LIVER ROT 665 



slightly different direction each time to give it a greater 

 chance of success. If no benefit or only partial success 

 follows within three or four days, the operation should be 

 repeated, and this may require to be done two or three times 

 more before a complete cure is effected. In districts which 

 are much subject to this disease, to ensure the destruc- 

 tion of the embryo worms the skulls of dead sheep should be 

 broken up and their carcases buried with quicklime in a com- 

 post heap. The dogs ought also to be dosed regularly with 

 J drachm to I drachm of areca nut, which frees them from 

 tape-worms, and lessens the risk of sheep, while feeding on 

 grass, picking up segments of the worms passed by dogs. 



Darnel rye-grass (Lolium temulentum), an annual weed 

 in some pastures, is reputed to produce in sheep brain 

 symptoms similar to those of sturdy. 



Liver Rot. There have been enormous losses in this 

 country from " rot " in sheep, the work of a trematode worm, 

 Distomum hepaticum or Fasciola hepatica, which is the cause 

 of the disease. The " fluke," seldom more than an inch long, 

 broad, thin, flat, and flounder-like, attaches itself by a sucker 

 on the under surface. Sometimes hundreds have been found 

 in the liver ducts of one sheep. Professor Leuckart in 

 Germany, and A. P. Thomas in this country, traced, almost 

 simultaneously, the life-history of this parasite through all its 

 different stages, and published independent accounts of their 

 investigations in I882. 1 They find that the fluke lives for a 

 time, and changes its form, in the body of a minute shell- 

 snail, Limnaus truncatulus, which thrives in excessively wet 

 places. 



The sequence of changes in the animal system is 

 originated by irritation, and consequent inflammation, 

 beginning in the biliary ducts, and extending through the 

 liver, interfering with the performance of its functions in 

 aid of digestion. The stomach next becomes weak or 

 disordered, poor and imperfect blood is formed, and time is 

 all that is necessary to exaggerate the results into a persistent 

 anaemia, which ultimately ends in death. 



The great means of prevention are to surface- or under- 

 drain; to keep sheep from pasturing on flooded land; to 

 have lumps of rock salt about the pasture; and to give 

 1 See fa* Journal of the Royal Agricultural Society'for that year. 



