FIG. 21.- Sheep louse (Trichodectes sphcerocephahis) : a, female ; &, antenna; c, d, dorfial and 

 side view of leg. Enlarged. (After Osborn, 1896 ; Bui. No. 5, Div. Entomology, Dept. Agr,) 



Life History. All lice produce eggs. Sheep lice hatch from eggs 

 cemented to the wool fibres and pass the entire life on sheep. 



Treatment. Dip the infested flock in a 2 per cent solution of 

 cresol disinfectant. Spray and disinfect the stables or sheds occu- 

 pied by the infested sheep with a somewhat stronger cresol solu- 

 tion to which has been added sufficient air slaked lime to mark 

 where it is applied. A second dipping a week later should rid the 

 flock of lice. 



Sheep Tick (Melophagus ovinus). 



This is in reality a wingless fly. It is a very common parasite of 

 sheep. Mature specimens are about % inch long, the body being 



