[Field studies on the incidence of damage to the liver caused by migrating Ascaris larvae in baconers and its treatment (author's transl)].

A preliminary report on some results of a deworming trial. Of a large number of pig-breeding farms, ten were selected for a deworming trial in the integrated groups of Deurne and Aarle-Rixtel during a period of preliminary investigation from May 30, 1973 to December 2, 1973. The proportion of livers condemned on six of these commercial pigbreeding farms was higher than the average reported by the Central Bureau of Statistics. A difference in growth of 40 grams daily between baconers without white spots and those with totally involved livers was recorded. The anthelmintics dichlorvos, levamisole and mebendazole produced a marked improvement in daily growth and reduced the degree to which the liver was involved. Levamisole was obviously the most effective agent. The most satisfactory results are obtained on administration of anthelmintics at the time when fattening is started. The results obtained when the course of anthelmintic treatment is repeated, are not any better than those obtained in a single course of treatment.