Abstract:
The plant Nierembergia hippomanica var. violacea has been incriminated in field outbreaks of neurotoxicity
in calves in the Free State Province. Hepatotoxicity and electrocardiogram (ECG) deviations
were induced in a sheep dosed 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 by chewing motions, protrusion of the tongue, dysphagia, hypermetria, ataxia,
paresis and lateral recumbency. Salivation, dehydration and cardiac irregularities completed the clinical
picture. Clinical chemistry changes revealed muscle damage and increased serum urea and creatinine
concentrations indicative of kidney involvement. This is the first confirmed outbreak of Nierembergia
hippomanica var. violacea intoxication of stock in South Africa.
