THE ANIMAL PARASITES OF CATTLE. 



539 



human beings on account of the danger of infecting them with hyda- 

 tids, which develop in man if the eggs of the hydatid tapeworm are 

 swallowed. 



Thin-necked hladder worjns {Tcenia hydatigena^ fig. 28) are most 

 commonly found attached to the mesentery and omentum. Tliere is 

 no medicinal treatment. 



Fig. 27. — Hydatids (Echinococcus (jranuloaiis) in portion of hog"s liver. 



TAPEWORM CYSTS I.\ THE MUSCLES, BEEF MEASLES. 



Small tapeworm cysts {Taenia saginata)^ about the size of a pea, 

 found in the muscles of cattle (fig. 29) are the larvae of the common 

 tapeworm of man. Cattle become infected from feed or water which 

 has been contaminated by the feces of persons 

 harboring the adult tapeworms, and human beings 

 in turn become infected by eating raw or rare 

 beef infested with the larval stage (measly beef). 



To prevent cattle from becoming infested with 

 this parasite care should be taken that human 

 feces are not placed where they will contaminate 

 the feed or drinking water. 



Fig. 28.— Thin-necl?ed 

 f"I''* bladder worm (Tffnio 



hydatigena) from ab- 



Bladder worms {Mvltlceps multiceps, or Cmnu- g®™^'"'' ^^"""^ °^ ^ 

 mis cerehraUs) which are ocasionally found in the 

 brain of cattle^ and cause gid, " tumsick,'"' or " staggers," deserv^e 

 mention, as they are rather common among sheep in the Northwest. 

 As already alluded to, these worms are the intermediate stage of a 

 tapeworm found in dogs, and their life history and the means of pre- 

 venting infection have been briefly discussed above (see p. 538). 



