DIGESTIVE SYSTESI 141 



brane is found and upon which daughter and granddaughter cysts 

 and the head of the future tapeworm may be seen. The cyst contains 

 a pale straw-colored, limpid serum. The mutilocular cyst is a mass 

 of single cysts developing on the outside of the true cystic mem- 

 brane instead of developing on the inside, as in the polymorphous 

 cyst. The cysts necessarily displace and by pressure destroy liver 

 tissue. Old cysts contain a cheesy or caseous substance; in some 

 instances a purulent substance. 



Symptoms. — Chemical evidence of the presence of hepatic echin- 

 ococcus cysts are usually wanting. A few cases of ascites associated 

 with hepatic echinococcosis have been recorded. There may be icterus 

 and some digestive disturbance. 



Treatment. — Because of the location and nature of the lesion, treat- 

 ment for echinococcosis is ineffectual. The condition is readily pre- 

 vented by treating with teniafuges all valuable dogs that are as- 

 sociated in any wav with the swine and by destroying all worthless 

 curs and properly disposing of their carcasses. 



Cijstieercosis 



Hepatic cysticercosis of swine is not very common. It is found 

 principally in young pigs, where it is the result of invasion of the 

 liver with embryos of the Taenia marginata of the dog. These em- 

 bryos are obtained in food that has been contaminated with dog 

 feces. They gain entrance to the liver by way of the portal vein. 

 Some of the embryos pass out of the liver in the hepatic vein ; others 

 bore through the organ and its capsule into the peritoneal cavity. 



Lesions. — In extensive invasion the liver is enlarged. There may 

 be evidence of perihenatitis. A small elevation may occur upon 

 the surface and in each elevation a small opening may be observed. 

 The liver is of a variegated color, due to alternating areas of hemor- 

 rhage and degeneration. 



Symptoms. — Unthriftiness, weakness, anorexia, and increased thirst 

 may be observed in hepatic cvsticercosis. The affected animals may 

 become rapidlv emaciated; there mav be evidence of peritonitis — 

 and in exceptional cases the animals may die suddenly, but as a rule 

 they linger for several weeks. 



Treatment. — Svmptomatic treatment may be resorted to. but it is 

 doubtful if satisfactory results will be obtained. This condition may 



