658 DISEASES OF SWINE 



form of itch as a result of infestation with this scab mite. The 

 treatment for the condition in man is not much different from that 

 in swine. Thorough washing of the hands and arms with a strong 

 soap-suds, followed by application of a sulphur ointment, will 

 destroy the mites. The sulphur application may cause some inflam- 

 mation of the skin, but this can be rapidly relieved by applying cold 

 cream or other soothing ointment. 



ROUND-WORM (ASCARIS SUILLA) 



The common round-worm which is found in the intestines of the 

 hog is known in scientific works as the Ascaris suilla. This is one 

 of the most common parasites of the intestines of the hog, and is 

 found widely distributed among the herds in the United States as 

 well as in Europe. In the large packing-houses at Chicago, Kansas 

 City, and Omaha these parasites are found in large numbers in 

 nearly half of the animals that are slaughtered at these points. 



Description. — The Ascaris suilla is a round worm, pinkish or 

 yellowish-white in color. The body is round, firm and elastic, and 

 tapers at each end. The head end of the parasite tapers more 

 markedly than does the tail. The female worm is larger than the 

 male, and will average about 11 inches in length when fully matured. 

 The male parasite when completely developed averages about 7 

 to 10 inches in length. The male worm is further differentiated 

 from the female by the fact that it has a curved tail, while the 

 female has a straight hind extremity. 



The parasite when examined under the lens will be found to 

 have a small head located at the anterior extremity, which is recog- 

 nized by the fact that it is the most pointed. If this head be closely 

 examined it will be found to possess a mouth which is provided with 

 three lips. 



These worms have a complete, fully developed digestive appara- 

 tus, and can take up food from the contents of the intestines and 

 digest it. They are not blood-suckers and do not draw blood from 

 the mucous membrane. 



The manner of reproduction and infection of these parasites is 

 very simple. The female parasite becomes filled with eggs, and 

 these are laid in the bowel, where they become mixed with the 

 intestinal contents and are carried out with the feces. These eggs 



