FAKMKKs' i.Xsnn IKS. 81o 



ative changes. Connective tissue forms in the region of tlic i^irasite uud 

 the cyst containing one or moic h\rvae l)e<oines spindle or h-nion shaped. 

 The hirvae is almut one twenty-lifth of an incli in length. The formation 

 of the embryos begin al)oiit the seventh day after the cysts are taken into 

 the digestive tract. The emigrating period is prolonged to the second 

 or third week and the encysting period from the fourth week to the third 

 month. After the third mouth degenerative changes begin in the cyst 

 and finally involve the larvae as well. These changes (calcareous degen- 

 eration) may take place very slowly and may not occur for a year or more. 

 When the cyst does become calcified, danger to the infested individual is 

 over. One ounce of the flesh of an infested pig it Is said, may contain 

 eighty-five thousand encysted worms.- 



Method of Infection.— Infection' occurs from eating the flesh infested 

 with the live larvae of the T. s])iralis. The source of the infection in 

 swine is from eating rats. According to the investigations made b.v Stiles, 

 rats around the country slaughter houses are quite generall.v infested 

 with trichinella. It is rare to find the oftal in country abattoirs disposed of 

 in the proper way and as rats are abundant around such places they feed 

 on this waste. Hogs frequently have the same opportunity as the rats to 

 feed on offal and under such conditions infection ma.v occur. 



Symptoms. — These have been observed in experimental animals and in 

 man. When only a few embryos migrate through the tissues, ]»ut little 

 body disiin-bance is noted. The disease is characterized by two groups of 

 symptoms; one affecting the intestinal canal, the other the muscles. 



From the beginning of the first to the end of the second week after 

 infection gastro intestinal disturbances are noticed. These symptoms are 

 not constant. The appetite is lost, the hog is depressed, abdomen tense 

 and the animal may vomit. Colicky pains accompanied by a diarrhea 

 may occur. AVhen the parasites are i»n'scul in large numl)ers it may lead 

 to a rapid death, but if only a few arc i»resent tlu> symittonis of <lisease 

 may end in this stage. 



The muscular symptoms are due to the inflammation caused l>y the 

 migration of the parasites. They are observed from the second to the 

 third weeks. The pig may rub and scratch itself. Symptoms resemblint: 

 rheumatism occur. The animal is stiff, sometimes paralyzed. Respira- 

 tions are difficult, it can hardlj' masticate and swallow its food, and the 

 voice is much changed. Oedematous tumjfactions may appear in various 

 regions and the pig loses flesh Very rapidly. The pig generally recovers 

 in about five or six Aveeks. 



Treatment.— The treatment is preventive. The offal around slaughter 

 houses shoidd be disposed of in the proper way^ Hogs should not be 

 allowed to eat this refuse and if kept around shmghter houses at all, should 

 be fed grain. If the synqttoms of the disease are marked and a correct di- 

 agnosis can be made, all that can be done is to make the anintal as com- 

 fortable as possible. As this disease is communicable to man ;md is often 



