THE DIGESTIVE SYSTEM 49 



tion can be materially diminished by keeping the quarters 

 clean. The droppings should be gathered and limed, 

 and the floors in the piggery should be kept clean, and 

 limed or sprayed with^some agent that is destructive to 

 the egg and embryo of the ascarids. Common salt 

 destroys the embryo and larvae of practically all animal 

 parasites, but it must be used with caution in hog premises, 

 for it is also quite destructive to hogs. 



Treatment of individual hogs by giving direct medi- 

 caments is difficult. The most effectual method of 

 medicating swine, particularly when large numbers are 

 to be treated, is accomplished by medicating the slops 

 or feed. Santonin and areca nut have been used, but 

 other less expensive and as effectual drugs may be selected, 

 such as ferrous sulphate, copper sulphate, and creosote. 

 When drugs are mixed with slops or feed, care must be 

 used to have a thorough mixture, and each hog should 

 obtain its proper portion. The medication in slop or 

 food should be given once a day and continued for several 

 days. The excrements laden with the worms and their 

 ova should be properly disposed of in order that future 

 infestation may be diminished. 2 



Esophagostoma Dentatum 



Esophagostomiasis is a disease caused by the invasion 

 of the Esophagostoma dentatum into the submucosa 

 of the large intestine of swine, a condition not very 

 common in America. This parasite is parasitic in its 

 larval stage. Its life cycle has not been entirely worked 

 out, but the ova are discharged from the animal body 

 in the feces and hatch, if climatic conditions are favorable, 

 into embryos. Later changes are unknown, but the 

 larvae are ingested with food or drink and bore into the 

 submucosa of the large intestine, where they remain 

 from six to seven months and produce small nodules 



2 The external covering of the ascarids contains a volatile chemical 

 substance that is extremely irritating to the ocular mucous membrane, 

 and care should be exercised that the hands be carefully cleansed after 

 handling these worms and thus prevent the development of conjunc- 

 tivitis. 



