PARASITIC INSECTS AND MITES 239 



through the wool. The loss due to the damage to the fleece is 

 usually greater than that resulting from unthriftiness. 



The hog-louse is the largest specie known. As well as the 

 largest, it is the most common of all lice found on domestic ani- 

 mals. The favorite points of attack are the under surface of 

 the body, the neck and the inside of the thighs. The irritation 

 and itching are severe, and the hog rubs and scratches the skin. 

 Young hogs suffer most from this parasite, and their thriftiness 

 is greatly interfered with. 



The long-haired breeds of dogs suffer more from lice than 

 the short-haired breeds. The almost constant scratching and 

 biting of the skin result in its becoming badly irritated and 

 scabby. The symptoms differ little from irritation to the skin 

 caused by fleas, but the presence of biting or sucking lice en- 

 ables the person making the examination to determine the cause 

 of the irritation. 



Lice are the most common parasites of poultry. It is un- 

 common to meet with a flock of fowls that are not hosts for one 

 or more of the many different varieties of bird lice. Restless- 

 ness, picking, scratching, flapping the wings, abandoning the 

 nest and loss of condition are common symptoms. Young birds 

 suffer most from lice. This is especially true of young chickens, 

 death frequently resulting. Old fowls may show little incon- 

 venience unless badly infested. The finding of the lice with the 

 head imbedded in the skin or on the feathers enables the person 

 making the examination to positively diag-nose the case. The 

 head, back, region of the vent and beneath the wings are the 

 parts that should be carefully examined for lice. 



Treatment of Lousiness. — The preventive treatment is very 

 important. This consists in carefully examining all animals 

 or birds that have been purchased recently, and if found to 

 harbor lice, excluding them from the herd or flock until after 

 they have been properly treated. 



It is impossible to rid animals of lice if the quarters are not 



