Serum changes and histologic liver lesions due to experimental ingestion of ragwort (Senecio erraticus) in sheep.

Eight 1-year-old Romney-Marsh female sheep were used to test the effect of Senecio erraticus (ragwort). Animals were fed for 60 days on a standard diet incorporating 20% dried ground ragwort. Morphology of the livers was studied by serial biopsy and function by changes in plasma bilirubin concentration, the half-life of bromosulphthalein (BSP), and by the activity of glutamate dehydrogenasa (GD) in plasma during and after Senecio ingestion. All sheep had an increase in bilirubin concentration and GD activity in their plasma and in BSP half-life. These values returned to normal 30 days after ragwort ingestion ceased. Histological studies showed Kupffer cell hypertrophy, fatty degeneration and megalocytosis. These lesions almost disappeared 60 days after stopping Senecio ingestion.