Neurotoxicity in calves induced by the plant, Nierembergia hippomanica Miers var. violacea Millan in South Africa

The plant Nierembergia hippomanica var. violacea has been incriminated in f ield outbreaks of neurotoxicity in calves in the Free State Province. Hepat otoxicity and electrocardiogram (ECG) deviations were induced in a sheep do sed with 5 g/kg dried plant material on four consecutive days. A calf dosed with 2,5 g/kg dried plant material, on two consecutive days, did not show overt clinical changes. Voluntary ingestion of approximately 30 g/kg fresh flowering plants by a second calf resulted in nervous signs characterized b y chewing motions, protrusion of the tongue, dysphagia, hypermetria, ataxia , paresis and lateral recumbency Salivation, dehydration and cardiac irregu larities completed the clinical picture. Clinical chemistry changes reveale d muscle damage and increased serum urea and creatinine concentrations indi cative of kidney involvement. This is the first confirmed outbreak of Niere mbergia hippomanica var. violacea intoxication of stock in South Africa.