Common Parasites 



21 



Parasites of Hogs 



EXTERNAL. PARASITES. 



Hog Lice (Haematopinus suis). 



This is the largest species of louse found infesting farm animals. 

 The fully developed female is one-fifth inch long by one-tenth inch 

 a broad. The male is some- 



what smaller. There are but 

 few herds of hogs not infested 

 with lice. They are perhaps 

 the most common parasites 

 found on farm animals, they 

 are easily found. By prefer- 

 ence they locate on those parts 

 of the animal where the skin 

 is thin and easily punctured. 

 The louse obtains its food by 

 puncturing the skin of its 

 host and sucking blood. The 

 presence of lice causes irr'ta- 

 tion and roughening of the 

 skin, a run down appearance 

 and condition. The injurious 

 effects of lousiness frequently 

 cause the death of young pigs. 

 The presence of lice makes 

 hogs more susceptible to dis- 

 ease than they would other- 

 wise be. 



Life History. The female 

 louse deposits eggs (nits) 

 upon the hair of the hog, ce- 

 x 15. menting them tightly to the 

 hair. The eggshell has a lit- 

 tle "trapHdoor at one end which opens and allows the escape of the 

 young louse when it is fully developed. The young louse may attack 

 the host immediately or, if brushed off in the nest or elsewhere, soon 

 seeks a host. Here it reaches maturity and the egg-laying stage in 

 a few days. 



Treatment. On a farm free of hog lice these parasites may gain 

 entrance to the swine herd along with new breeding stock. Ani- 

 mals brought to the farm for service may carry them. The custom 

 of borrowing and lending breeding animals is one fraught with 

 great danger to the herd. Not only may lice be brought to the farm 

 by this means but various other external and internal parasites and 

 contagious diseases are often carried in like manner. When new 



Fn;. ]. Dorsnl view of female hog louse, 

 a, antennas b, eye; r, spiracles; d, proboscis or 

 haustellum. 



