154 SWINE DISEASES 



necessary to apply chloroform or some penetrating anti- 

 septic to cause the larvae in the deeper tissues to migrate to 

 the surface, or at least to move energetically in order that 

 they may be located and removed. The wound should 

 be properly dressed and protected against future infesta- 

 tion. It is always well to observe the wound on the 

 second day to make certain that all larvae have been 

 removed. However clinicians report that this line of 

 treatment is wholly ineffective, claiming better results are 

 obtained from the treatment for screw- worm in festation 

 given on page 123. 



Flea Infestation 



Representatives of the order, Siphonaptera, constantly 

 inhabit hog houses and pens in some sections of the 

 country. These parasites are blood suckers and obtain 

 their nourishment directly from the swine, but do not 

 appear to cause any serious trouble. No doubt they 

 produce some irritation where they pierce the skin, and 

 swine thrive better in their absence. Fleas breed 

 in filth, the ova being deposited in fecal matter or 

 other filth. The larval and pupal stages also take place 

 in filth and in the soil, the entire cycle from adult to adult 

 requiring about one month. 



Fleas may be lessened in number and ultimately 

 eradicated from most premises by persistent cleanliness 

 and by dipping the swine in some standard dip every 

 ten days for a period of six weeks. 



Lousiness (Phthiriasis) 



Phthiriasis, or lousiness, is the most common para- 

 sitic disease of swine. The hog louse, Hematopinus suis, 

 is a blood-sucking louse and one of the largest of known 

 lice. The adult ovigerous female cements the ova on 

 the hair behind the ears, in the flank region, and else- 

 where. The ova hatch into small lice in from ten days 

 to two weeks. These lice do damage by direct abstrac- 

 tion of blood and by irritation of the skin, which causes 

 more or less of pruritis. This makes the swine restless 



