AXIMAL PARASITES OF CATTLE, 529 



"turnsick," or "staggers." deserve mention, as the}^ are rather com- 

 mon among sheep in the Northwest. As already^lluded to, these 

 worms are the intermediate stage of a tapeworm found in dogs, and 

 their life history and the means of preventing infection have been 

 briefly discussed above (see p. 527). 



Cattle harborhig this parasite show symptoms indicating an affec- 

 tion of the brain, walking or turning in circles, dizziness, uneven 

 gait, impaired visioil, etc. 



Treatment consists in trephining the skull and removing the para- 

 oite, an operation Avhich requires a skillful operator and is frequently 

 unsuccessful. Unless the parasite is removed affected cattle almost 

 in\-ariably die. 



TAPEWORM CYSTS IN THE MUSCLES, BEEF MEASLES.^ 



Small tapeworm cysts {Tmua sarjlnata). about the size of a pea 

 found m the muscles of cattle are the larv* of the common tapeworm' 

 of man. Cattle become infected from feed or 

 v.ater which has been contaminated by the feces 

 of persons harboring the adult tapeworms, and 

 human beings in turn become infected by eating 

 raw o]' rare beef infested with the larval stage 

 (measly beef). 



To prevent cattle from becoming infested Avith 

 this parasite care should be taken that human 



PIC. ...-Thin-nocKed ff""'! '? ""^^ ^'''"""^ '''^'^''^ ^^'^y ^'^^ Contaminate 

 bladder worm ciwiiia ^^'^^ ^^^^l or drmkiug Water. 



S^r^luv",?^ ,.^!^^! 1^^^'^^^^^ ^« '-^'y ^«^^^^^«^^ in cattle in the 

 steer. «- "itcd J^tates, at least 1 per cent being infested. 



As a result considerable loss is entailed through 

 condemnations of beef carcasses by meat inspectors, because of the 

 presence of tapeworm cysts. All this loss could be avoided and 

 the danger of tapeworm infestation in human beings from this 

 source could be removed by the observance of proper precautions in 

 disposing of human excreta. At the same time much sickness and 

 many deaths from diseases (hookworm, typhoid fever, etc.) caused bv 

 soil pollution would be prevented, and farm life would be rendered 

 much safer than under the poor sanitary conditions which are re- 

 sponsible for the high percentage of tapeworm cysts among cattle 

 111 the United States. 



THREAD WORMS IN THE ABDOMINAL CAVITY. 



Thread worms {Setaria labiafo-papaiosa) 2 to 4 inches long are 

 frequently found in the abdominal cavity. Thev seem to cause little 

 or no trouble. The emln-yos produced by these worms enter the 



^ For furthov informatiou consult Bureau of Animal Industry Circular 214. ' 



54703°— 2.3 34 



