392 Farmers’ Bulletin 1150. 
suitable tissue and develops to the hydatid. This hydatid may de- 
velop in man if an egg of the tapeworm is swallowed, and a large 
percentage of hydatid infestations in man result in death. It is 
therefore a very dangerous parasite to human beings. 
Distribution—This parasite has been found at a number of places 
in the United States proper and in Alaska, as well as in other parts 
of the world. Certain regions are found to send a large number of 
infected swine to the slaughterhouses, though its occurrence in 
sheep is comparatively rare in the United States. 
Where it is locally prevalent, its abundance may 
be attributed to infected dogs which have prob- 
ably become infected through carelessness in the 
disposal of diseased carcasses and viscera of 
slaughtered animals. Careless persons may feed 
diseased portions of carcasses to dogs or leave 
them where dogs will get at them and eat them. 
Symptoms and lesions.—The symptoms in 
sheep affected with hydatid depend on the loca- 
tion of the parasite and its size, and so are very 
variable. Where the parasite is small or~has 
room to develop without crowding important 
organs, few symptoms may be noticed. On the 
other hand, the parasite may develop in such 
Fic, 21.—Hydatid tape. Structures as the brain or heart and cause very 
Pn pa eee marked symptoms and sudden death from pres- 
magnified. (From Sure or rupture. As a rule, infestations wilh 
Stiles, 1898, after not be detected and correctly diagnosed during 
Leuckatt. ) or 2 : 
the life of a sheep and they will be found only 
on post-mortem. In such cases the large, thick-walled bladders are 
readily found. 
Treatment.—The only treatment for this condition is surgical, and 
this is not apt to be feasible in sheep, even if the disease should be 
diagnosed ante-mortem. 
Prevention.—The most important measure in the way of prevention 
of this disease is the proper disposal of carcasses and portions of 
carcasses of animals dying on the farm or killed there or elsewhere. 
The “ condemned ” tank at the modern slaughterhouse has been one 
of the greatest factors in destroying parasites of this sort, and the 
lack of an equally good arrangement at the small country slaughter- 
house and on the farm is one of the important conditions which per- 
mit such parasites to persist. Where diseased viscera, such as livers 
infested with hydatid, are thrown out where dogs can get at them, 
parasites of this kind are liable to be prevalent. The next measure 
of importance in controlling this disease is to keep dogs free from 
