THE TAPEWORM LARV^ 



205 



It is observed most often in sheep, more rarely in cattle, goats, and 

 other ruminants. It has been reported in the horse. 



Occurrence. — Gid is a common disease in Europe where it has been 

 known for many years. The parasite has been observed in this country 

 at least as early as 1901, though symptoms which were undoubtedly 

 those of gid were authentically reported from our far western flocks 

 during at least ten years preceding. 

 In 1909 Taylor and Boynton foimd 

 an outbreak in a flock of sheep about 

 forty miles from Ithaca, New York. 

 Necropsies in these cases revealed 

 the presence of the gid parasites 

 from which, by feeding to dogs, 

 they claim to have raised the adult 

 tapeworm. This is the first authen- 

 tic instance of gid in the Eastern 

 United States, and the first account 

 of it was given by Dr. James Law, 

 of Cornell University, in a paper 

 read before the New York State 

 Veterinary Medical Society in the 

 same year. 



In view of the large number of 

 sheep and dogs which have been 

 brought to the United States from 

 countries where gid prevails, it is 

 somewhat remarkable that the dis- 

 ease has not been more often ob- 

 served here. It is probable that nu- 

 merous cases have occurred which 

 have passed unrecognized and con- 

 sequently imrecorded, the symptoms 

 being ascribed to other causes. It is 

 certain that it now has a foothold in 

 this country, in view of which fact, 

 and the further one that in other countries it is one of the most de- 

 structive parasitic diseases of sheep, veterinarians and sheep raisers 

 should be on the lookout for it and take proper preventive precautions. 



The Coenurus. — The completely developed coenurus (Figs. 114 and 

 116) consists of a membraneous vesicle which may vary in size from that 

 of a hazelnut to that of a hen's egg. When located on the brain it tends 

 to assume a spherical form; when on the cord, which is more rare, it 

 becomes adaptively elongated. The wall is thin, translucent, and dis- 

 tended by a colorless fluid. On the surface of the vesicle there are little 



Fig. 113. — Portions of adult gid tape- 

 worm (Multiceps multioeps) , — natural size 

 (after Ransom, from Railliet, Bull. No. 66, 

 Bureau An. Ind., U. S. Dept. of Agr.). 



