Taenia hydatigena: a cause of persistent liver condemnations in lambs.

A problem of high levels of liver condemnations which had affected bought-in lambs fattened on a North Yorkshire farm for several years was investigated. Because the farmer spread pig slurry on the land, migrating Ascaris suum larvae were initially suspected as a cause but the investigation eliminated this possibility. Migrating Taenia hydatigena larvae were found in tissue sections and isolated from livers. A combination of parasitological and serological evidence using oncospheral antigen in an ELISA suggested that infection was occurring immediately before the arrival of lambs on the farm, although a source of infection on the farm was also identified. Peak liver condemnations occurred in December-January. Possible reasons for this are suggested and the relevance of these findings to national liver condemnation losses are discussed.