Oct. 10,1913 
Cysticercus Ovis 
53 
reach the egg-producing maturity in seven weeks after the ingestion of 
the cysticercus. 
Cysticercus 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 
lungs, the wall of the esophagus, or the wall of the stomach. Doubtful 
locations are the kidney and liver. It is essentially 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 three 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 Cysticercus 
ovis in the living animal. The parasites are to be recognised 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, C. 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 some cases microscopic 
examination may be required to differentiate between these two species. 
The possibility exists of confusing degenerate cysticercus cysts with 
Sarcocystis cysts and with encysted foreign bodies, such as plant barbules. 
Sheep measles have been reported from England, France, Germany, 
Algeria, German Southwest Africa, and New Zealand and have been 
found in sheep from seven Western States of this country. It 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 (p. 45). 
Over 17,000 of the sheep slaughtered under Federal supervision 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 Cysticercus 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 infesta¬ 
tion than old sheep. 
Cysticercus 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. 
Cysticercus ovis is of special interest in meat inspection because it 
affects the musculature and because it is so prevalent. Carcasses which 
