The pathology of Cestrum laevigatum (Schlechtd.) poisoning in cattle.

The clinical features and pathological findings of 6 steers drenched with dried plant material of Cestrum laevigatum are described. Doses ranging from 0.5 to 10 g/kg/day were given intraruminally for 1 to 38 days. Animals that received 5 to 10 g/kg/day showed nervous signs including ataxia, muscle tremors, hypersensitivity and intermittent chewing. Clinical signs in the steers which received 0,5 to 4 g/kg/day were mild. High doses induced moderate to severe hepatosis characterized by centrilobular to midzonal coagulative necrosis, haemorrhage and congestion. At lower rates only mild hepatic lesions, characterized by disappearance of hepatocytes and collapse of the reticulin stroma in the centrilobular areas were evident. Ultrastructural changes were primarily limited to the hepatocytes and comprised degeneration, necrosis and fatty change. Degeneration and necrosis of endothelial cells and disruption of sinusoidal walls were occasionally observed.