534 DISEASES OF CATTLE. 



" turnsick," or " staggers,'' deserve mention, as they are rather com- 

 mon among sheep in the northwest. As already alhided 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. 532). 



Cattle harboring this parasite show symptoms indicating an affec- 

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

 gait, impaired vision, etc. 



Treatment consists in trephining the skull and removing the para- 

 site, an operation which requires a skillful operator and is frequently 

 unsuccessful. Unless the parasite is removed affected cattle almost 

 invariably die. 



TAPEWORM CYSTS IN THE MUSCLES, BEEF MEASLES.* 



Small tapeworm cysts (Tcenia saginata)^ about the size of a pea, 

 found in the muscles of cattle 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 Avhere they wall contaminate 

 ^'^i 28.-Thin-necked ^j f ^ drinking Water. 



bladder worm (Twma _ _ => 



hydattgena) trom Bh- This parasite is very common in cattle in the 

 ^ZT^ '^''''' ^"^ ^ United States, at least 1 per cent being infested. 

 x\s 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 by 

 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 

 in the United States. 



THREAD WORMS IN THE ABDOMINAL CAVITY. 



Thread worms {Setaria lahiato-papillosa) 2 to 4 inches long are 

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

 or no trouble. The embryos produced by these worms enter the 



1 For further information consult Bureau of Animal Industry Circular 214. 



