204 PARASITES OF THE DOMESTIC AXI^LVLS 



"Ransom's investigations showed that under careful inspection the 

 percentage of afTected sheep in this countrj- has amounted to two per 

 cent, or more, and that approximately twenty thousand sheep carcasses 

 were retained in 1912 in abattoirs under Federal inspection on account 

 of sheep measles due to this parasite. 



''The bladder worm, Cysticercus ovis, in the meat of sheep is oval and 

 ranges in size from about one-third of a centimeter (one-eighth of an 

 inch) to almost a centimeter (three-eighths of an inch) in length. Inside 

 of this bladder there is a single tapeworm head, in which respect, as well 

 as in size, this cysticercus differs from a hydatid or a coenurus. Numer- 

 ous C3'sts, however, may be scattered through the musculature, so that 

 in their numbers there is a compensation, so to speak, for their small 

 size and lack of multiplicity' of heads. Inasmuch as the presence of these 

 cj'sts calls for condemnation of a part or all of the infested carcass, ac- 

 cording to the degree of the infestation, and the number of carcasses 

 amounts to twenty thousand a year, this parasite has considerable 

 economic interest for this countiy, and never more than at the present 

 time when the "high cost of living" is such a vital topic. 



"When one of these cysticerci from mutton is ingested by a dog, the 

 tapeworm head passes undigested to the dog's intestine and develops 

 into a fairh' large tapeworm, comparable to the gid tapeworm. Sim- 

 ilarly, this tapeworm, Toenia ovis, produces eggs which are passed 

 out with the feces of the dog, and which are ingested by sheep as 

 they graze over range or pasture or drink water contaminated by these 

 feces, 



"The parasite has been found in Europe, Africa, and New Zealand. 

 It has been found thus far in seven States in this country. It appears 

 to be particular!}^ prevalent in the AVest, a fact that is possibly related 

 to carelessness on the part of the western sheepmen as regards disposal 

 of carcasses of sheep d^dng on the range." 



Control. — ^Measures of prevention consist in restraining dogs from 

 access to the flesh of affected sheep unless it is rendered non-infective 

 by cooking. Homeless dogs should be destroyed, and others going 

 about where their excrement may contaminate the food and water of 

 sheep should be kept free from tapeworms as a precuation, not only 

 against this, but other tapeworm larvae infesting sheep. 



CcExuRosis, Gid 



Gid, turnsick, or staggers are popular terms applied to a disease of 

 the brain or spinal cord, caused by the presence in these locations of 

 the gid parasite Midticeps multiceps {Ccenwnis cerebralis), the coenurus 

 or larval stage of the tapeworm of the dog Multiceps multiceps, Fig. 113 

 (p. 179). 



