156 



DISEASES OF THE DOMESTIC ANIMALS 



man. The embryo is ingested by sheep commonly in the late fall 

 and symptoms begin a month or so later. The parasites enter the 

 biliary ducts from the duodenum and live chiefly in the liver, dis- 

 charging ova at various times which escape in the feces. After a 

 year the parasite leaves the liver but is destroyed in the large 

 intestines. It occasionally wanders into other parts of the body. 

 Lambs and yearlings are most commonly attacked and the disease 

 is enzootic. It is characterized by anemia and secondary infection 

 owing to the effect of the parasites. Loss of appetite, flesh and 

 strength, with possibly slight jaundice and enlargement of liver 

 (early stage) ; dropsy and general exhaustion, with diarrhea or 

 constipation, are seen. Diagnosis is only positive by finding 

 parasites post mortem in the liver, or, in the feces the ova may be 

 seen with a microscope during life. Very fatal in sheep ; much less 

 so in cattle. 



Treatment. — The treatment is wholly preventive. Salt should 

 be given patients liberally. Lime and salts, or copperas (250- 

 400 lbs. to acre), may be sprinkled on the pastures from May to 

 August. The embryos are ingested in water or eaten while en- 

 cysted on grass. A small snail (1/5 in. long) is the intermediary 

 host and wet grounds are its home. Draining pastures is the chief 

 desideratum. Infested animals should be slaughtered and their 

 livers burned. If the pastures are greatly infested they must be 

 given up and high, dry pastures employed. Overstocking leads to 

 close grazing and greater chance of the animals ingesting the em- 

 bryos at the lower part of the grass. The manure of infested ani- 

 mals must be disinfected with lime. 



Louping 111. 



This disease attacks sheep and more often lambs in spring. 

 It begins with twitching and trembling of the muscles and fits, in 

 which the animal falls and may then leap into the air. Paralysis 

 follows, paraplegia more often, but also of the fore legs, and the 



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