VETERINAEY MEDICINE. 887 



sheep-measle parasite, remarks on morphology and comparison with other 

 species, distribution in the body, diagnosis of sheep measles, geographic distribu- 

 tion, prevalence, economic importance, significance in meat inspection, prophy- 

 laxis, etc. 



Sheep measles, or tapeworm cysts in mutton, were first recorded in England 

 in 1SG6, and the parasite named C. ovis in 1S69 by Cobbold. C. ovis has usually 

 been considered identical with C. ccllulosce, the pork-measle parasite, and has 

 also been confused with C. tenuicollis. It is, however, the intermediate stage of 

 a dog tapeworm, Ta'iiia ovis. It may attain its full development in sheep in 

 less than 3 months after infection and in the dog the tapeworm may reach the 

 egg-producing maturity in 7 weeks after the ingestion of the cysticercus. 



" C. ovis is commonly limited to the heart or diaphragm, but not infrequently 

 occurs in the muscles of mastication and tongue and sometimes in various 

 locations in the musculature. It may occur in the limgs, the wall of the 

 esophagus, or the wall of the stomach. Doubtful locations are the kidney and 

 liver. It is esseutially a parasite of the intermuscular connective tissue and 

 is evidently rare in other locations. The cysticerci seen by meat inspectors are 

 usually degenerated. Those located in the heart tend to degenerate early. 

 Degeneration may be well established in less than 3 months after infection. 

 Either partially grown or fully developed cysticerci may degenerate and may 

 be associated with living cysticerci in the same carcass as a result of variations 

 in longevity of the parasites or of repeated infections. 



" There is no known method of diagnosing the presence of C. ovis in the liv- 

 ing animal. The parasites are to be lecognized in the sheep carcass by their 

 location in the musculature, by their small size, and by the lateral position 

 of the head of the cysticercus, G. tenuicollis being found in relation with serous 

 membranes, being of larger size when fully developed than C. ovis, and having 

 its head in an apical position with reference to the caudal bladder. In soma 

 cases microscopic examination may be required to differentiate between these 

 2 species. The possibility exists of confusing degenerate cysticercus cysts 

 with Sarcocystis cysts and with encysted foreign bodies, such as plant barbules." 



Sheep measles probably occurs wherever sheep are attended by dogs, but 

 has not yet been found in sheep known to have originated in the eastern 

 United States. " Over 17,000 of the sheep slaughtered under federal supervi- 

 sion during the year 1912, prior to December 1, were found to be affected with 

 measles. With the development of more efficient methods of inspection for 

 C. ovis the number of cases detected will be relatively much more numerous. 

 The number of infested sheep in the Western States probably exceeds, on the 

 average, 2 per cent of the total number. Young sheep, not over 2 years of age, 

 apparently are more likely to show infestation than old sheep. 



"G. ovis is of economic importance, first, because of the losses resulting from 

 the condemnation of carcasses found by the meat inspector to be more or less 

 heavily infested, and, second, because of the direct losses which probably occur 

 among sheep as a result of the invasion of the parasites. The extent of these 

 losses can not be estimated at present. 



"C. ovis is of special interest in meat inspection because it affects the mus- 

 culature and because it is so prevalent. Carcasses which are only slightly 

 infested may properly be passed for food after the removal of the parasites, 

 but carcasses showing a heavy infestation should be condemned. Moderately 

 infested carcasses may be rendered into edible tallow, but are usually treated 

 the same as condemned carcasses and are manufactured into fertilizer and 

 other inedible products. As C. ovis is not transmissible to man, meat-inspection 



23666°— No. 9—14 7 



