1922. j 



Liver Rot in North Wales, 1920-21. 



L57 



died while the flukes, although actually present in great num- 

 bers, were frequently so small as to pass unnoticed even when 

 the livers were examined. Again it was often contended that 

 the disease was not endemic on the farm on which animals 

 died, hut had been imported from some other district, the 

 sheep having been infected prior to purchase. This idea also 

 proved to be erroneous in the majority of cases, and it was 

 generally possible to demonstrate this to the farmers concerned 

 by taking all the facts connected with the flock, and surveying 

 the land. By these methods the actual place where infection 

 had taken pla<3e could often be demonstrated. On a number of 

 farms cattle were also affected, and in one instance over 30 

 died. Three flukes were obtained from the liver of a pig — the 

 only instance reported. 



As to the actual loss, it was found impossible to get even 

 an accurate estimate, the data being incomplete, and many 

 cases were very complicated. Very heavy individual losses 

 were frequent, and reckoning only the price of those which 

 died on the farm, and the difference between buying and sell- 

 ing price, these individual losses ranged from £50 to £1,500; 

 £400 to £800 being frequent figures. In addition, there is the 

 loss of the expected lamb and wool crops, etc. Many methods 

 were recommended and tried during the year to endeavour to 

 maintain remains of flocks free from further infection, and to 

 prevent the infection of fresh flocks purchased during the 

 autumn of 1921. Many farmers had to give up sheep keeping- 

 Cat any rate for a time). Others, after survey of their land, 

 were able to keep reduced flocks on their drier fields. Others 

 fenced out or ploughed infected fields or parts of fields. Con- 

 siderable drainage was undertaken, there being no doubt what- 

 ever that certain cases were aggravated by neglect of ditches, 

 etc., especially during the war period. The majority now 

 recognise the dangers, and that is the great step to prevention, 

 although there is always a small residue who cannot be reached 

 by visit, leaflet, lecture or press. It is gratifying to be able to 

 record that taken as a whole, the agricultural community have 

 shown interest in the scientific side of the work, and have 

 been most helpful as regards data, experiments and in many 

 other ways. 



Causes Leading up to the Outbreak. — In a previous paper 11 

 the close connection between soil characters, meteorology, and 

 the relative distribution and abundance of L. truncatula, the 



* Parasitoloyy, op. cit. 



