THE DOG AS A CARBIEE OF PARASITES AND DISEASE. 11 



One preventive measure for suppressing gid is, of course, to destroy 

 the brains |nd the coenuri of giddy animals, which can be done by 

 burning them or by breaking the skull and covering the brain with 

 formaldehyde, sheep dip, or some similar substance. Another meas- 

 ure is to administer a vermifuge to sheep dogs and so rid them of 

 their tapeworms, and to do this often enough to keep them free 

 from tapeworms. But it is obviously of little avail to a sheepman 

 to have his own dogs free of tapeworm if his neighbor's dogs or 

 ownerless dogs or strays of any sort are free to carry tapeworm 

 onto his range or pasture and infect the grazing and thereby infect 

 his sheep. From losses originating in this way he must be pro- 

 tected by measures looking to the restraint of dogs that recognize 

 an owner and the elimination of those that do not. 



Gid has been reported from several States in this country, but it 

 is most prevalent in Montana, especially in the northern half of 

 that State, where gid has had a foothold for a quarter of a century 

 and where the losses for some years total about $10,000. There is 

 evidence of the occurrence of gid in Arizona, and outbreaks have 

 occurred in recent years in New York, Iowa, and Kansas. There 

 have been reports, apparently correct, of its occurrence in Ohio, 

 Illinois, Michigan, Missouri, Oklahoina, and Nevada. It is a con- 

 stant source of loss in many European countries, and at variolis 

 times has proved a veritable scourge to the sheep industry of these 

 countries. 



CYSTICERCUS (MEASLES) IN SHEEP AND OTHER ANIMALS. 



Muscular cysticercosis < {" Tneasles ^^) in sheep. ^-The presence of 

 small bladder worms in mutton has recently been shown by Ransom * 

 to be much more common than had been suspected, and to be due to a 

 tapeworm in the dog and not to a tapeworm of man as had been 

 supposed. His investigations showed that under careful inspection 

 the percentage of affected sheep in this country has amounted to 2 

 per cent or more, and that approximately 20,000 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 (fig. 6) , 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, 

 ip which respect, as well as in size, this cysticercus, as it is called, 



^ Cysticercus oviSj the cause of tapeworm, cysts in mutton. By B. H. Ransom. Journal 

 of Agricultural Research, U. S. Department of Agriculture, vol. 1, pp. 15-58. 1913. 



