Parasitic liver damage in lambs with particular reference to the migrating larvae of Ascaris suum.

It has been suggested that the larvae of the pig nematode Ascaris suum is a possible cause of rejection of lambs' livers in the abattoir. However, this assertion was not substantiated in an experimental study in which lambs were dosed with infective A suum eggs. This produced, at the worst, small trivial lesions (up to 2 mm diameter) which would probably have been missed at meat inspection under commercial conditions. No evidence of ascarid lesions was observed in the livers of 5873 lambs and hoggs slaughtered between June and August. The most important causes of rejection were lesions caused by Cysticercus tenuicollis and migrating Fasciola hepatica, and these accounted for 90 and 8 per cent, respectively, of 1337 livers rejected either totally or partially by the meat inspectors.