474 Pork Production 



and a small mite that burrows under the epidermis. 

 The former is the most common louse, and the latter 

 is the least common of the sarcoptic mites occurring 

 in domestic animals. The mite is of little economic 

 importance. 



The favorite points of attack of the hog-louse are the 

 under surface of the body, neck and inside of the thighs. 

 The irritation to the skin is severe. Young hogs that are 

 badly infested may be so restless and lose so much blood 

 that they become unthrifty. 



It is very difficult completely to rid a drove of hogs of 

 lice. The most satisfactory method is to practice dipping 

 at frequent intervals. The most effective agent for de- 

 stroying hog-lice is crude oil. The layer of oil on top of 

 the water in the dipping tank should not be less than one 

 inch thick. Crude oil may be applied to the bodies of 

 the hogs with a sprinkling pot or swab. If this method 

 is practiced, it is advisable to crowd the hogs into a small 

 pen. This may be done in cold weather when it is impos- 

 sible to dip them. 



The most common internal parasites of hogs are the 

 round worms. They infest the lungs, intestines, and 

 abdominal cavity. The Ascaris suis which inhabits the 

 small intestine and liver is the most common intestinal 

 worm. It varies from 4 to 10 inches in length. Other 

 intestinal worms are the whip worm, Trichocephalus 

 crenatus and the pin worm, CEsophagostoma dentatum. 

 The former is about 2 inches long and inhabits the first 

 division of the large intestine, and the latter is about 

 .5 inch long and inhabits the posterior portion of the large 

 intestine. The thorn-headed worm, Echinorhynchus gigas, 

 is a common intestinal parasite in some sections of the 

 country. It is usually found with its proboscis or thorn 



